To see the other types of publications on this topic, follow the link: Superabsorbent polymers (SAP).
Journal articles on the topic 'Superabsorbent polymers (SAP)'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Superabsorbent polymers (SAP).'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Melendres, Ariel, Judy An Antang, and Christian Jake Manacob. "Investigation of superabsorbent polymer absorbency at reduced chemical potential of water." MATEC Web of Conferences 268 (2019): 04010. http://dx.doi.org/10.1051/matecconf/201926804010.
Full textAbstract:
Different types of superabsorbent polymers (SAP) exhibiting varied absorbency properties were investigated for their performances at varying concentrations of an electrolyte. Water chemical potential, which is a function of concentration and pressure, was interpreted as a major parameter for absorbency and swelling properties of SAP. Superabsorbent polymers that were investigated gave different values of permeability which was carried out in a layer of swelled superabsorbent polymer. This result revealed differences on the structure of the superabsorbent polymers particularly on the crosslinking density. SAP’s absorbency properties were further tested and a correlation between the quantity of absorption and the chemical potential of water in terms of sodium chloride concentration was developed using experimental data on free swelling capacity and absorption under pressure. Results showed decreasing quantity of absorption by the superabsorbent polymers with decreasing chemical potential of water with higher reduction in the absorbency at higher pressure applied on the swelled SAP.
2
Yu, Cong, Kamyar Malakpoor, and Jacques M. Huyghe. "A three-dimensional transient mixed hybrid finite element model for superabsorbent polymers with strain-dependent permeability." Soft Matter 14, no. 19 (2018): 3834–48. http://dx.doi.org/10.1039/c7sm01587a.
Full text
3
Sudhakar, Dr K., Leo Amalraj, V. Lakshmi Tejaswini, N. Mourya Sree, P. Divya Harshitha, and M. Rubika Julie. "Eco-friendly Biodegradable Super Absorbent Polymers (SAPs); An Effective Water Retainer and Agrofertilizer." Alinteri Journal of Agriculture Sciences 36, no. 1 (June 29, 2021): 753–56. http://dx.doi.org/10.47059/alinteri/v36i1/ajas21105.
Full textAbstract:
A polymer is a material which consists of very large molecules, or macromolecules, composed of many repeating subunits. They are classified as synthetic and natural polymers both play essential roles in everyday life due to their broad spectrum of properties. The foremost important class of polymers is superabsorbent polymer (SAP) materials. They are hydrophilic networks which absorb and retain large amounts of water. SAPs are originally divided into two main classes. They are Synthetic (Petrochemical based) and Natural (e.g.; Polysaccharide and Polypeptide based). Most of the present superabsorbent polymers are frequently produced from acrylic acid and acrylamide solution or inverse-suspension polymerization techniques. These are not biodegradable and are harmful to the environment that causes pollution. So, we sought to make biodegradable SAP that can act as a fertilizer to improve the soil quality and water conservation in agricultural land.
4
Mechtcherine, Viktor. "Use of superabsorbent polymers (SAP) as concrete additive." RILEM Technical Letters 1 (November 29, 2016): 81. http://dx.doi.org/10.21809/rilemtechlett.2016.18.
Full textAbstract:
Superabsorbent polymers (SAP) are new, very promising multipurpose chemical admixtures for concrete. They make available a number of new possibilities with respect to the control of free water in the mixture. In turn they contribute to the control of the rheological properties of fresh concrete and to the mitigation of autogenous and plastic shrinkage through internal curing. Furthermore, pore systems built up as a result of SAP addition seem to remain stable regardless of the consistency of the concrete, the addition of superplasticizers, or the method of placement and compacting. Thus, SAP can be used as an alternative to air-entrainment agents. This article presents these and other potential practical applications of SAP in concrete construction.
5
Whitmore, Darryl L. "Nonwovens Containing Immobilized Superabsorbent Polymer Particles." International Nonwovens Journal os-12, no. 3 (September 2003): 1558925003os—12. http://dx.doi.org/10.1177/1558925003os-1200311.
Full textAbstract:
In the early 1980's Johnson & Johnson developed a revolutionary process for the production of webs containing superabsorbent polymers (SAP) produced by in-situ polymerization of partially neutralized acrylic monomers directly on a synthetic nonwoven substrate [1, 2, 3, 4]. A fresh look at this forgotten technology will be presented from both a manufacturing and application perspective. In particular, In-situ, SAP-containing nonwovens offer many unique properties for application in the personal hygiene industry, such as, improved fluid acquisition, permeability, compressibility and pH control. These materials also provide a more homogenous SAP distribution, eliminate the need for SAP powder handling and have superior wet integrity as compared to conventional fluff pulp/SAP air laid structures. This technology also offers some unique opportunities for designing and manufacturing profiled absorbent articles with specific zones tailored to perform specific functions.
6
Otcovská, Tereza, Petr Bittnar, and Pavel Padevět. "Properties of the Superabsorbent Polymer in Cement Paste." Key Engineering Materials 714 (September 2016): 40–43. http://dx.doi.org/10.4028/www.scientific.net/kem.714.40.
Full textAbstract:
The article is devoted to compare the properties of super absorbent polymers useful in concrete. The idea of using super absorbent polymers (SAP) is the replacement of the treatment water in concrete structures. The properties are compared in terms of change of the volume and the ability of spilling of cement mixture which contains SAP.
7
Li, Gui, Marianne Tange Hasholt, and Ole Mejlhede Jensen. "Environmental Assessment of Frost-resistant Concrete with Superabsorbent Polymers." Nordic Concrete Research 63, no. 2 (December 1, 2020): 43–62. http://dx.doi.org/10.2478/ncr-2020-0011.
Full textAbstract:
Abstract Air-entraining agents (AEA) are normally used to improve the frost resistance of concrete. However, it is not possible to accurately control the air void system in concrete with AEA. Thus, a significant loss of concrete strength is caused by over-dosing voids, and this increases the environmental impact from concrete structures. Superabsorbent polymer (SAP) can also be used to produce frost-resistant concrete. Compared to AEA, it can be used to precisely engineer the air void structure of concrete, promote cement hydration, and mitigate self-desiccation cracks. In this study, life cycle assessment methodology is applied to evaluate the overall environmental impact of frost-resistant concrete based on AEA and SAP, respectively. The results illustrate that frost-resistant concrete with SAP has a lower environmental impact than frost-resistant concrete with AEA if the strength and durability of concrete are considered in the defined functional unit. In addition, frost-resistant concrete with SAP reduces the environmental burdens of the vertical elements such as columns, but it increases the environmental load of the horizontal elements such as slabs, where the strength increase cannot be utilized. Moreover, the inventory data for AEA and SAP can affect the impact assessment results.
8
Santos, Karyne Ferreira dos, António Carlos Bettencourt Simões Ribeiro, Eugênia Fonseca da Silva, Manuel Alejandro Rojas Manzano, Leila Aparecida de Castro Motta, and Romildo Dias Toledo Filho. "Effect of the Combination of Superabsorbent Polymers for Autogenous Shrinkage Control with Steel Fibers of High-Performance Concrete under Uniaxial Tension Using DIC." Materials 13, no. 20 (October 17, 2020): 4638. http://dx.doi.org/10.3390/ma13204638.
Full textAbstract:
This paper presents a study of the effect of a superabsorbent polymer (SAP) for autogenous shrinkage control on the uniaxial tensile behavior of steel fiber reinforced concrete (SFRC). The use of fibers and SAP potentially increases the durability of the concrete, preventing cracking by autogenous shrinkage and enhancing post-cracking behavior. Furthermore, SAP can provide further hydration for self-healing purposes and improve the ductility of the SFRC. In order to evaluate the effect of the addition of SAP in SFRC, dog-bone SFRC specimens with different dosages of superabsorbent polymers were cast and tested under uniaxial tension. The digital image correlation (DIC) technique was used to understand the effect of SAP on the steel fibers’ crack-bridging mechanisms. Surface strains and crack openings were inferred using the DIC technique. The effect of SAP and fibers on fresh and hardened concrete was individually investigated by flow tests and compressive strength tests. Autogenous shrinkage was measured in plain concrete to investigate the minimum SAP content required to mitigate autogenous shrinkage of 0.3%. The use of 0.3% SAP was also sufficient to reach multiple cracking behavior. This content of SAP completely suppressed the autogenous shrinkage with minimal side effects on compressive strength. An analytical formulation for the tensile behavior of SFRC was developed using the variable engagement model, presenting a mean correlation of R2 of 0.97 with the experimental results.
9
Sahi, Amal, Khadija El Mahboub, Tikou Belem, Abdelkabir Maqsoud, and Mamert Mbonimpa. "Dewatering of Mine Tailings Slurries Using Superabsorbent Polymers (SAPs) Reclaimed from Industrial Reject of Baby Diapers: A Preliminary Study." Minerals 9, no. 12 (December 13, 2019): 785. http://dx.doi.org/10.3390/min9120785.
Full textAbstract:
Traditional deposition of tailings slurry in a tailings storage facility (TSF) can create risks of dike failure. In order to minimize these risks and slurry spillage, the surface deposition technique of densified tailings (DT) through dewatering of the slurry has emerged. The DT technique has the potential to maximize water reuse, improve the shear strength of surface tailings, and reduce the ecological footprint of TSF. The consistency of DT covers a continuum ranging from thickened state, to paste state, to dry state. Despite its efficiency and economic feasibility, DT densification using thickeners sometimes proves unable to achieve the design target solids mass concentration (Cw%). Hence, the use of superabsorbent polymers (SAPs) seems to represent a promising alternative, owing to their higher water absorbent capacity. In this paper, superabsorbent polymers (SAPs) reclaimed from industrial reject of baby diapers (Na-polyacrylates) are explored as a promising alternative to mine tailings slurries dewatering. To this end, laboratory-scale dewatering tests have been performed using two grades of Na-polyacrylate SAPs (grade 1 SAP = SAG-A06P coarse-grained, and grade 2 = SAG-M01P-100 medium-grained) for the tailings slurries densification. A higher water absorbency (or swelling capacity) was observed using the coarser SAPs (SAG-A06P) compared to the finer SAPs (SAG-M01P-100). The preliminary results showed that a SAP volume dosage in the range 10–13 kg of SAP/m3 of slurry allowed achieving a final solids mass concentration (Cw%_final) ≥ 70%, despite the occurrence of gel-blocking phenomenon.
10
Kočí, Jan, Akbota Begaly, and Jan Fořt. "Hygric parameters of cement-lime plasters modified by superabsorbent polymers." MATEC Web of Conferences 282 (2019): 02059. http://dx.doi.org/10.1051/matecconf/201928202059.
Full textAbstract:
Moisture level significantly affects durability of constructions, their thermal performance and quality of indoor air. As the building envelopes are subjected to the effect of changing weather conditions from the exterior and numerous sources of water vapor from interior, the proper design may significantly increase the performance of the construction. In this paper, modified plasters with different amount of super absorbent polymers (SAP) are analyzed in the laboratory conditions in terms of their hygric and mechanical properties. The results showed that addition of SAP in the plasters may be promising for the utilization in building envelopes composition. However, the exact amount of SAP is crucial as the results revealed that if more that 1% of SAP is added to the plasters, the poor mechanical properties may exclude the plasters from real applications.
11
Whang, Minji, Hyeonji Yu, and Jungwook Kim. "Superabsorbent Polymer Network Degradable by a Human Urinary Enzyme." Polymers 13, no. 6 (March 17, 2021): 929. http://dx.doi.org/10.3390/polym13060929.
Full textAbstract:
Owing to its superior water absorption capacity, superabsorbent polymer (SAP) based on a poly (acrylic acid) network is extensively used in industrial products such as diapers, wound dressing, or surgical pads. However, because SAP does not degrade naturally, a massive amount of non-degradable waste is discarded daily, posing serious environmental problems. Considering that diapers are the most widely used end-product of SAP, we created one that is degradable by a human urinary enzyme. We chose three enzyme candidates, all of which have substrates that were modified with polymerizable groups to be examined for cleavable crosslinkers of SAP. We found that the urokinase-type plasminogen activator (uPA) substrate, end-modified with acrylamide groups at sufficient distances from the enzymatic cleavage site, can be successfully used as a cleavable crosslinker of SAP. The resulting SAP slowly degraded over several days in the aqueous solution containing uPA at a physiological concentration found in human urine and became shapeless in ~30 days.
12
Jung, Andre, Manuel B. Endres, and Oliver Weichold. "Influence of Environmental Factors on the Swelling Capacities of Superabsorbent Polymers Used in Concrete." Polymers 12, no. 10 (September 24, 2020): 2185. http://dx.doi.org/10.3390/polym12102185.
Full textAbstract:
Superabsorbent polymers (SAP) are of major interest as materials to control the cement hydration process. The swelling behavior of the SAPs significantly influences the performance of the resulting concrete by slowly releasing polymer-bound water in order to maintain a consistent w/c value. A round-robin test conducted by the RILEM Technical Committee 260-RSC showed that the same batch of polymer can lead to large deviations in concrete performance and this was assumed to originate in different storage conditions of the SAP. In this contribution the change in the performance of two SAPs, a crosslinked poly(acrylate) and a crosslinked poly(acrylate-co-acrylamide), was assessed after ageing in standard climate, at 50 °C, and under UV irradiation. During storage in standard climate or 50 °C, ageing led to dehydration of the SAP, and this subsequently led to a higher water uptake during swelling. By contrast, UV irradiation reduced the water uptake, most likely as a result of photo-crosslinking. Dynamic water vapor sorption experiments indicated a strong dependence of the water uptake on both the ambient humidity and the temperature. As a result, cement mixtures containing SAP must be calculated on the dry mass of the SAP rather than the actual weight on site. A standard procedure of how to pack and handle SAP to be used in concrete is also provided.
13
Yang, Jin, Fa Zhou Wang, and Yun Peng Liu. "Comparison of Ordinary Pores with Internal Cured Pores Produced by Superabsorbent Polymers." Advanced Materials Research 1129 (November 2015): 315–22. http://dx.doi.org/10.4028/www.scientific.net/amr.1129.315.
Full textAbstract:
Porous cementitious mixtures were prepared with two different spherical particles: expanded polystyrene (EPS) and superabsorbent polymer (SAP). The effect of EPS and SAP on the compressive strength, ultrasonic transmission, internal relative humidity and hydration degree under different volume fraction were studied. Results indicated that SAP matrix possessed much higher compressive strength (30-60%, 28d), ultrasonic transmission velocity, internal humidity (11-13%RH, 28d) and hydration degree (13-21%, 28d) than EPS matrix, which indicated that the desorption of SAP accelerated the hydration and increased the compactness of the surrounding cement paste. The internal cured pores left by SAP might have been strengthened which was different from ordinary pores produced by EPS.
14
Melendres, Ariel Verzosa, and Rolan Pepito Vera Cruz. "Absorption of Water Vapor Using Superabsorbent Polymer Composite Material." Key Engineering Materials 858 (August 2020): 129–39. http://dx.doi.org/10.4028/www.scientific.net/kem.858.129.
Full textAbstract:
The ability of superabsorbent polymers (SAP) to absorb water vapor was studied. A multilayer composite material was prepared where SAP particles were spread in the fluffy fibrous layer located in the middle of the composite structure. Distribution of SAP within the composite material permits air to pass through its porous structure effectively hence allowing efficient contact of air with SAP. SAP was able to decrease the relative humidity of air of a 3-L cabinet from 96% relative humidity (RH) to 52% and 49 % (RH) in 18 hours using 2 g and 4 g of SAP respectively. Study on the water vapor absorption ability of SAP placed together with pure water in a closed cabinet was conducted with and without convective air transport effect. Convective air transport was done by activating the 12 V fan allowing air recirculation speed at rates corresponding to constant voltage settings of 6 V and 12 V. Higher SAP water vapor absorption rate was obtained at higher air recirculation speed. SAP particles swelled after water vapor absorption with slight decrease in the porosity of composite material as observed through the digital microscope.
15
Jahan, Mohsen, and Mehdi Nassiri Mahallati. "Can Superabsorbent Polymers Improve Plants Production in Arid Regions?" Advances in Polymer Technology 2020 (March 26, 2020): 1–8. http://dx.doi.org/10.1155/2020/7124394.
Full textAbstract:
Superabsorbent polymers (SAPs) have shown to be quite effective and useful in acting as a reservoir for water and some nutrients in arid and semiarid regions. There are many studies in Iran that have been performed in relation to SAPs and their useful application in agriculture; however, there is still a lack of its applied definition in arid regions. Therefore, this study was conducted with the aim of doing a meta-analysis of the results of studies conducted in Iran and answering a general question about whether the application of SAPs has been effective in enhancing the production or not, and if so, how much of SAP is recommended. To conduct this research, articles published during 2006–2016 on the subject of the effects of different rates of SAP application on yield and yield components of crops (including cereals, legumes, and medicinal and grassland plants) were investigated. The results of the meta-analysis showed that the mean consumption rate of SAPs for cereals, legumes, and medicinal and grassland plants was 83, 322, 1031, and 210 kg ha−1, respectively, and that, at these SAP application rates, the mean seed yield in cereals, medicinal plants, and legumes increased by 15.2, 12.6, and 38% (equivalent to 1059, 345, and 452 kg ha−1), respectively, compared with the control. Dry matter response to superabsorbent application was slower compared with the seed yield response. The mean consumption of 83 kg ha−1 of superabsorbent for cereals increased seed yield by 15.2% on average. According to the results, it seems that the application of 100 kg SAP ha−1 is the most appropriate rate for increasing seed and dry matter yields and satisfying economic aspects. These study findings may shed light on the environment and socioeconomic concerns and improve efficacy and reduction of costs.
16
Ismillayli, Nurul, Siti Raudhatul Kamali, Surya Hadi, and Dhony Hermanto. "Synthesis of Biodegradable Superabsorbent Polymers from Carboxymethyl Cellulose/Humic Acid." Acta Chimica Asiana 2, no. 2 (August 15, 2019): 95. http://dx.doi.org/10.29303/aca.v2i2.8.
Full textAbstract:
Superabsorbent polymer (SAP) blend has been synthesized from carboxymethyl cellulose (CMC), humic acid, and aluminum sulphate octadecahydrate cross-linker. SAP is hydrophilic networks that can absorb and retain huge amount of water within their structures. Humic acid as starting material of polymer, was isolated from subgrade Batujai Dam by using IHSS method. Water Absorption Capacity (WAC) measurement, FTIR analysis, and agitation tests to investigate the cross-linking process and which of Al3+ and SO42- ions causes the crosslinking are carried out. Optimum cross-linking ratio of CMC and cross-linker appeared to be 2wt% corresponded to WAC determination. FTIR spectrum of CMC/humic acid blend and agitation test showed that CMC react with humic acid during polymerization process via Al3+ ion.
Keywords: carboxymethyl cellulose; Al3+ ion; humic acid; superabsorbent polymer.
17
Prasetyaningrum, Aji, Al Farrel A. Raemas, Nur Rokhati, and Bakti Jos. "Application of Glyoxal Acrylamide Modified Κ-Carrageenan as A Superabsorbent Polymer in Drug Delivery System." Reaktor 20, no. 3 (October 13, 2020): 150–58. http://dx.doi.org/10.14710/reaktor.20.3.150-158.
Full textAbstract:
The hydrogel is superabsorbent polymers (SAP) that are biodegradable and can be obtained from polysaccharides, lipids, and proteins. Polysaccharides include cellulose, starch and their derivatives, seaweed extracts such as carrageenan, alginate, pectin, and chitosan. Carrageenan is the result of the extraction of red seaweed sap with an alkaline solution. The main objective of this study was to simultaneously increase the strength and properties of κ-carrageenan SAP film with the addition of glyoxal and acrylamide as crosslinkers. The addition of acrylamide (variated from 1 to 7 % b/v) into the k-Carrageenan based SAP hydrogel compound and the presence of glyoxal as crosslink agent (variated from 0 to 1,0 % v/v). The physical properties of the SAP films were analyze using swelling degree and tensile strength. The structural and morphological properties of composite films were analyzed using Fourier Transform Infrared (FTIR) and Scanning Electron Microscopy (SEM). In addition, the effect of pHs on the releasing drug Poly(vinylpyrrolidone)-Iodine was investigated. This research shows that the addition of acrylamide and glyoxal can improve the physical properties of the modified κ-carrageenan film. Characterization using SEM shows that the addition of glyoxal causes the formation of tissue fibers in SAP. FTIR spectra indicated the formation of cross bonds in modified SAP film at 3294.42 cm-1 (carboxylic acid). The treatment under alkaline conditions will increase drug release ability.Keywords: κ-carrageenan; hydrogels; acrylamide; glyoxal; drug delivery
18
Fořt, Jan, Jan Kočí, Jaroslav Pokorný, and Robert Černý. "Influence of Superabsorbent Polymers on Moisture Control in Building Interiors." Energies 13, no. 8 (April 17, 2020): 2009. http://dx.doi.org/10.3390/en13082009.
Full textAbstract:
Moisture loads in building interiors are accompanied by a deterioration of the indoor air quality. Such a phenomenon may induce serious health risks for building inhabitants as well as degradation of furnishing. Unfortunately, the employment of additional heat, ventilation and air conditioning (HVAC) devices does not comply with the sustainability principle due to increased energy consumption, thus cannot be viewed as an efficient solution. This study deals with the use of superabsorbent polymers (SAP) in cement-lime plasters, thus extends the current state of knowledge and outlines further possible development of novel moisture responsive plasters since lightweight aggregates do not provide the desired performance. To be specific, this paper contemplates the experimental analysis of novel plasters modified by 0.5, 1 and 1.5 wt. % of SAP to obtain input parameters for computational modeling. Based on the obtained outputs, the incorporation of SAP admixture resulted in a substantial increase in moisture transport properties including the water absorption coefficient and water vapor diffusion properties. The performed computational modeling revealed a considerable reduction of relative humidity fluctuations, thus mitigation of potential health issues associated with undesired moisture content in building interiors. Achieved results indicate that the SAP enhanced plasters have substantial passive moisture buffering performance and thus may contribute to the improvement of indoor air quality.
19
Li, Xue Ying, Ya Ding Zhao, and Xin Wei Ma. "Shrinkage and Cracking of Cement Composites Containing Internal Curing Stuff." Advanced Materials Research 163-167 (December 2010): 766–69. http://dx.doi.org/10.4028/www.scientific.net/amr.163-167.766.
Full textAbstract:
The influence of superabsorbent polymers (SAP) as internal curing stuff on the restrained shrinkage and cracking of concrete was investigated. Results show that SAP in the mortar with slag and silica fume increases the compressive train of the steel ring, but postpones the initial cracking time of the mortar from 5 days to 6.5 days and reduces the crack width by 25% at age of 28 days.
20
Hong, Geuntae, Chiwon Song, and Seongcheol Choi. "Autogenous Healing of Early-Age Cracks in Cementitious Materials by Superabsorbent Polymers." Materials 13, no. 3 (February 4, 2020): 690. http://dx.doi.org/10.3390/ma13030690.
Full textAbstract:
The effect of superabsorbent polymers (SAPs) on autogenous crack healing in cementitious materials with early-age cracking was investigated. SAP-containing samples exposed to wet/dry cycles showed better autogenous healing than those only exposed to wet conditions, as determined by water flow and compressive strength recovery tests. The water flow rates through cracks (380 ± 40 µm) in cement paste and cement mortar containing 1.0% SAP decreased by around 97.1–100% and 79.7–90.7%, respectively, after 14 cycles of healing compared to 1 cycle. Although the initial compressive strength decreased with SAP addition, it recovered somewhat after a 28-d healing period. Microscopy and spectroscopy results identified CaCO3 and/or calcium silicate hydrate (CSH) as the main healing products.
21
Urgessa, Girum, Ki-Bong Choi, and Jung Yeon. "Internal Relative Humidity, Autogenous Shrinkage, and Strength of Cement Mortar Modified with Superabsorbent Polymers." Polymers 10, no. 10 (September 28, 2018): 1074. http://dx.doi.org/10.3390/polym10101074.
Full textAbstract:
Laboratory evaluations were performed to investigate the effect of internal curing (IC) by superabsorbent polymers (SAP) on the internal relative humidity (IRH), autogenous shrinkage, coefficient of thermal expansion (CTE), and strength characteristics of low water-cement ratio (w/c) mortars. Four types of SAP with different cross-linking densities and particle sizes were used. Test results showed that the SAP inclusion effectively mitigated the IRH drops due to self-desiccation and corresponding autogenous shrinkage, and the IC effectiveness tended to increase with an increased SAP dosage. The greater the cross-linking density and particle size of SAP, the less the IRH drop and autogenous shrinkage. The trend of autogenous shrinkage developments was in good agreement with that of IRH changes, with nearly linear relationships between them. Both immediate deformation (ID)-based and full response-based CTEs were rarely affected by SAP inclusions. There were no substantial losses in compressive and flexural strengths of SAP-modified mortar compared to reference plain mortar. The findings revealed that SAPs can be effectively used to reduce the shrinkage cracking potential of low w/c cement-based materials at early ages, without compromising mechanical and thermal characteristics.
22
Lei, Xiao, Rui Wang, Hanwan Jiang, Faxiang Xie, and Yanni Bao. "Effect of Internal Curing with Superabsorbent Polymers on Bond Behavior of High-Strength Concrete." Advances in Materials Science and Engineering 2020 (December 30, 2020): 1–13. http://dx.doi.org/10.1155/2020/6651452.
Full textAbstract:
High-strength concrete (HSC) is widely used in engineering due to its high strength and durability. However, because of its low water-to-cement ratio, external curing water hardly enters the dense internal structure of HSC so that high self-desiccation shrinkage often takes place. As a result, superabsorbent polymers (SAP) are added as an internal curing material to effectively reduce the shrinkage of high-performance concrete. Meanwhile, the bond performance between reinforcing steel and SAP HSC concrete remains unknown. In this paper, the bond performance of HSC mixed with SAP is studied by pull-out tests, and the results were obtained as follows: (1) the bond strength of HSC mixed with SAP increased first and then decreased with the increase of SAP content; (2) the slip at ultimate bond strength of HSC with SAP decreased with the increase of compressive strength; (3) a prediction model of the stress-slip relationship between steel rebars and HSC was established.
23
Shim, Yewon, Geuntae Hong, and Seongcheol Choi. "Autogenous Healing of Early-Age Cementitious Materials Incorporating Superabsorbent Polymers Exposed to Wet/Dry Cycles." Materials 11, no. 12 (December 6, 2018): 2476. http://dx.doi.org/10.3390/ma11122476.
Full textAbstract:
This study experimentally investigated the autogenous healing performances of cementitious materials incorporating superabsorbent polymers (SAPs) after exposure to eight cycles of wet/dry conditions. In each cycle, cracked cement paste specimens with different SAP dosages were exposed to wet conditions for 1 h, during which capillary water absorption tests were conducted, and then exposed to dry conditions for 47 h. The test results reveal that the initial sorptivity values of the reference, 0.5% SAP, 1.0% SAP, and 1.5% SAP specimens after one cycle were decreased by 22.9%, 36.8%, 42.8%, and 46.3%, respectively, after eight cycles. X-ray micro-computed tomography analysis showed that the crack volume percentages filled with healing products were 1.1%, 1.6%, 2.2%, and 2.9% in the reference, 0.5% SAP, 1.0% SAP, and 1.5% SAP specimens, respectively. As the cycling was repeated, the reduction ratio of the initial sorptivity and the quantity of healing products were increased with increases in SAP dosage. Furthermore, more healing products were distributed near SAP voids than in other sections in the specimens. This study demonstrates that the incorporation of SAPs in cementitious materials can enhance the autogenous healing performances of materials exposed to cyclic wet/dry conditions.
24
Dhiman, Jaskaran, Shiv O. Prasher, Eman ElSayed, Ramanbhai Patel, Christopher Nzediegwu, and Ali Mawof. "Use of Polyacrylamide Superabsorbent Polymers and Plantain Peel Biochar to Reduce Heavy Metal Mobility and Uptake by Wastewater-Irrigated Potato Plants." Transactions of the ASABE 63, no. 1 (2020): 11–28. http://dx.doi.org/10.13031/trans.13195.
Full textAbstract:
HighlightsAmending soil with SAP+BC and SAP reduced Cd, Cu, and Zn uptake into potato tubers.SAP+BC treatment led to greater Cd and Zn retention in topsoil.Acrylamide monomers were not detected in potatoes grown in SAP-amended soil.Potato peels accumulated higher concentrations of heavy metals than tuber flesh.Abstract. Agriculture is the largest consumer of freshwater; therefore, use of alternate sources for irrigation, such as wastewater, could alleviate increasing stress on freshwater resources. However, wastewater may contain contaminants such as heavy metals (Cd, Cr, Cu, Fe, Pb, and Zn), which could be taken up by food crops and/or contaminate groundwater. To reduce the mobility of heavy metals in soil and deter their uptake by potatoes ( L.) irrigated with synthetic wastewater, polyacrylamide superabsorbent polymer (SAP) and a mixture of SAP and plantain peel biochar (SAP+BC) were tested as soil amendments. The experiment was performed in field lysimeters packed with sandy soil. SAP was incorporated into the soil layer from 0.15 to 0.25 m below the surface and BC was mixed into the top 0.10 m of soil, both at an application rate of 1% (w/w). Leachate and composite soil samples from different depths, collected after each irrigation event, were analyzed for heavy metals. Upon harvest, different plant parts were subjected to heavy metal analysis. Compared to the untreated control, the SAP+BC treatment led to significantly greater (p < 0.05) retention of Cd and Zn in the topsoil while significantly reducing (p < 0.05) Cd, Cu, and Zn uptake into potato tuber flesh tissue and Cd uptake into tuber peels. The SAP treatment also significantly reduced (p < 0.05) Cd uptake in the tuber as compared to the control. Acrylamide monomers were not detected in tuber flesh and peel samples for all treatments, indicating possible safe use of SAP and BC in soils to reduce heavy metal leaching and uptake by plants. Keywords: Biochar, Heavy metals, Hydrogels, Lysimeter, Plant uptake, Superabsorbent polymers, Wastewater.
25
Sánchez-Orozco, Raymundo, Beatriz Timoteo-Cruz, Teresa Torres-Blancas, and Fernando Ureña-Núñez. "VALORIZATION OF SUPERABSORBENT POLYMERS FROM USED DISPOSABLE DIAPERS AS SOIL MOISTURE RETAINER." International Journal of Research -GRANTHAALAYAH 5, no. 4 (April 30, 2017): 105–17. http://dx.doi.org/10.29121/granthaalayah.v5.i4.2017.1800.
Full textAbstract:
This study was conducted to explore the potential of superabsorbent polymers (SAPs) from used disposable diapers as soil moisture retainer. Swelling behavior of the proposed hydrogel in response to external stimuli such as salt solutions, temperature and pH was studied. In addition, laboratory experiments were carried out to evaluate the effects of incorporation hydrogel on germination of bean (Phaseolus vulgaris L.) and pumpkin (C. pepo) seeds. The structure of the used superabsorbent was characterized by Fourier transform infrared spectroscopy (FTIR). The results indicate that the proposed SAP exhibited a maximum swelling capacity of 189 g-g-1 of dry gel. It was observed that the swelling capacity decreased with an increase in the ionic strength of the swelling medium. When this SAP was mixed with sandy soil, the mixture was able to lose water more slowly. The seeds germination and seedling growth was remarkably influenced by the application of 0.5, 1.0 and 2.0 w/w% of SAP compared to the untreated soil. Therefore, it follows that it is possible to take advantage of SAPs property from used disposable diapers to retain the moisture in soil as an alternative to value the use of such waste, showing that it has potential for agricultural applications.
26
Fořt, Jan, Petr Hotěk, Martin Mildner, Jitka Krejsová, and Robert Černý. "Effect of superabsorbent polymer admixtures on hygric and thermal properties of cement mortar." E3S Web of Conferences 172 (2020): 14011. http://dx.doi.org/10.1051/e3sconf/202017214011.
Full textAbstract:
Materials known as superabsorbent polymers (SAP) or hydrogels are currently used in quite a few applications, ranging from diapers or napkins to nutrient carriers and soil conditioners. The great ability of SAPs to absorb and hold a significant amount of water can be utilized well also in the construction sector. For instance, SAPs can serve as effective admixtures for mitigation of autogenous shrinkage of high-performance concrete, frost protection, or cracks sealing. In this paper, basic physical, hygric and thermal properties of cement mortars containing superabsorbent polymer admixtures are analyzed. Basic physical characteristics are measured using the water vacuum saturation method and helium pycnometry. Moisture diffusivity is determined by utilizing the results of water sorptivity measurements, water vapor diffusion permeability is measured by the cup method. Sorption isotherms are determined by the desiccator method in the range of relative humidity of 11% – 96%. Thermal conductivity and specific heat capacity are measured by pulse method. Experimental results show a very significant dependence of all hygric and thermal parameters on the SAP dosage in the mix.
27
De Meyst, Laurence, Els Mannekens, Maria Araújo, Didier Snoeck, Kim Van Tittelboom, Sandra Van Vlierberghe, and Nele De Belie. "Parameter Study of Superabsorbent Polymers (SAPs) for Use in Durable Concrete Structures." Materials 12, no. 9 (May 10, 2019): 1541. http://dx.doi.org/10.3390/ma12091541.
Full textAbstract:
Superabsorbent polymers (SAPs) can be added to a concrete mixture to provide internal curing and reduce the risk for early-age shrinkage cracking. Hence, they can help to increase the overall durability of concrete structures. The type, swelling characteristics, kinetics of water release, amount and particle size of the SAPs will dictate their effectiveness for this purpose. In this paper, SAPs with different cross-linking degrees, particle sizes and amount of solubles are investigated. By varying these parameters, insight can be gained on the influence of each of these parameters on SAP properties such as the swelling capacity. In a next step, the SAPs can be implemented in mortar to assess their influence on mortar properties like workability, compressive strength or hydration kinetics. Based on these results, the ‘ideal’ SAP with tunable properties for a specific concrete application can be selected. For this purpose, an anionic SAP was synthesized with varying amounts of cross-linker and ground to particle sizes with d50 varying between 10 and 100 µm. The swelling capacity in demineralised water of 40 µm SAP particles increased with a decreasing degree of cross-linker from 66 g/g SAP with 1 mol% cross-linker to 270 g/g SAP in case of 0.15 mol% cross-linker, and was about three to four times larger than the swelling capacity in the prepared cement filtrate. The SAPs were tested for their effect on mortar workability, cement hydration kinetics and mechanical properties of the hardened mortar. With proper compensation for the absorbed water by the SAPs, the mortar workability was not negatively affected and the reduction in flow over the first two hours remained limited. The SAPs with the lowest swelling capacity, resulting in the smallest total amount of macro pores formed, showed the smallest negative effect on mortar compressive strength (a reduction of 23% compared to the reference after 28 days for an addition of 0.5 m% SAP) and a negligible effect on cement hydration. The difference in strength with the reference decreased as a function of mortar age. When using SAPs with particle sizes in the range of 10–100 µm, no significant differences between the studied particle sizes were found concerning the mortar properties. With the ease of upscaling in mind, the need to purify the SAPs and to remove the non-cross-linked soluble fraction was further investigated. It was shown that the solubles had no effect on the mortar properties, except for increasing the setting time with almost 100%.
28
Mazari, Funda, Adnan Mazari, Antonin Havelka, and Jakub Wiener. "Effect of a Superabsorbent for the Improvement of Car Seat Thermal Comfort." Fibres and Textiles in Eastern Europe 25 (April 30, 2017): 83–87. http://dx.doi.org/10.5604/12303666.1228187.
Full textAbstract:
The use of super absorbent polymers (SAP) for moisture absorption and comfort is still unexplored. The aim of this work was to observe the application of super absorbent fibres in car seats for comfort purposes. In this research the efficiency of different SAP fibrous webs were determined under different moisture percentages to examine the sorption and desorption efficiency. A SAP fibrous web with low thickness and high moisture absorption were tested with a multilayer sandwich structure of a car seat cover to determine moisture absorption through the cover material. The standard Cup method was used to determine the moisture permeability of different car seat covers with a superabsorbent layer closed with impermeable polyurethane foam. It was observed that the SAP fibrous layers are very effective in absorbing and desorbing water vapour under extremely high and low moisture percentages. In extreme humid conditions (95%RH), 20g of the SAP layer absorbs nearly 70% of its weight in water vapour, reaching the maximum absorption capacity in 6 hours.
29
Misiewicz, Jakub, Arkadiusz Głogowski, Krzysztof Lejcuś, and Daria Marczak. "The Characteristics of Swelling Pressure for Superabsorbent Polymer and Soil Mixtures." Materials 13, no. 22 (November 10, 2020): 5071. http://dx.doi.org/10.3390/ma13225071.
Full textAbstract:
Superabsorbent polymers (SAPs) are used in agriculture and environmental engineering to increase soil water retention. Under such conditions, the swelling pressure of the SAP in soil affects water absorption by SAP, and soil structure. The paper presents the results of swelling pressure of three cross-linked copolymers of acrylamide and potassium acrylate mixed at the ratios of 0.3%, 0.5% and 1.0% with coarse sand and loamy sand. The highest values of swelling pressure were obtained for the 1% proportion, for coarse sand (79.53 kPa) and loamy sand (78.23 kPa). The time required to reach 90% of swelling pressure for each type of SAP differs. Samples of coarse sand mixed with SAP K2 in all concentrations reached 90% of total swelling pressure in 100 min, while the loamy sand mixtures needed only about 60 min. The results were the basis for developing a model for swelling pressure of the superabsorbent and soil mixtures, which is a fully stochastic model. The conducted research demonstrated that the course of pressure increase depends on the available pore capacity and the grain size distribution of SAPs. The obtained results and the proposed model may be applied everywhere where mixtures of SAPs and soils are used to improve plant vegetation conditions.
30
Mazanec, Oliver, Alessander Assmann, and Diana Eissmann. "Prediction of the swelling capacity of salt-insensitive superabsorbent polymers in concrete by rheological measurements." MATEC Web of Conferences 289 (2019): 02004. http://dx.doi.org/10.1051/matecconf/201928902004.
Full textAbstract:
A study on the macroscopic viscosity of a flowable, fine-grained high-strength mortar was conducted in order to estimate the swelling capacity of two salt-insensitive superabsorbent polymers (SAPs). In doing so, rotational rheometer measurements of the mortar modified with dry pre-mixed SAP were performed at several water-to-cement ratios (W/C), i.e. in the range 0.32 to 0.40. The swelling capacity of each SAP was estimated by correlating the fitted macroscopic viscosity vs. solid particle fraction curve with the curve of the plain mortar without addition of SAP, produced at the same W/C. The swelling capacities were found to yield 28 g pore water per g dry SAP (g/g) and 35 g/g, respectively. In addition to this new approach, two more practical relevant test methods were evaluated with respect to swelling capacity: first, comparative mortar spread tests, which were based on the use of the same fresh mortars but with less amount of superplasticizer, and second, tea bag tests with plain SAP immersed in an artificial pore solution. Only minor differences were found for the estimated swelling capacities. Hence the conclusion may be drawn that all three test methods are suitable for determining the swelling capacity of SAP in a cementitious environment.
31
Zhang, Wenxu, Qian Liu, Shengfang Liu, Jing Chen, Lulu Guo, Peng Wang, and Ziqiang Lei. "Study on Seed Emergence and Seedling Growth of Artemisia Desertorum with Superabsorbent Polymers." Polymers 12, no. 12 (November 30, 2020): 2873. http://dx.doi.org/10.3390/polym12122873.
Full textAbstract:
In this study, the emergence rate, emergence potential, root length, stem length, water consumption, and biomass around a root system were used as evaluation indexes, and we used the laboratory-prepared super absorbent resin watermelon rind (WMR)-p (AA–co–DAAM) (superabsorbent polymer 1—SAP1), WMR-p (AA–co–DAAM)/palygorskite (PGS) (SAP2) in a laboratory and commercially available water-retaining agents (SAPRX and SAPHDB) to assist the emergence of Artemisiadesertorum seeds and seedling growth; then, their water absorption and thermal stability were discussed. The results showed that the thermal stability of an SAP prepared in the laboratory and the water consumption during seed emergence, root length, and stem length after emergence were better than those of an SAP purchased on the market, and this information could help to promote the emergence and seedling growth of Artemisiadesertorum. While enhancing the drought resistance of plants, using a laboratory-produced SAP can effectively reduce the number of artificial irrigations.
32
Zhang, Jinbao, Song Li, and Jiahui Zhai. "Grey Prediction Model for Drying Shrinkage of Cement Concrete Made from Recycled Coarse Aggregate Containing Superabsorbent Polymers." Mathematical Problems in Engineering 2021 (January 29, 2021): 1–9. http://dx.doi.org/10.1155/2021/6662238.
Full textAbstract:
The aim of this paper is to investigate the effect of superabsorbent polymers (SAPs) on the drying shrinkage of the recycled concrete (RC). The natural aggregate (NA) was replaced by recycled aggregate at three replacement ratios (0%, 50%, and 100%). Then, the recycled concrete (RC) with different SAP contents was prepared. The performance of recycled concrete with different SAP content was analyzed with slump test, compressive strength test, and drying shrinkage test. GM (1, N) grey prediction model was utilized to predict the drying shrinkage of recycled concrete containing SAP. The results show that the strength and durability of concrete are decreased by the addition of recycled aggregate. With the increase of the dosage of SAP, the strength and durability also raise. The prediction GM (1, N) model for the drying shrinkage of recycled concrete with SAP is in good agreement with the actual drying shrinkage.
33
Kwon, Yong-Rok, Jung-Soo Kim, and Dong-Hyun Kim. "Effective Enhancement of Water Absorbency of Itaconic Acid Based-Superabsorbent Polymer via Tunable Surface—Crosslinking." Polymers 13, no. 16 (August 19, 2021): 2782. http://dx.doi.org/10.3390/polym13162782.
Full textAbstract:
A superabsorbent polymer (SAP) was synthesized by copolymerizing itaconic acid and vinyl sulfonic acid. The typically low absorbency of itaconic acid-based SAPs under mechanical loads was improved by introducing surface crosslinking. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize the synthesis and surface-crosslinking reactions in the SAP. Various conditions for surface-crosslinking reactions, such as the surface-crosslinking solution, content of surface-crosslinking agent, and reaction temperature, were explored and correlated with the gel strength and absorption characteristics of the resulting SAP particles. The distilled water content in the surface-crosslinking solution strongly influenced the absorption capacity of the SAP, but this sensitivity decreased when acetone was used as a co-solvent. Itaconic acid-based SAP that was crosslinked under optimal conditions exhibited centrifuge retention capacity and absorbency under a load of 31.1 and 20.2, respectively.
34
Liao, Renkuan, Wenyong Wu, Shumei Ren, and Peiling Yang. "Effects of Superabsorbent Polymers on the Hydraulic Parameters and Water Retention Properties of Soil." Journal of Nanomaterials 2016 (2016): 1–11. http://dx.doi.org/10.1155/2016/5403976.
Full textAbstract:
Superabsorbent polymers (SAPs) are widely applied in dryland agriculture. However, their functional property of repeated absorption and release of soil water exerts periodic effects on the hydraulic parameters and water-retention properties of soil, and as this property gradually diminishes with time, its effects tend to be unstable. During the 120-day continuous soil cultivation experiment described in this paper, horizontal soil column infiltration and high-speed centrifugation tests were conducted on SAP-treated soil to measure unsaturated diffusivityDand soil water characteristic curves. The experimental results suggest that the SAP increased the water retaining capacity of soil sections where the suction pressure was between 0 and 3,000 cm. The SAP significantly obstructed water diffusion in the soil in the early days of the experiment, but the effect gradually decreased in the later period. The average decrease in water diffusivity in the treatment groups fell from 76.6% at 0 days to 1.2% at 120 days. This research also provided parameters of time-varying functions that describe the unsaturated diffusivityDand unsaturated hydraulic conductivityKof soils under the effects of SAPs; in future research, these functions can be used to construct water movement models applicable to SAP-treated soil.
35
Yeon, Jung Heum. "Restrained Stress Development in Hardening Mortar Internally Cured with Superabsorbent Polymers under Autogenous and Drying Conditions." Polymers 13, no. 6 (March 23, 2021): 979. http://dx.doi.org/10.3390/polym13060979.
Full textAbstract:
This study reports the results of a series of experiments, particularly paying attention to the early-age behavior and response of hardening mortars incorporating different types and contents of superabsorbent polymer (SAP) under autogenous (sealed) and drying shrinkage (unsealed) conditions. To achieve this primary aim, the effects of SAP type (i.e., cross-linking density and grain size) and content on the internal relative humidity (IRH) changes and corresponding free shrinkage behavior, restrained stress development, and cracking potential of the mortar were extensively measured and analyzed, along with their strength and set time properties. The results of this study have shown that the internal curing (IC) via SAP effectively counteracted the early-age residual stress build-up due to autogenous shrinkage, as many other former studies described. No or little tensile residual stresses due to autogenous shrinkage took place when more than 0.4% SAP was added, regardless of the SAP type. However, it should be mentioned that the addition of SAP, irrespective of its content and type, hardly improved the shrinkage cracking resistance of the mortar when directly exposed to drying environment at early ages.
36
Kim, Semin, Minsu Kim, and Won-Gun Koh. "Preparation of Surface-Reinforced Superabsorbent Polymer Hydrogel Microspheres via Incorporation of In Situ Synthesized Silver Nanoparticles." Polymers 13, no. 6 (March 15, 2021): 902. http://dx.doi.org/10.3390/polym13060902.
Full textAbstract:
Superabsorbent polymer (SAP) particles are primarily applied for absorbing and storing liquids. Here, poly (acrylic acid) (PAA)-based SAP microspheres incorporated with silver nanoparticles (AgNPs) are prepared as an effort to maintain microsphere shape during swelling and minimize gel blocking. PAA-based SAP spheres are synthesized via inverse suspension polymerization. AgNPs are formed within SAP spheres through in situ reduction of silver nitrate (AgNO3), using polyvinylpyrrolidone as the reducing agent. The formation of AgNPs within SAP was observed via techniques such as scanning electron microscopy, ultraviolet-visible spectroscopy, thermogravimetric analysis, X-ray photoelectron spectroscopy and transmission electron microscopy. Energy dispersive spectroscopy analyses reveal that thin and dense layers of AgNPs are formed on the outer regions of the SAP spheres at higher concentrations of AgNO3. The water absorbency capacity decreases on increasing the amount of incorporated silver nanoparticles; however, it is comparable with that of commercially available surface-crosslinked SAP particles. Finally, micro-computerized tomography (micro-CT) study revealed that AgNP-incorporated SAP spheres maintained their shapes during swelling and exhibit higher void fractions in the packed gel bed, minimizing gel blocking and improving fluid permeability.
37
Xuan, Mei-Yu, Yi-Sheng Wang, Xiao-Yong Wang, Han-Seung Lee, and Seung-Jun Kwon. "Effect of Cement Types and Superabsorbent Polymers on the Properties of Sustainable Ultra-High-Performance Paste." Materials 14, no. 6 (March 18, 2021): 1497. http://dx.doi.org/10.3390/ma14061497.
Full textAbstract:
This study focuses on the effects of superabsorbent polymers (SAP) and belite-rich Portland cement (BPC) on the compressive strength, autogenous shrinkage (AS), and micro- and macroscopic performance of sustainable, ultra-high-performance paste (SUHPP). Several experimental studies were conducted, including compressive strength, AS, isothermal calorimetry, X-ray diffraction (XRD), thermogravimetric analysis (TGA), attenuated total reflectance (ATR)–Fourier-transform infrared spectroscopy (FTIR), ultra-sonic pulse velocity (UPV), and electrical resistivity. The following conclusions can be made based on the experimental results: (1) a small amount of SAP has a strength promotion effect during the first 3 days, while BPC can significantly improve the strength over the following 28 days. (2) SAP slows down the internal relative humidity reduction and effectively reduces the development of AS. BPC specimens show a lower AS than other specimens. The AS shows a linear relationship with the internal relative humidity. (3) Specimens with SAP possess higher cumulative hydration heat than control specimens. The slow hydration rate in the BPC effectively reduces the exothermic heat. (4) With the increase in SAP, the calcium hydroxide (CH) and combined water content increases, and SAP thus improves the effect on cement hydration. The contents of CH and combined water in BPC specimens are lower than those in the ordinary Portland cement (OPC) specimen. (5) All samples display rapid hydration of the cement in the first 3 days, with a high rate of UPV development. Strength is an exponential function of UPVs. (6) The electrical resistivity is reduced due to the increase in porosity caused by the release of water from SAP. From 3 to 28 days, BPC specimens show a greater increment in electrical resistivity than other specimens.
38
Fořt, Jan, Jiří Maděra, and Martin Mildner. "Mechanical parameters of cementitious materials with superabsorbent polymer admixture." MATEC Web of Conferences 282 (2019): 02063. http://dx.doi.org/10.1051/matecconf/201928202063.
Full textAbstract:
Concrete despite many performed studies still requires further research on material optimization towards its improvements. On this account the superabsorbent polymers can be viewed as very promising materials with a positive influence on various properties of cementitious materials. The beneficial effect of SAPs on mitigation of autogenous shrinkage or rapid cracks self-healing. However, the absorption capability of SAPs also poses a risk for the formation of dense structure and loss in material durability. The performed study contemplating the influence of two grades of SAP admixtures on mechanical parameters of designed concrete. Obtained results revealed an adverse effect of SAPs on compressive strength. This finding can be assigned to a rapid swelling capability of SAPs, thus a formation of voids in material structure and a significant increase in the total open porosity. Incorporation of about 1.5 wt.% of SAP admixture decreased compressive strength about almost 50% compared to the reference sample.
39
Awadallah-F, Ahmed, and Tahia B. Mostafa. "Synthesis and characterization studies of γ-radiation crosslinked poly(acrylic acid/2-acrylamido-2-methyl propane sulfonic acid) hydrogels." Journal of Polymer Engineering 34, no. 5 (July 1, 2014): 459–69. http://dx.doi.org/10.1515/polyeng-2013-0067.
Full textAbstract:
Abstract Superabsorbent polymer (SAP) hydrogels were synthesized by copolymerization of acrylic acid and 2-acrylamido-2-methyl propane sulfonic acid and their sodium salts. The effects of reaction variables were optimized. SAPs were treated with chemical reagents. The structures and the morphologies of untreated and treated SAP hydrogels were analyzed by different techniques. The swelling/deswelling kinetics of SAP hydrogels, pH and salt sensitivity were investigated. The results show that these samples imbibed about 4310±27 g/g in deionized water, 269±18 g/g in artificial blood and 288±11 g/g in artificial urine. The highest swelling, reversible pH-responsiveness and salt sensitivity of hydrogels widen their applications.
40
Kang, Sung-Hoon, Sung-Gul Hong, and Juhyuk Moon. "Absorption kinetics of superabsorbent polymers (SAP) in various cement-based solutions." Cement and Concrete Research 97 (July 2017): 73–83. http://dx.doi.org/10.1016/j.cemconres.2017.03.009.
Full text
41
Rostami, Rohollah, Agnieszka J. Klemm, and Fernando C. R. Almeida. "Reduction of shrinkage by Superabsorbent polymers (SAP) in fibre reinforced mortars." Construction and Building Materials 288 (June 2021): 123109. http://dx.doi.org/10.1016/j.conbuildmat.2021.123109.
Full text
42
Woyciechowski, Piotr, and Maciej Kalinowski. "The Influence of Dosing Method and Material Characteristics of Superabsorbent Polymers (SAP) on the Effectiveness of the Concrete Internal Curing." Materials 11, no. 9 (September 3, 2018): 1600. http://dx.doi.org/10.3390/ma11091600.
Full textAbstract:
This paper examines the influence of dosing method and material characteristic of superabsorbent polymers (SAP) used for internal curing, on the selected concrete properties. A new method of introducing SAP into the concrete mix and its impact on the shrinkage and compressive strength of concrete was studied. It was shown that the method of dosing SAP to the concrete mix and the differences in the properties of the tested SAPs have a significant impact on the course of changes of selected properties of the tested concrete composites. In order to compare tested series with each other and with other published results on the subject, a new method of including SAP mass content in the concrete mix, as a percentage of absorbed mixing water, was presented. The effectiveness of internal curing using different types of SAP under different dosing methods was presented as a percentage difference in tested concrete properties between modified series and reference series.
43
Sivri, Çağlar. "Improvement of protective and comfort properties of face masks using superabsorbent polymer containing nanofibers." International Journal of Clothing Science and Technology 30, no. 5 (September 3, 2018): 668–86. http://dx.doi.org/10.1108/ijcst-10-2017-0169.
Full textAbstract:
Purpose The purpose of this paper is to introduce a novel face mask prototype having a superabsorbent nanofibrous coating with a homogenous distribution. Design/methodology/approach Superabsorbent nanofibers were manufactured via electrospinning method using Poly(vinyl alcohol)/superabsorbent polymer (PVA/SAP) aqueous polymer solutions and they were simultaneously coated onto face masks in order to develop their virus protection and comfort properties. Absorbency, air permeability, Fourier Transform Infrared Spectroscopy (FT-IR) and SEM investigations were carried out for characterization. Findings SEM investigations revealed that face masks were homogenously coated with nanofibers. Picks obtained from FT-IR spectra proved that all mask samples have PVA/SAP content indicating their absorbent feature. Liquid absorption capacity and air permeability tests have shown that nanofiber coating increased the hydrophilicity of face masks while air permeability decreased in reverse. Final prototype has been found to be promising for industrial, scientific and medical applications with its improved protection and comfort characteristics. Research limitations/implications The implication of the research is to investigate the morphological, physical and transfer difference of face masks that are coated with nanofibers and uncoated face masks. This is useful in selection of the right face mask with optimum surface, absorbency and transfer properties. Originality/value Compared to commercial product in the market, the face mask developed within the study has a more regularly distributed nanofiber coating.
44
Che Ani, Norlirabiatuladawiyah, Saidatul Shima Jamari, and Wan Siti Nadiah Wan Yaacob. "Effect of Cross-Linker Concentration on the Synthesis and Swelling Behaviour of Superabsorbent Polymers (SAP) Using Graft Polymerization Techniques." Key Engineering Materials 719 (November 2016): 62–66. http://dx.doi.org/10.4028/www.scientific.net/kem.719.62.
Full textAbstract:
The graft polymerization of acrylic acid by varying the amount of cross-linker in ranging of 0.001 g to 0.05 g was investigated. The effect of cross-linker in synthesized superabsorbent polymers (SAP) was identified in terms of water absorbency responses by keeping the values of monomer and initiator. The implementation of SAP in agriculture could develop plant growth, enhancing water retention capacity in soils which can reducing dewatering system and improved the efficiency of soil condition so higher yield of product can be obtained particularly in arid regions. The SAPs were synthesized by graft polymerization using acrylic acid (AA) as monomer, N,N’-methylene bisacrylamide (MBA) as cross-linker and ammonium persulfate (APS) as initiator. The optimum water absorbency of synthesize SAP was defined using tea-bag method in deionize water. The structures of synthesize SAP was characterized by Fourier Transform Infrared Spectroscopy (FTIR) and morphologies of synthesize SAP was examined by Scanning Electron Microscope (SEM) testing. From the result, it was obvious showed that water absorbency will decreased as the increased of concentration of cross-linker which is MBA in synthesize SAP. The best value content of MBA was 0.01 g which achieved the highest water absorbency response which is 170 g water/g sample. In conclusion, SAP has hydrophilic structure of which renders them capable for holding a large amount of water which can help to retain nutrients and absorb water in soil with various applications for plant growth and soil condition which will be useful especially in agriculture field.
45
Kalinowski, Maciej, and Piotr Woyciechowski. "Chloride Diffusion in Concrete Modified with Polyacrylic Superabsorbent Polymer (SAP) Hydrogel—The Influence of the Water-to-Cement Ratio and SAP-Entrained Water." Materials 14, no. 15 (July 21, 2021): 4064. http://dx.doi.org/10.3390/ma14154064.
Full textAbstract:
This paper examines the influence of polyacrylic superabsorbent polymers (SAP) on the properties concerning chloride diffusion in cementitious materials. The conducted study investigated the influence of SAP on chloride diffusion in concretes of the initial w/c = 0.4 (for which the changes in compressive strength due to the SAP presence were negligible). The impact on the diffusivity of concrete of several variables was analyzed: the material characteristics of SAP, additional water added to the concrete to make up for the amount of water stored in the SAP structure, and the method of SAP dosing to the mix (either in a non-saturated form or in a hydrogel form). We found that, in the case of modifying concrete with polyacrylic SAP of a median particle size in dry conditions of 330 µm and without additional water, the coefficient of chloride ion diffusion was reduced to 65% of the reference value. The negative influence (increase) of increasing w/ctot by the amount of water initially entrained by SAP on the chloride diffusivity of concrete was identified. The conducted study indicates the premise of the mechanism of the water release from SAP in cementitious composites.
46
Snoeck, Didier. "Superabsorbent polymers to seal and heal cracks in cementitious materials." RILEM Technical Letters 3 (November 15, 2018): 32–38. http://dx.doi.org/10.21809/rilemtechlett.2018.64.
Full textAbstract:
Superabsorbent polymers (SAPs) are promising admixtures to improve properties in cementitious materials. Not only useful to mitigate autogenous shrinkage and to increase the freeze-thaw resistance, SAP particles may enhance self-sealing and self-healing in cementitious materials. The self-sealing leads to a regain in water tightness and promoted autogenous healing may prove to be useful to limit repair works caused by concrete cracking. By providing sufficient building blocks for healing, limiting the crack width by means of synthetic microfibers and inducing water by means of SAPs, a smart cementitious material is obtained. This material can be an excellent material to use in future building applications such as tunnel works and ground-retaining structures. This paper gives an overview of the current status of the research on SAPs in cementitious materials to obtain sealing and healing.
47
Almeida, Fernando C. R., and Agnieszka J. Klemm. "Efficiency of internal curing by superabsorbent polymers (SAP) in PC-GGBS mortars." Cement and Concrete Composites 88 (April 2018): 41–51. http://dx.doi.org/10.1016/j.cemconcomp.2018.01.002.
Full text
48
Khattab, Mustafa M., Sameh Badry Tobeia, and Mouhammed Jessam Lafta. "The effects of different polymer materials on concrete properties containing superabsorbent polymers (SAP)-experimental study." IOP Conference Series: Materials Science and Engineering 737 (March 6, 2020): 012053. http://dx.doi.org/10.1088/1757-899x/737/1/012053.
Full text
49
Olawuyi, Babatunde James, and William Peter Boshoff. "Influence of superabsorbent polymer on the splitting tensile strength and fracture energy of high-performance concrete." MATEC Web of Conferences 199 (2018): 11004. http://dx.doi.org/10.1051/matecconf/201819911004.
Full textAbstract:
Superabsorbent polymers (SAP) addition as an internal curing (IC) agent in concrete is an approach being adopted for the mitigation of autogenous shrinkage. Micro-voids created by SAP are arguably believed to be detrimental to the mechanical properties especially the fracture tendencies of the concrete. This paper presents the report of an experimental study of SAP’s influence on the splitting tensile strength and fracture energy of low water/binder (W/B) high-performance concrete (HPC). Reference HPC mixtures (M1F, M1S, M2 and M3) designed for a 28-day minimum cube compressive strength of 70 N/mm2 (MPa) were examined for the effect of SAP grain size, content and binder type on the above stated properties. Wedge splitting test was carried out on 100 mm cube specimen of HPC containing varied SAP contents (0.2, 0.3 and 0.4 by weight of binder (bwob)) and SAP sizes, cured by water immersion for 28, 56 and 90 days respectively. The results obtained was plotted as splitting force (Fsp in kN) against the crack mouth opening displacement (CMOD in mm) for computing the work of fracture (Wf), which is the area under the Fsp CMOD curve. The study concludes that the splitting tensile strength and fracture energy of the HPCs are not directly affected by SAP addition (i.e. neither grain size nor content).
50
Farzanian, Khashayar, Babak Vafaei, and Ali Ghahremaninezhad. "The Behavior of Superabsorbent Polymers (SAPs) in Cement Mixtures with Glass Powders as Supplementary Cementitious Materials." Materials 12, no. 21 (November 1, 2019): 3597. http://dx.doi.org/10.3390/ma12213597.
Full textAbstract:
The absorption and desorption of superabsorbent polymers (SAPs) in cement mixtures containing two different glass powders as supplementary cementitious materials are examined in this paper. Two SAPs with different chemical compositions were synthesized in-house and used in the experiments. SAP absorption was investigated directly through the mass change of SAPs in cement slurries, as well as indirectly using the flow test. Scanning electron microscopy was used to monitor the desorption of SAPs using samples prepared with freeze-drying. Hydration and setting time were evaluated to explain the desorption behavior of SAPs. SAP absorption generally increased in pastes with glass powders. The desorption rate of SAPs in different pastes was shown to correlate with the onset of solid skeleton development in the pastes. The addition of SAPs reduced autogenous shrinkage in neat cement paste more than in pastes with glass powders.