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Journal articles on the topic 'Hydrophobic polymer'

Author: Grafiati

Published: 7 June 2025

Last updated: 17 July 2025

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Su, Ziyang, Yu Zhang, Weidong Liu, et al. "A Quantitative Approach to Determine Hydrophobe Content of Associating Polyacrylamide Using a Fluorescent Probe." Molecules 28, no. 10 (2023): 4152. http://dx.doi.org/10.3390/molecules28104152.

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Hydrophobically associating polymers have found widespread applications in many domains due to their unique rheological behavior, which is primarily dictated by the hydrophobe content. However, the low fraction of hydrophobic monomers in polymers makes this parameter’s precise and straightforward measurement difficult. Herein, a variety of hydrophobically associating polyacrylamides (HAPAM) with different alkyl chain lengths (L) and hydrophobic contents ([H]) were prepared by post-modification and accurately characterized by 1H NMR spectroscopy. The maximal fluorescence emission intensity (I) of 8-anilino-1-naphthalenesulfonic acid, which is sensitive to hydrophobic environments, was then detected in those polymer solutions and shown as a ratio to that in the polymer-free solution (I0). It was found that I/I0 for 0.5 wt% HAPAM can be scaled versus CH, which is a variate related to both L and [H], as I/I0 = 1.15 + 1.09 × 108CH3.42, which was also verified to be applicable for hydrophobic associating hydrolyzed polyacrylamide (HHAPAM). This relationship provides a handy method for determining the hydrophobic content of hydrophobically associating polymers, particularly for field applications.

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Carro, Shirley, Valeria J. Gonzalez-Coronel, Jorge Castillo-Tejas, Hortensia Maldonado-Textle, and Nancy Tepale. "Rheological Properties in Aqueous Solution for Hydrophobically Modified Polyacrylamides Prepared in Inverse Emulsion Polymerization." International Journal of Polymer Science 2017 (2017): 1–13. http://dx.doi.org/10.1155/2017/8236870.

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Inverse emulsion polymerization technique was employed to synthesize hydrophobically modified polyacrylamide polymers with hydrophobe contents near to feed composition. Three different structures were obtained: multisticker, telechelic, and combined. N-Dimethyl-acrylamide (DMAM), n-dodecylacrylamide (DAM), and n-hexadecylacrylamide (HDAM) were used as hydrophobic comonomers. The effect of the hydrophobe length of comonomer, the initial monomer, and surfactant concentrations on shear viscosity was studied. Results show that the molecular weight of copolymer increases with initial monomer concentration and by increasing emulsifier concentration it remained almost constant. Shear viscosity measurements results show that the length of the hydrophobic comonomer augments the hydrophobic interactions causing an increase in viscosity and that the polymer thickening ability is higher for combined polymers.

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Shi, Lei Ting, Zhe Na Shen, Wei Zhou, Zhong Bin Ye, and Jun Feng Wang. "Study on the Performance of Hydrophobic Association Water-Soluble Polymer with Strong Association Ability." Advanced Materials Research 418-420 (December 2011): 232–36. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.232.

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In this article, the viscosifying abilities, rheological properties, and flow characteristics of hydrophobic association water-soluble polymer with high association ability were studied using technical methods of viscosity measurement, rheological and core flow experiments. The results illustrate that hydrophobic associated polymers with low molecular weight rely on a strong hydrophobic interaction, the intermolecular and intramolecular micellar structure formed in solution with a strong ability to increase viscosity. Hydrophobic association water-soluble polymer, comparing with partially hydrolyzed polyacrylamides polymer with low molecular weight, presents a better ability of shear stability under the condition of shearing and the solution structure strengthens gradually so as to increase viscoelasticity remarkably. The hydrophobic association water-soluble polymer with high association ability take on greater injectivity and mobility control ability in low permeability porous media solving the problem of low injectivity and poor control ability in mid-low permeability reservoirs, which improves polymers flooding effect in such reservoirs and underlie the reasonable design of polymer molecular structure.

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Ebdon, J. R., B. J. Hunt, D. M. Lucas, I. Soutar, L. Swanson, and A. R. Lane. "Luminescence studies of hydrophobically modified, water-soluble polymers. I. Fluorescence anisotropy and spectroscopic investigations of the conformational behaviour of copolymers of acrylic acid and styrene or methyl methacrylate." Canadian Journal of Chemistry 73, no. 11 (1995): 1982–94. http://dx.doi.org/10.1139/v95-245.

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Fluorescence spectroscopy and anisotropy measurements have been used to study a series of styrene – acrylic acid, STY–AA, and methyl methacrylate – acrylic acid, MMA–AA, copolymers in dilute methanolic and aqueous solutions. Copolymerization of either STY or MMA with AA has little effect upon the rate of intramolecular segmental motion in methanol solutions. In aqueous media, intramolecular hydrophobic aggregation occurs and restricts the macromolecular dynamics to an extent dependent upon pH, nature of the comonomer, and copolymer composition. The hydrophobic domains formed in these copolymer systems can solubilize organic guests. In this respect, STY is a more powerful modifier of AA-based polymer behaviours than is MMA. In general, the hydrophobic modification increases the solubilization power of the resultant polymer. Furthermore, the copolymers retain their solubilization capacities to higher values of pH the more hydrophobic the comonomer and the greater its content in the copolymer. The interiors of the hydrophobic aggregates reduce the mobilities of occluded guests: the microviscosities of the domain interiors depend upon the nature of the hydrophobe, pH, and copolymer composition. Keywords: fluorescence, anisotropy, water-soluble polymers, acrylic acid, hydrophobic modification.

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Xiang, Dingding, Kanglian Liu, Dawang Wu, Jing Zhou, Maoqi Cao, and Haili Mao. "Study on hydrophobic properties of coatings enhanced by organofluorosilicone polymers." Journal of Physics: Conference Series 2342, no. 1 (2022): 012012. http://dx.doi.org/10.1088/1742-6596/2342/1/012012.

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Abstract Hydrophobic materials are widely used in industry and life. It is of great practical significance to develop new hydrophobic materials. In this paper, organofluorosilicone polymers were prepared by low-cost and easily accessible process using organofluorosilicone prepolymers as reactants and under the action of organosilicon crosslinking agent. Infrared spectrum test showed that the prepared organofluorosilicone polymer had obvious C-F stretching vibration peak at 1211cm-1, which proved the effective synthesis of organofluorosilicone polymer. The test of contact Angle under water condition shows that the water contact Angle of coating materials added with organofluorosilicone polymer is larger. Therefore, organofluorosilicone polymer can be used as a kind of efficient hydrophobic additive to enhance the hydrophobicity of coating materials.

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Park, KeumHwan, Cheolmin Shin, Ye-Seul Song, Hee-Jin Lee, Chiho Shin, and Youngmin Kim. "Recyclable and Mendable Cellulose-Reinforced Composites Crosslinked with Diels–Alder Adducts." Polymers 11, no. 1 (2019): 117. http://dx.doi.org/10.3390/polym11010117.

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Owing to their natural abundance and exceptional mechanical properties, cellulose fibers (CFs) have been used for reinforcing polymers. Despite these merits, dispersing hydrophilic CFs in a hydrophobic polymer matrix is challenging. To address this, an amphiphilic ammonium salt was employed as the dispersant for CFs in this study. The hydrophobic CFs were mixed with a healable polymer to produce CF-reinforced composites. As the thermosetting polymer was crosslinked with Diels–Alder (DA) adducts, it was mended and recycled via a retro DA reaction at 120 °C. Interestingly, the CF-reinforced polymer composites were mended and recycled as well. When 5 wt % of the hydrophobic CFs was added to the polymer, maximum tensile strength, elongation at break, Young’s modulus, and toughness increased by 70%, 183%, 75%, and 420%, respectively. After recycling, the CF-reinforced composites still featured better mechanical properties than recycled polymer.

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Yamakita, Yoshihiro, Issei Takeuchi, Kimiko Makino, Hiroshi Terada, Akihiko Kikuchi, and Kolio Troev. "Thermoresponsive Polyphosphoester via Polycondensation Reactions: Synthesis, Characterization, and Self-Assembly." Molecules 27, no. 18 (2022): 6006. http://dx.doi.org/10.3390/molecules27186006.

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Using a novel strategy, amphiphilic polyphosphoesters based on poly(oxyethylene H-phosphonate)s (POEHP) with different poly(ethylene glycol) segment lengths and aliphatic alcohols with various alkyl chain lengths were synthesized using polycondensation reactions. They were characterized by 1H NMR, 13C {H} NMR 31P NMR, IR, and size exclusion chromatography (SEC). The effects of the polymer structure on micelle formation and stability, micelle size, and critical micelle temperature were studied via dynamic light scattering (DLS). The hydrophilic/hydrophobic balance of these polymers can be controlled by changing the chain lengths of hydrophilic PEG and hydrophobic alcohols. A solubilizing test, using Sudan III, revealed that hydrophobic substances can be incorporated inside the hydrophobic core of polymer associates. Loading capacity depends on the length of alkyl side chains. The results obtained indicate that these structurally flexible polymers have the potential as drug carriers.

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Barmar, M., and B. Kaffashi. "Rheological Behavior of HEUR Mixtures in Aqueous Media." International Polymer Processing 22, no. 2 (2007): 146–50. http://dx.doi.org/10.1515/ipp-2007-0004.

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Abstract Three S-G HEUR thickeners were synthesized by a step growth polymerization technique of poly (ethylene oxide) (PEO) and dicyclohexylmethane – 4,40-diisocyanate (H12MDI) and then end capped with two monofunctional aliphatic alcohols. These polymers were mixed together according to the hydrophilic and hydrophobic nature of their segments. Based on this, two sets of associating polymers were introduced. In one set, the samples had identical hydrophobic segments while in the other one, hydrophilic segments were similar. The steady shear viscosity profiles of aqueous solutions of all models were determined. In addition, aqueous binary mixtures with various ratios of the S-G HEUR models were studied using steady state and dynamic rheometry. It is suggested that combinations of associating polymers with different size of hydrophobic segments and similar hydrophilic segments produce an associative polymer-like behavior. However, the combination of those with similar long hydrophobic segments and different hydrophilic segments at similar weight ratio in solution falls short of displaying an associative polymer – like behavior.

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Pavlov, Georges M., Anna A. Gosteva, Olga V. Okatova, Olga A. Dommes, Irina I. Gavrilova, and Evgenii F. Panarin. "Detection and evaluation of polymer–polymer interactions in dilute solutions of associating polymers." Polymer Chemistry 12, no. 15 (2021): 2325–34. http://dx.doi.org/10.1039/d0py01725f.

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Lee, Seunghyun, Hyejin Lee, Tae-Hyun Yang, et al. "Quaternary Ammonium-Bearing Perfluorinated Polymers for Anion Exchange Membrane Applications." Membranes 10, no. 11 (2020): 306. http://dx.doi.org/10.3390/membranes10110306.

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Perfluorinated polymers are widely used in polymer electrolyte membranes because of their excellent ion conductivity, which are attributed to the well-defined morphologies resulting from their extremely hydrophobic main-chains and flexible hydrophilic side-chains. Perfluorinated polymers containing quaternary ammonium groups were prepared from Nafion- and Aquivion-based sulfonyl fluoride precursors by the Menshutkin reaction to give anion exchange membranes. Perfluorinated polymers tend to exhibit poor solubility in organic solvents; however, clear polymer dispersions and transparent membranes were successfully prepared using N-methyl-2-pyrrolidone at high temperatures and pressures. Both perfluorinated polymer-based membranes exhibited distinct hydrophilic-hydrophobic phase-separated morphologies, resulting in high ion conductivity despite their low ion exchange capacities and limited water uptake properties. Moreover, it was found that the capacitive deionization performances and stabilities of the perfluorinated polymer membranes were superior to those of the commercial Fumatech membrane.

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K., Rekha Rani* Y. Navya Reddy R. Mohana Priya. "FORMULATION AND EVALUATION OF SUSTAINED RELEASE DOSAGE FORM OF KETOPROFEN." indo American Journal of Pharmaceutical Sciences 04, no. 05 (2017): 1384–90. https://doi.org/10.5281/zenodo.804916.

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Sustained release Ketoprofen matrix tablets were prepared by direct compression method. The nature of the polymer influences the physical and release characteristics of the matrix tablet. The hydrophobic polymer, Ethyl cellulose has retarded the drug release from the tablet and the hydrophilic polymer, HPMC (15 cps) has release the drug. While making the combination of both hydrophilic and hydrophobic polymers i.e HPMC and Ethylcellulose with optimized ratio (F7) leads to sustained release of drug from matrix tablet for 12 hours was observed Key words: Ketoprofen, HPMC (15 cps), Ethyl cellulose

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Feizi, Froozan, Mojtaba Shamsipur, Mohammad Bagher Gholivand, et al. "Harnessing the enantiomeric recognition ability of hydrophobic polymers of intrinsic microporosity (PIM-1) toward amino acids by converting them into hydrophilic polymer dots." Journal of Materials Chemistry C 8, no. 39 (2020): 13827–35. http://dx.doi.org/10.1039/d0tc03138k.

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In this work, we synthesized novel polymer dots (Pdots) from polymers of intrinsic microporosity (PIM-1) containing a racemic mixture of R- and S-chiral centers as the hydrophobic conjugated polymer chains.

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Ruckenstein, Eli, and Jun Seo Park. "Hydrophilic-hydrophobic polymer composites." Journal of Polymer Science: Polymer Letters Edition 26, no. 12 (1988): 529–36. http://dx.doi.org/10.1002/pol.1988.140261207.

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Rikhia, Ghosh, Roy Susmita, and Bagchi Biman. "Fluctuation quench and hydrophobic collapse of polymers and biopolymers water-DMSO binary mixture at low DMSO concentration." Journal of Indian Chemical Society Vol. 88, Aug 2011 (2011): 1223–31. https://doi.org/10.5281/zenodo.5786101.

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SSCU, Indian Institute of Science, Bangalore-560 012, India E-mail : bbagchi@sscu. iisc.ernet. in; http/lliquid.sscu.iisc.ernet.in Manuscript received 17 June 2011, accepted 20 June 2011 Binary mixtures have strong influence on activities of polymers and biopolymers even at low cosolvent concentration. Among the several aqueous binary mixtures studied, water-DMSO especially stands out for its unusual behavior at certain specific concentrations of DMSO. In the present work, we study the effect of water-DMSO binary mixture on polymers and biopolymers by taking a simple linear hydrocarbon chain of intermediate length (n = 30) and the protein lysozyme, respectively. We find that at a mole fraction of 0.05 of DMSO (ᵪDMSO = 0.05) in aqueous solution, the hydrocarbon chain adopts the collapsed conformation as the most stable and rigid state. In this case of 0.05 mole fraction of DMSO in bulk, the DMSO concentration in the first hydration layer around the polymer is found to be as large as 17%. Formation of such hydrophobic environment around the polymer is the reason for the collapsed state gaining so much stability. Interestingly, similar quench of conformational fluctuation is also observed for the protein investigated. It is observed that in the case of alkane polymer chains, long wavelength fluctuation gets easily quenched, the polymer being purely hydrophobic. However, in case of the protein, quench of fluctuation is prominent only at the hydrophobic surface, and quench of long wavelength fluctuation becomes insignificant for the full protein. As protein contains both hydrophobic and hydrophilic moieties, the extent of quench of conformational fluctuation with respect to that in pure water is almost half for the biopolymer complex (16.83%) than the same for pure hydrophobic polymer chain (32.43%).

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Kim, Jinyoung, Choong-Jae Lee, Dong-Gun Lee, et al. "Controlling the Dissolution Behavior of (Meth)acrylate-Based Photoresist Polymers in Tetramethylammonium Hydroxide by Introducing Adamantyl Groups." Materials 18, no. 2 (2025): 381. https://doi.org/10.3390/ma18020381.

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(Meth)acrylate polymers are commonly used as photoresist materials in photolithography. However, these polymers encounter the problem of swelling during the development process. To address this, we explored the use of a hydrophobic group to control the solubility in the hydrophilic developer. In this study, we synthesized two types of polymers to evaluate the impact of the developer on (meth)acrylate polymers for photoresist applications. Adamantyl methacrylate (AdMA) was selected as the hydrophobic group, while 2-ethoxyethyl acrylate (2-EEA) served as the hydrophilic group, enabling the synthesis of both hydrophilic and hydrophobic polymers. Our goal was to assess how the presence of adamantyl monomers influenced the solubility of the polymer. This study demonstrated that solubility was primarily influenced by functional groups, particularly hydrophobic groups, rather than other factors. Polymers with more than 50% hydrophobic groups can be effectively controlled for their solubility in TMAH. These findings show that the solubility of photoresist polymers in TMAH can be tuned by incorporating a high proportion of hydrophobic groups. The study further confirms the role of adamantyl monomers as effective hydrophobic (aliphatic) groups in modulating the solubility of (meth)acrylate polymers in developer solutions.

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Cheng, Xi Tao, Wen Hong Li, Cun She Zhang, and Yan Bai. "Synthesis and Application of Fluorosilicone Polymer." Advanced Materials Research 900 (February 2014): 365–77. http://dx.doi.org/10.4028/www.scientific.net/amr.900.365.

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The structure, properties, synthesis methods and application of siloxane fluorinated polyacrylate polymers,side chain fluorinated silicone polymer and fluoro-silicone block copolymers are discussed. Fluorosilicone polymers has excellent physical property such as low and high temperature resistance, hydrophobic oleophobic property, lubricity etc. It is an advanced material.

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Feng, Liandong, Xinyu Hu, Aming Xie, et al. "Cationic Charged Polymer Vesicles from Amphiphilic PEI-g-PSSA-g-PEI as Potential Gene Delivery Vehicles." Australian Journal of Chemistry 68, no. 5 (2015): 806. http://dx.doi.org/10.1071/ch14350.

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Polymer vesicles have attracted extensive interest for a variety of biomedical applications. Herein, novel polymer vesicles are prepared by the self-assembly of amphiphilic polyethyleneimine-g-poly(disulfide amine)-g-polyethyleneimine (PEI-g-PSSA-g-PEI) for gene delivery. To investigate the effect of hydrophobicity on transfection efficiency, a small series of PEI-g-PSSA-g-PEI were prepared under uniform conditions containing PEI fragments of the same molecular weight. The hydrophobicity of PEI-g-PSSA-g-PEI was adjusted by varying the hydrophobic content in the poly(disulfide amine) backbone and by choosing hydrophobic monomers ranging in length from C12 to C16. The hydrophobicity of polymers was also related to DNA binding affinity. Polymer vesicles obtained from the water-insoluble polymers condensed with DNA into polyplexes with sizes below 200 nm and surface charge ranging from +10 to +35 mV that were suitable for cell endocytosis. DNA polyplexes exhibited an inverted hexagonal structure, observed by transmission electron microscopy. The results of in vitro transfection demonstrate that the hydrophobic–hydrophilic balance of copolymers greatly affects their transfection properties. The top-performing polymer, II-70 %, showed improved transfection efficiency and significantly lower cytotoxicity on COS-7 cells when compared with commercial reagents polyethyleneimine (PEI 25K) and Lipofectamine 2000. These results indicate that cationic polymer vesicles with tunable hydrophobicity are promising materials for gene delivery.

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Wen, Xin, Lei Wang, Xiaojuan Lai, et al. "Polymerization Behavior and Rheological Properties of a Surfactant-Modified Reactive Hydrophobic Monomer." Chemistry 5, no. 4 (2023): 2598–612. http://dx.doi.org/10.3390/chemistry5040168.

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The structures and properties of hydrophobic association polymers can be controlled using micelles. In this work, we synthesize a reactive hydrophobic surfactant monomer, KS-3, from oleic acid, N,N-dimethylpropylenediamine, and allyl chloride. A strong synergistic effect between KS-3 and cocamidopropyl betaine in aqueous solution enhances the hydrophilic dispersibility of KS-3, thereby transforming spherical micelles into cylindrical micelles. KS-3 was grafted onto a polyacrylamide chain via aqueous free-radical polymerization to obtain RES, a hydrophobic association polymer. Structural analysis revealed that the RES polymers assembled in wormlike micelles were more tightly arranged than those assembled in spherical micelles, resulting in a compact network structure in water, smooth surface, and high thermal stability. Rheological tests revealed that the synthesized polymers with wormlike and spherical micelles exhibited shear-thinning properties along with different structural strengths and viscoelasticities. Therefore, controlling the micellar state can effectively regulate the polymer properties. The polymers obtained through wormlike micelle polymerization have potential applications in fields with high demands, such as drug release, water purification, and oilfield development.

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Wahyuningsih, Sayekti, Rochmad E. Cahyono, and Fitri N. Aini. "Preparation Titanium Dioxide Combined Hydrophobic Polymer with Photocatalytic Self-Cleaning Properties." Bulletin of Chemical Reaction Engineering & Catalysis 15, no. 3 (2020): 874–84. http://dx.doi.org/10.9767/bcrec.15.3.9225.874-884.

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Titanium dioxide (TiO2) and hydrophobic of TiO2/PDMS (PDMS = polydimethylsiloxane) have been prepared as photocatalytic self-cleaning materials. Synthesis of TiO2 was carried out using the sol-gel method with titanium(IV) isopropoxide (TTIP) as a precursor and acetic acid as a solvent at a temperature of about 10–15 °C, while the synthesis of hydrophobic of TiO2/PDMS composites was carried out by a sonication method under ethanol solution. The results of XRD analysis of synthesized TiO2 showed that TiO2 was anatase phase. The glass-coated TiO2/PDMS were prepared by dip-coating under an ultrasonication bath. TiO2/PDMS composites at a ratio of TiO2/PDMS (1) on the glass plate showed hydrophobic properties, as evidenced by the contact angle of 104° before irradiation and the contact angle of 99.7° after irradiation. The synthesized titanium dioxide has irregular spherical morphology. The increase in PDMS content was correlated with an increase in the roughness of TiO2. PDMS not only acts as low surface energy but also binds TiO2. The hydrophobic behavior of PDMS creates TiO2/PDMS repel each other, gain irregular agglomeration structures. Beside having optimum contact angle, glass-coated TiO2/PDMS (1) is the best composition for degradation of methylene blue in 69.68% for 20 minutes irradiation. Copyright © 2020 BCREC Group. All rights reserved

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Tanaka, Takumi, Yuki Terauchi, Akira Yoshimi, and Keietsu Abe. "Aspergillus Hydrophobins: Physicochemical Properties, Biochemical Properties, and Functions in Solid Polymer Degradation." Microorganisms 10, no. 8 (2022): 1498. http://dx.doi.org/10.3390/microorganisms10081498.

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Hydrophobins are small amphipathic proteins conserved in filamentous fungi. In this review, the properties and functions of Aspergillus hydrophobins are comprehensively discussed on the basis of recent findings. Multiple Aspergillus hydrophobins have been identified and categorized in conventional class I and two non-conventional classes. Some Aspergillus hydrophobins can be purified in a water phase without organic solvents. Class I hydrophobins of Aspergilli self-assemble to form amphipathic membranes. At the air–liquid interface, RolA of Aspergillus oryzae self-assembles via four stages, and its self-assembled films consist of two layers, a rodlet membrane facing air and rod-like structures facing liquid. The self-assembly depends mainly on hydrophobin conformation and solution pH. Cys4–Cys5 and Cys7–Cys8 loops, disulfide bonds, and conserved Cys residues of RodA-like hydrophobins are necessary for self-assembly at the interface and for adsorption to solid surfaces. AfRodA helps Aspergillus fumigatus to evade recognition by the host immune system. RodA-like hydrophobins recruit cutinases to promote the hydrolysis of aliphatic polyesters. This mechanism appears to be conserved in Aspergillus and other filamentous fungi, and may be beneficial for their growth. Aspergilli produce various small secreted proteins (SSPs) including hydrophobins, hydrophobic surface–binding proteins, and effector proteins. Aspergilli may use a wide variety of SSPs to decompose solid polymers.

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Gorgol, Marek, Agnieszka Kierys, and Radosław Zaleski. "Positron Lifetime Annihilation Study of Porous Composites and Silicas Synthesized Using Polymer Templates." Defect and Diffusion Forum 373 (March 2017): 280–83. http://dx.doi.org/10.4028/www.scientific.net/ddf.373.280.

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The porous structure of polymer-silica composites, based on three polymer templates, which differ in a porosity and hydrophobicity, was examined using positron annihilation lifetime spectroscopy. Additionally, the investigation of silicas obtained after removal of polymers during calcination of composite materials, was performed. In composites based on hydrophobic polymers, silica condensates only in larger free volumes, while SiO2 deeply penetrates spaces between polymer chains, when the template is polar. Moreover, the structure of the silica gel, obtained after polymer removal, depends on chemical character of the template, rather than its porosity.

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Xia, Xiujian, Jintang Guo, Yakai Feng, et al. "Hydrophobic associated polymer “grafted onto” nanosilica as a multi-functional fluid loss agent for oil well cement under ultrahigh temperature." RSC Advances 6, no. 94 (2016): 91728–40. http://dx.doi.org/10.1039/c6ra12618a.

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In this study, a novel hydrophobic associated polymer/nanosilica composite with a micro-crosslinking structure was synthesized to address the drawbacks of traditional polymers in ultrahigh temperature performance.

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Ishihara, Kazuhiko, Shohei Hachiya, Yuuki Inoue, Kyoko Fukazawa, and Tomohiro Konno. "Water-Soluble and Cytocompatible Phospholipid Polymers for Molecular Complexation to Enhance Biomolecule Transportation to Cells In Vitro." Polymers 12, no. 8 (2020): 1762. http://dx.doi.org/10.3390/polym12081762.

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Water-soluble and cytocompatible polymers were investigated to enhance a transporting efficiency of biomolecules into cells in vitro. The polymers composed of a 2-methacryloyloxyethyl phosphorylcholine (MPC) unit, a hydrophobic monomer unit, and a cationic monomer unit bearing an amino group were synthesized for complexation with model biomolecules, siRNA. The cationic MPC polymer was shown to interact with both siRNA and the cell membrane and was successively transported siRNA into cells. When introducing 20–50 mol% hydrophobic units into the cationic MPC polymer, transport of siRNA into cells. The MPC units (10–20 mol%) in the cationic MPC polymer were able to impart cytocompatibility, while maintaining interaction with siRNA and the cell membrane. The level of gene suppression of the siRNA/MPC polymer complex was evaluated in vitro and it was as the same level as that of a conventional siRNA transfection reagent, whereas its cytotoxicity was significantly lower. We concluded that these cytocompatible MPC polymers may be promising complexation reagent for introducing biomolecules into cells, with the potential to contribute to future fields of biotechnology, such as in vitro evaluation of gene functionality, and the production of engineered cells with biological functions.

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Kou, Zongliang, Detian Dou, Jiayi Zhu, et al. "Release Mechanism and pH Responsiveness of Starch-Based Polymers." Nano 14, no. 11 (2019): 1950145. http://dx.doi.org/10.1142/s1793292019501455.

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Amphiphilic polymer carriers (PEG–St–[Formula: see text]) were prepared from cassava starch and their pH response was investigated. First, hydrophobic tapioca starch polymer (St–[Formula: see text]) was prepared with octyl acyl as the hydrophobic group. The hydrophilic group polyethylene glycol (mPEG) was then introduced into the polymer by esterification to produce amphiphilic tapioca starch polymer (PEG–St–[Formula: see text]). Its self-assembly behavior was characterized using fluorescent probes. The morphology of PEG–St–[Formula: see text] was investigated by transmission electron microscopy (TEM). Loading of the anti-cancer drug curcumin was used to assess the delivery and slow-release performance of the amphiphilic tapioca starch polymer. Cumulative drug release was explored at various pH conditions, with the greatest release from drug-loaded micelles being observed under acidic conditions and stable in a neutral environment. These results provide a theoretical basis for the preparation of pH-responsive nanomicelle carriers, and a platform for the preparation of novel amphiphilic starch-based polymers.

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Shi, Lei Ting, Xiao Nan Li, Wei Zhou, et al. "Study on Properties of Pectinate Hydrophobically Associating Polyacrylamide Solutions." Advanced Materials Research 361-363 (October 2011): 526–29. http://dx.doi.org/10.4028/www.scientific.net/amr.361-363.526.

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In this article, the viscosifying abilities, rheological properties, flow characteristics of pectinate hydrophobically associating polymer (PHAP) solutions with different hydrophobe content were studied using technical methods of viscosity measurement, rheological and core flow experiments. Researches on viscosifying of different PHAPs at 20°C and 65°C in distilled water and saline indicate that, with the raise of hydrophobe content, viscosity of polymer solutions increases first and then decreases, which means that there should be a critical hydrophobe content( CHC). Below CHC, the anti-shear ability of polymer solutions enhances as hydrophobe content rises; while the shear resistance would fall down when and after the content reaches CHC. In high permeability porous media, all polymer solutions take on greater injectivity, and RFF can all be higher than 5, yet with the increasing of hydrophobe content, RF goes up first and then declines. It could be an effective way to enhance mobility control ability, improve polymer flooding effect in high permeability reservoirs and design polymer molecular structure more reasonably, using the pectinate structure and hydrophobic association interaction between polymer moleculars.

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Chee, Tan Yong, Abdull Rahim Mohd Yusoff, and Nik Ahmad Nizam Nik Malek. "Characterisation of poly(vinyl alcohol)- polycaprolactone hybridized scaffold for potential skin tissue regeneration." Malaysian Journal of Fundamental and Applied Sciences 16, no. 1 (2020): 6–9. http://dx.doi.org/10.11113/mjfas.v16n1.1469.

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The fabrication of a hybridized scaffold constituting hydrophobic and hydrophilic polymers for tissue engineering has received an increasing attention recently. Due to the high compatibility with water, a hydrophilic polymer, though is able to enhance cell affinity and proliferation, has a very high biodegradable rate and low stability in aqueous medium that eventually puncture its biomedical applications. Thereby, the addition of a hydrophobic polymer in the hydrophilic polymer scaffold is recommended to increase the hydrophobic property of the scaffold in order to reduce the limitation. Nonetheless, the fabrication of the hybridized scaffold is extremely challenging because the hydrophilic and the hydrophobic polymer tends to dissolve in different types of solvents, i.e. water and organic solvent, respectively, that subsequently restricts their blending process. In this work, a poly(vinyl alcohol) (PVA) scaffold, a polycaprolactone (PCL) scaffold, and their hybridized scaffold were produced through casting method for potential skin tissue regeneration. We found that the glacial acetic acid was an appropriate solvent used to prepare hydrophobic PCL solution with low molecular weight (16 kDa) for PCL-PVA blend, with mass ratio 1:1, without using any surfactant. The solvent was also used for the preparation of PCL scaffold with high molecular weight (80 kDa). The fabricated polymer scaffolds were then evaluated using FTIR-ATR, contact angle measurement, and tensile strength analysis. FESEM images of the PVA-PCL hybridized scaffold showed that the PCL was well dispersed in the PVA scaffold. FTIR-ATR spectra showed that the hybridized scaffold exhibited the crucial functional group of PVA and PCL at 3310.97, 1720.10, 1557.80, 1241.69, 1172.90, 1044.95, and 719.44 cm-1. The contact angle of the PVA, PCL, and PVA-PCL hybridized scaffold were 61.3o, 82.7o, and 75.9o, respectively, with tensile strength 16.5747, 2.4038, and 7.417 MPa, respectively.

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Amjad, Zahid. "Effect of Polymer Architecture on Calcium Oxalate Inhibition." Materials Performance 59, no. 2 (2020): 26–29. https://doi.org/10.5006/mp2020_59_2-26.

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In this study, the effect of polymer architecture (i.e., composition, functional group, monomer type, etc.) on calcium oxalate (CaOx) precipitation in aqueous solution was investigated using the spontaneous precipitation method. The polymers tested include natural, bio-, and synthetic homo-and copolymers. The experimental results show that performance of polymers as CaOx inhibitors strongly depends on polymer architecture. In general, polymers containing the carboxyl group perform better than co-and terpolymers containing hydrophobic and bulky comonomers. Results on CaOx crystals characterization indicate that polymers favor the formation of the calcium oxalate dihydrate phase.

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ten Wolde, P. R., and D. Chandler. "Drying-induced hydrophobic polymer collapse." Proceedings of the National Academy of Sciences 99, no. 10 (2002): 6539–43. http://dx.doi.org/10.1073/pnas.052153299.

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Liu, Chuntian, Xiaolin Wu, Xing Li, Xiaodan Yu, and Xin Zhao. "A New Hydrophobic Associating Polymer." Polymers and Polymer Composites 20, no. 1-2 (2012): 95–98. http://dx.doi.org/10.1177/0967391112020001-218.

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Zou, Wenjie, Zichuan Fang, Zhijun Zhang, and Zhenzhen Lu. "Interaction and Adsorption of Hydrophobically Modified Polyacrylamide on Silica and Asphaltene Surfaces." Advances in Polymer Technology 2019 (November 24, 2019): 1–8. http://dx.doi.org/10.1155/2019/5423178.

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The adsorption of polymers affects the cost and oil recovery in oil reservoir exploitation and the flocculation effect in the treatment of oil sand tailings. The adhesion and adsorption of a hydrophobically modified polyacrylamide (HMPAM), i.e., P(AM-NaAA-C16DMAAC), on silica and asphaltene were investigated using surface force measurements, thermodynamic analysis and quartz crystal microbalance with dissipation (QCM-D) measurement. Our study indicates that HMPAM polymer has strong interaction with both silica and asphaltene. The adhesion force of HMPAM on silica was stronger than that on asphaltene surface. Consistently, the adsorption of HMPAM was also greater on silica surface, with a more rigid layer formed on the surface. For HMPAM/silica system, the attractive interaction and the strong adhesion are mainly driven by the hydrogen bonding and electrostatic interaction. For HMPAM/asphaltene system, it is mainly due to hydrophobic interaction between the long hydrocarbon chains of HMPAM and asphaltene. Furthermore, continuous adsorption of HMPAM was detected and multiple layers formed on both silica and asphaltene surfaces, which can be attributed to the hydrophobic chains of HMPAM polymers. This work has illustrated the interaction mechanism of HMPAM polymer on hydrophilic silica and hydrophobic asphaltene surfaces, which provide insight into the industrial applications of hydrophobically modified polymer.

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Ashaduzzaman, Md, Shu Hei Kai, and Masashi Kunitake. "Investigation of Click Reaction at an Oil-Water Interface Using Hydrophobic and Hydrophilic Polymers." International Letters of Chemistry, Physics and Astronomy 11 (September 2013): 31–39. http://dx.doi.org/10.18052/www.scipress.com/ilcpa.11.31.

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Cu(I)-catalyzed Huisgen click reactions between lipophilic polymer (tri-arm azidofunctionalized polystyrene) and hydrophilic polymer (copolymer of styrene sulfonate sodium and propargyl methacrylate) were investigated and hollow capsules, consisting of composite polymer nanofilms were obtained in chloroform-water biphasic solution. Since the lipophilic polymer, or hydrophilic polymer and copper catalyst were present in the oil or aqueous phase, respectively, the cross-linking reaction proceeded only at the phase interface. The combination of lipophilic and hydrophilic polymers produced hollow capsules consisting of nanofilms with lipophilic core and hydrophilic shell.

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Ashaduzzaman, Md, Shu Hei Kai, and Masashi Kunitake. "Investigation of Click Reaction at an Oil-Water Interface Using Hydrophobic and Hydrophilic Polymers." International Letters of Chemistry, Physics and Astronomy 11 (April 2, 2013): 31–39. http://dx.doi.org/10.56431/p-96v5at.

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Sakuma, Tatsuya, Kimiko Makino, Hiroshi Terada, Issei Takeuchi, Violeta Mitova, and Kolio Troev. "Synthesis and Characterization of Amphiphilic Diblock Polyphosphoesters Containing Lactic Acid Units for Potential Drug Delivery Applications." Molecules 28, no. 13 (2023): 5243. http://dx.doi.org/10.3390/molecules28135243.

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Multistep one-pot polycondensation reactions synthesized amphiphilic diblock polyphosphoesters containing lactic acid units in the polymer backbone. At the first step was synthesized poly[poly(ethylene glycol) H-phosphonate–b-poly(ethylene glycol)lactate H-phosphonate] was converted through one pot oxidation into poly[alkylpoly(ethylene glycol) phosphate-b-alkylpoly(ethylene glycol)lactate phosphate]s. They were characterized by 1H, 13C {H},31P NMR, and size exclusion chromatography (SEC). The effects of the polymer composition on micelle formation and stability, and micelle size were studied via dynamic light scattering (DLS). The hydrophilic/hydrophobic balance of these polymers can be controlled by changing the chain lengths of hydrophobic alcohols. Drug loading and encapsulation efficiency tests using Sudan III and doxorubicin revealed that hydrophobic substances can be incorporated inside the hydrophobic core of polymer micelles. The micelle size was 72–108 nm when encapsulating Sudan III and 89–116 nm when encapsulating doxorubicin. Loading capacity and encapsulation efficiency depend on the length of alkyl side chains. Changing the alkyl side chain from 8 to 16 carbon atoms increased micelle-encapsulated Sudan III and doxorubicin by 1.6- and 1.1-fold, respectively. The results obtained indicate that these diblock copolymers have the potential as drug carriers.

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Uznanski, P., J. Pecherz, and M. Kryszewski. "Photophysical studies of hydrophobically functionalized polyionene systems in aqueous solutions." Canadian Journal of Chemistry 73, no. 11 (1995): 2041–46. http://dx.doi.org/10.1139/v95-252.

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Complexes of polyionene and anionic dyes and surfactant were prepared by exchange reaction of counterions in the parent polymer. Fluorescence studies were conducted to observe some characteristic behaviour of these complexes in water Polyionenes with aromatic hydrocarbons adopt an open conformation and there is no evidence for interpolymer interactions. On the contrary, polyionenes with long aliphatic counterions easily form microdomains in aqueous solution due to hydrophobic interaction as evidenced by an increase in excimer emission. Microdomains have an interpolymer nature, as confirmed by measurements of energy transfer from naphthalene to pyrene moieties. Polyionenes with SDS counterions interact with external surfactant molecules and form polymer–surfactant aggregates. Electrostatic repulsions between aggregates dominate on hydrophobic interaction between polymer chains and are responsible for conformational changes. Keywords: hydrophobically modified polymers, surfactants, complexation, fluorescence, nonradiative energy transfer

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Tirelli, Nicola, Angelina Altomare, Roberto Solaro, and Francesco Ciardelli. "Photomodulation of the hydrophilic properties of acrylic polymers containing side-chain azobenzene chromophores." Canadian Journal of Chemistry 73, no. 11 (1995): 1849–54. http://dx.doi.org/10.1139/v95-228.

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Partially hydrophilic polymers have been prepared by free-radical copolymerization of trans-4-acryloyloxyazobenzene with N-tert-butylacrylamide and N-isopropylacrylamide. A turbidimetric method has been adapted to investigate the dependence of the polymer hydrophilic–hydrophobic balance on chemical composition and extent of photoisomerization of side-chain azobenzene chromophores. Irradiation at 366 nm of polymer suspension in THF–water induces the isomerization of azobenzene groups from the planar apolar trans form to the nonplanar polar cis form. Correspondingly, the solution turbidity is appreciably modified. Experimental results are discussed in terms of polymer structural parameters. Suspension stability and the possibility of carrying out photochemical cycles have been also investigated. Keywords: photochromic polymers, photoresponsive polymer, photomodulation of polymer properties, azobenzene-containing polymers, acryloyloxyazobenzene, N-tert-butylacrylamide.

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Akiba, Isamu, Ryosuke Nakanishi, Masaki Kugimoto, Daisuke Kugimoto, Yusuke Sanada, and Kazuo Sakurai. "ASAXS Study on Spatial Distribution of Hydrophobic Compounds in Polymer Micelles." Acta Crystallographica Section A Foundations and Advances 70, a1 (2014): C1580. http://dx.doi.org/10.1107/s2053273314084198.

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In drug delivery system (DDS) using polymer micelles as drug carrier, DDS properties are related to spatial distribution of drug compounds in the micelles [1]. Because the spatial distribution of drug compounds should strongly depend on interactions and solubility of drug compounds in the micelles, elucidation of the relation between chemical structures of drug compounds and their spatial distribution in the micelle is much important. Thus, in this study, we examine to elucidate the relation between chemical features and spatial distribution of drug compounds in polymer micelles by using anomalous small-angle X-ray scattering (ASAXS). To apply the ASAXS near bromine K-edge for analysis [2] of spatial distribution of drug compounds in polymer micelles, we employ 4 different bromine-labeled hydrophobic compounds as model drug compounds and polymer micelles composed of poly(dimethylaminoethyl methacrylate)-block-poly(methyl methacrylate) (PDMAEMA-b-PMMA). Figure shows SAXS and resonant term obtained from ASAXS near bromine K-edge for the polymer micelles containing 9-bromofluorene (BrF). The domain size estimated from the resonant term is much smaller than that of hydrophobic PMMA core of the micelle. Therefore, When BrF, which is highly hydrophobic and scarcely dissolved in hydrophobic PMMA, is incorporated in the polymer micelle, BrF forms small droplet in the hydrophobic core composed of PMMA. For the micelles incorporating bromobenzene, which as similar properties of BrF, similar result is obtained. On the other hand, 4-bromobenzyl alcohol and ethyl 2-bromoethyl propionate, which are miscible with PMMA, are homogeneously dispersed in the PMMA core of the micelles. These results indicate that highly hydrophobic compounds forms small droplet in hydrophobic core, and introduction of polarity to the compounds causes expansion of the area existing the hydrophobic compounds in polymer micelle.

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Nagre, Robert Dery, Prince Appiah Owusu, Sampson Kofi Kyei, Johannes Ami, and Isaac Kwasi Frimpong. "Efficacy of Synthetic Hydrophobic Associative Tetrapolymers for Improved Recovery of Viscous Oil in Sandpack Model." Chemistry & Chemical Technology 18, no. 4 (2024): 630–41. https://doi.org/10.23939/chcht18.04.630.

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This study examined the suitability of hydrophobic associative tetrapolymers (HATs) for enhanced oil recovery through sandpack flooding. Two novel hydrophobic associative tetrapolymers, herein designated as HAT-1 and HAT-2 were synthesised via free radical polymerisation and the structures were confirmed by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance (1H NMR). HAT-1 composed of acrylamide - hydroxyethyl methacrylate - N- vinyl pyrrolidone - N,N-dimethyl acrylamide and HAT-2 consisted of acrylamide - sodium 2-acrylamido-2-methyl propane sulphonate - diallyldimethylammonium chloride - lauryl methacrylate. Comparative tests were carried out under laboratory conditions on the oil displacement efficiencies of the two HAT polymers. The incremental oil recovered using polymer HAT-1 and HAT-2 injection after water flooding were 33.7% and 36.2%, respectively. Combining the oil recovered from water flooding followed by polymer flooding both scenarios, the cumulative recovered using HAT-2, 83.3 % was relatively higher than that of HAT-1, 74.4%. These values are relatively high from the economic perspective. Based on brine viscosity enhancement, mobility ratio reduction and additional oil recovery, HAT-2 polymer exhibited a relatively higher potential to improve oil recovery for reservoirs with characteristics similar to the experimental conditions for this work.

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Perron, Gérald, Josée Francoeur, Jacques E. Desnoyers, and Jan C. T. Kwak. "Heat capacities and volumes in aqueous polymer and polymer–surfactant solutions." Canadian Journal of Chemistry 65, no. 5 (1987): 990–95. http://dx.doi.org/10.1139/v87-169.

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The apparent molar volumes and heat capacities of aqueous mixtures of neutral polymers and ionic surfactants were measured at 25 °C. The polymers chosen were poly(vinylpyrrolidone) (PVP) and poly(ethyleneoxide) (PEO) and the surfactants were the C8, C10, and C12 homologs of sodium alkylsulfates and the C10, C12, and C16 homologs of alkyltrimethylammonium bromides. The polymer–surfactant interactions depend on the nature of both components and on the chain length of the surfactant. The thermodynamic properties of the cationic surfactants are essentially the same in the absence and presence of polymer indicating little surfactant–polymer interaction. On the other hand, the thermodynamic properties of anionic surfactants are shifted, upon the addition of polymers, in the direction of enhanced hydrophobic association. The effect increases with the surfactant chain length and with the polymer concentration. The effect is larger with PVP than with PEO.

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Biswas, Atanu, H. N. Cheng, Sanghoon Kim, Carlucio R. Alves, and Roselayne F. Furtado. "Hydrophobic Modification of Cashew Gum with Alkenyl Succinic Anhydride." Polymers 12, no. 3 (2020): 514. http://dx.doi.org/10.3390/polym12030514.

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Cashew gum (CG) shows promise of being useful as an agro-based raw material for the production of eco-friendly and biodegradable polymers. In this work, we modified this water-soluble polymer with alkenyl succinic anhydride in order to attach a hydrophobic group to it. The modification used two reagents: octenyl succinic anhydride and tetrapropenyl succinic anhydride. Reactions were conducted at 120 °C using dimethyl sulfoxide as a solvent, with conversions better than 88%. Samples with degrees of substitution (DS) between 0.02 and 0.20 were made. The resulting polymers were characterized using 1H NMR, 13C NMR, FTIR, TGA, and GPC. The addition of the hydrophobe decreased the affinity of cashew gum for water absorption. Hydrophobically modified polysaccharides are often used as polymeric emulsifiers, thickeners, and compatibilizers; we anticipate that these new hydrophobically modified CGs may be used for the same applications.

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Dautriat, Margaux, Pierre Montméat, and Frank Fournel. "(First Best Student Paper Award) Polymer to Silicon Direct Bonding for Microelectronics." ECS Meeting Abstracts MA2023-02, no. 33 (2023): 1591. http://dx.doi.org/10.1149/ma2023-02331591mtgabs.

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Direct bonding consists in spontaneously bringing into contact two solid surfaces without any intermediate liquid. A liquid is defined here as a being thick enough to have fluid characteristics. Silicon direct bonding is widely used in microelectronics, for instance for the production of silicon-on-insulator substrates (for transistor manufacturing). Direct bonding can be performed between identical surfaces, for example, two silicon substrates. However, direct bonding is also feasible with two different surfaces such as silicon and metal. Direct bonding of two solid materials requires very strict surface conditions such as planarity, particle cleanliness and low surface roughness. The surface Root Mean Square (RMS) roughness should be lower than 0.5 nm for hydrophilic silicon bonding and 0.3 nm for hydrophobic silicon bonding [1]. We will focus here on direct bonding with polymer films. It is a quite innovative bonding as polymers are materials with very different properties compared to silicon. They are indeed not crystalline, much less rigid and most of the time hydrophobic. Five different polymers thin films are used to evaluate direct bonding with polymers: LOR2A, BARC AR26N, SOC HM8102, TOK TDMR and LTC9310. Thicknesses are between 32 nm and 6 µm. Those polymers are deposited on 200 or 300 mm diameter Si substrates. First of all, polymers are characterized by Fourier-Transform Infrared Spectroscopy (FTIR), spectroscopic ellipsometry and Thermogravimetric Analysis (TGA). Contact angles of the different polymers are in the 58° to 77° range, a feature which is a characteristic of hydrophobic surfaces. For comparison, the contact angle is lower than 5° for hydrophilic silicon (SiO2) and 78° for hydrophobic H-passivated silicon (Si). The surface roughness of the five different polymers is evaluated by Atomic Force Microscopy (AFM), with RMS roughness ranging from 0.29 to 0.40 nm found. Such values are in-between the 0.3 nm and 0.5 nm thresholds for hydrophobic and hydrophilic surface bonding, respectively. However, direct bonding is feasible between polymers and hydrophilic or hydrophobic silicon surfaces in all cases. Bonding waves are observed and characterized by infrared imaging. Adhesion energies for bonding with the five different polymers are between 40 and 70 mJ/m². Meanwhile, the bonding wave velocity is in the 10-19 mm/s range. Data for polymer to hydrophilic silicon bonding are provided in Table 1. They can be compared to Table 2 data for hydrophilic and hydrophobic silicon bonding (i.e. ceramic bonding) as they have equivalent water contact angles. Polymer to Si direct bonding has higher adhesion energy and bonding wave velocity than SiO2 to Si ceramic direct bonding. The bonding interface, characterized by Scanning Acoustic Microscopy (SAM), does not reveal any bonding defects. Bonded stacks can be annealed at different temperatures. Acoustic images of bonding with BARC are shown in Figure 1 for different annealing temperatures. It is possible to measure their adherence energy after annealing using the DCB (Double Cantilever Beam) technique [2]. BARC adherence energies are given in Figure 2. As with ceramic bonding, bonding strengthens as the temperature increases. The covalent bonds density should increase during the annealing. The bonding degradation at 250°C and especially 300°C evidenced by Scanning Acoustic Microscopy (SAM) is in line with TGA findings on polymer degradation, with a threshold at 280°C. X-ray Photoelectron Spectroscopy is being used to identify interactions between the silicon surface and the polymer. A mechanism will be proposed for these innovative bondings. [1] H. Moriceau et al., « Overview of recent direct wafer bonding advances and applications », Adv. Nat. Sci. Nanosci. Nanotechnol., vol. 1, no 4, p. 043004, févr. 2011, doi: 10.1088/2043-6262/1/4/043004. [2] W. P. Maszara, G. Goetz, A. Caviglia, et J. B. McKitterick, « Bonding of silicon wafers for silicon‐on‐insulator », J. Appl. Phys., vol. 64, no 10, p. 4943-4950, nov. 1988, doi: 10.1063/1.342443. Figure 1

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Yadav, Deepak, Suruchi Suri, Anis Chaudhary, et al. "Stimuli responsive polymeric nanoparticles in regulated drug delivery for cancer." Polish Journal of Chemical Technology 14, no. 1 (2012): 57–64. http://dx.doi.org/10.2478/v10026-012-0060-y.

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Stimuli responsive polymeric nanoparticles in regulated drug delivery for cancer Stimuli-responsive drug delivery system is a concept in which a drug is delivered at a suitable rate in response to stimuli. States of diseases may cause an alteration in some parameters of the body (e.g. in tumors) and the onset and offset of the drug delivery can be done by using this as a stimuli or a "trigger". Stimuli-responsive ("intellectual" or "sharp") resources and molecules show abrupt property changes in response to miniature changes in external stimuli such as pH, temperature etc. For regulated drug delivery, environmental stimuli such as pH and temperature, which undertake phase transition in polymer system, have been investigated. Thermally-responsive polymers can be tuned to a preferred temperature variety by copolymerization with a hydrophilic co-monomer or a hydrophobic co-monomer. Hydrophilic co-monomers increase the LCST while hydrophobic co-monomers decrease the LCST. The stimuli responsive polymer for regulated drug delivery can contain a polymer and copolymers having equilibrium of hydrophilic and hydrophobic groups. A number of these polymers have been investigated extensively and some success in drug delivery with them has been achieved, such as polymers and copolymers of N-isopropylacrylamide, PLGA, and PLA, HEMA etc. Thus this review is designed for stimuli pH and temperature responsive polymeric nanoparticles, which would be helpful to treat various cronic diseases such as cancer and others, for scientists in the field of the regulated drug delivery system.

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Wobser, Victoria, Kejia Yang, Romil Modi, Wyatt Archer, Yogi Patel, and Walter Voit. "Light-Activated Hydrophobic Adhesive for Shape-Memory Polymer Nerve Cuffs." MRS Advances 1, no. 1 (2015): 1–7. http://dx.doi.org/10.1557/adv.2015.42.

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ABSTRACTIn this study, three hydrophobic polymers are investigated as potential adhesives for a shape memory polymer nerve cuff. At room temperature, the adhesive candidate exhibited a maximum lap shear stress of 1.7251 MPa, compared to 0.87641 MPa and 2.1815 MPa for two commercially available biocompatible adhesives.

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Rowe, Molly, Guo Hui Teo, James Horne, Omar Al-Khayat, Chiara Neto, and Stuart C. Thickett. "High Glass Transition Temperature Fluoropolymers for Hydrophobic Surface Coatings via RAFT Copolymerization." Australian Journal of Chemistry 69, no. 7 (2016): 725. http://dx.doi.org/10.1071/ch15787.

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The preparation of polymer thin films or surface coatings that display a static water contact angle >95° often requires hierarchical roughness features or surface functionalization steps. In addition, inherently hydrophobic polymers such as fluoropolymers often possess low glass transition temperatures, reducing their application where thermal stability is required. Herein, the first reported synthesis of 2,3,4,5,6-pentafluorostyrene (PFS) and N-phenylmaleimide (NMI) via reversible addition–fragmentation chain-transfer (RAFT)-mediated free radical polymerization is presented, with a view towards the preparation of inherently hydrophobic polymers with a high glass transition temperature. A suite of copolymers were prepared and characterized, and owing to the inherent rigidity of the maleimide group in the polymer backbone and π–π interactions between adjacent PFS and NMI groups, very high glass transition temperatures were achieved (up to 180°C). The copolymerization of N-pentafluorophenylmaleimide was also performed, also resulting in extremely high glass transition temperature copolymers; however, these polymers did not exhibit characteristics of being under RAFT control. Thin films of PFS-NMI copolymers exhibited a static contact angle ~100°, essentially independent of the amount of NMI incorporated into the polymer.

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Igawa, Manabu, Hironobu Okuma, and Kiyoshi Matsumoto. "Specific Permeation of Hydrophobic Solutes across a Hydrophobic Polymer Membrane." Bulletin of the Chemical Society of Japan 78, no. 9 (2005): 1702–3. http://dx.doi.org/10.1246/bcsj.78.1702.

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Qin, Chuan, Guang Hua Wen, Lang Zhou, Jian Bo Jin, and Xin Shi. "The Development and Performance Evaluation of Hydrophobic Association Polymer Pre-Cross Linked Particulate." Advanced Materials Research 418-420 (December 2011): 571–76. http://dx.doi.org/10.4028/www.scientific.net/amr.418-420.571.

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Due to the shortage of traditional pre-cross linked particulate, such as suspension property, temperature and salt tolerance, and injectivity, this paper developed hydrophobic association polymer pre-cross linked particulate based on hydrophobic association polymer. The performance evaluation of rheological behavior, microstructure and mobility control ability demonstrate that hydrophobic association polymer pre-cross linked particulate can partly dissolved in water, and has certain viscosity thickening and suspension property; it partly cross linking forming mesh structure, and has strong resilience; it can deform through the porous media after swelling, and has good mobility control ability.

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Alalwiat, Ahlam, Sarah E. Grieshaber, Bradford A. Paik, Kristi L. Kiick, Xinqiao Jia, and Chrys Wesdemiotis. "Top-down mass spectrometry of hybrid materials with hydrophobic peptide and hydrophilic or hydrophobic polymer blocks." Analyst 140, no. 22 (2015): 7550–64. http://dx.doi.org/10.1039/c5an01600b.

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Tan, Hongzhong, Jincheng Mao, Wenlong Zhang, et al. "Drag Reduction Performance and Mechanism of Hydrophobic Polymers in Fresh Water and Brine." Polymers 12, no. 4 (2020): 955. http://dx.doi.org/10.3390/polym12040955.

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Three kinds of drag reducer were synthesized by inverse emulsion polymerization and named PHWAM-1, PHWAM-2, and PHWAM-3. Drag reduction (DR) tests showed that the three drag reducers have different DR characteristics in fresh water and various saline waters because of their different types of hydrophobic monomers. PHWAM-1, without hydrophobic monomers, performs better in fresh water, while PHWAM-2 and PHWAM-3, with hydrophobic monomers, perform better in brine. In addition, PHWAM-3, which has twin-tailed hydrophobic monomers, performs best in high-concentration brine. Measurements of micro-particle size and observations of spatial structure suggest that although the stronger hydrophobic polymer has no DR advantage over a linear polymer in fresh water, the molecular chains form a mutually associative supporting structure that improves the DR performance over that of a linear polymer in high-concentration brine.

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Zhang, Yi, Qing Jiang, Xinyi Liu, et al. "A Study of Hydrophobically Modified Pullulan Nanoparticles with Different Hydrophobic Densities on the Effect of Anti-Colon Cancer Cell Efficiency." Journal of Biomedical Nanotechnology 17, no. 10 (2021): 1972–83. http://dx.doi.org/10.1166/jbn.2021.3173.

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To discuss the effect of hydrophobic groups of a polymer on the structural properties and function of polymer nanoparticles (NPs), we grafted chenodeoxycholic acid (CDCA) with pullulan (PU) to form hydrophobically modified PU (PUC). Three PUC polymers, namely, PUC-1, PUC-2, and PUC-3, with different degrees of substitution were designed by changing the feed ratio of CDCA and PU. 1H-NMR spectra showed that the PUC polymer was successfully synthesized, and the degrees of hydrophobic substitution for PUC-1, PUC-2, and PUC-3 were calculated to be 10.66%, 13.92%, and 16.94%, respectively. The PUC NPs were prepared by the dialysis method and were shown to be uniformly spherical by transmission electron microscopy (TEM). The average sizes were about (220±10) nm, (203±7) nm, and (163±6) nm under dynamic light scattering (DLS) for PUC-1 NPs, PUC-2 NPs, and PUC-3 NPs, respectively. Drug release experiments showed that the three PUC/DOX NPs exhibited good sustained release. At 48 h, the IC50 of doxorubicin in inhibiting colon cancer HCT116 cells was 0.0904 μg/mL. A cell study showed that PUC-3/DOX NPs had the highest uptake efficiency by HCT116 cells with the most cytotoxicity and inhibited the migration of HCT116 cells with the highest efficiency. The structural properties and function of polymer NPs were closely related to the hydrophobic groups in the polymer, and NPs with higher hydrophobicity showed a smaller size, higher drug capacity, and greater cell efficiency.

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Khutoryanskiy, Vitaliy V. "Synthesis and Solution Properties of Hydrophobically Modified Polysaccharides." Eurasian Chemico-Technological Journal 7, no. 2 (2017): 99. http://dx.doi.org/10.18321/ectj621.

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Hydrophobically modified polymers are amphiphilic macromolecules mainly constituted of a hydrophilic backbone and hydrophobic side groups. In aqueous solutions these polymers undergo inter- or intra-molecular hydrophobic association, which results in unusual properties useful for a number of practical applications. The areas of application of these polymers include associative thickeners for enhanced oil recovery, pharmaceuticals, personal care formulations, coatings, adhesives, surfactants, emulsifiers, etc. This review presents the analysis of a literature data on preparation of hydrophobically modified polysaccharides (HMP) and their properties in aqueous solutions. Some of the synthetic methods used for hydrophobic modification of non-ionic (cellulose ethers, starch, dextran, pullulan, etc.), anionic (carboxymethylcellulose, hyaluronic acid, pectic acid, alginic acid, heparin) and cationic olysaccharides (chitosan) are presented. The methodology used for the investigation of solution properties of hydrophobically modified polysaccharides is discussed. Special attention is paid to aggregate and micelle formation in solutions of hydrophobically modified polysaccharides, solubilization of hydrophobic compounds, their rheological properties and surface activity. The effects of polymer architecture (level of hydrophobic substitution, nature of hydrophobic groups, molecular weight of a hydrophilic backbone, etc.), concentration, temperature, presence of inorganic salts and organic solvents on solution properties of hydrophobically modified polysaccharides are discussed. Some applications of hydrophobically modified polysaccharides are briefly highlighted.

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Chu, Donghui, Akihiro Nemoto, and Hiroshi Ito. "Hydrophobic property of hierarchical polymer surfaces fabricated by precision tooling machine." Journal of Polymer Engineering 34, no. 5 (2014): 477–82. http://dx.doi.org/10.1515/polyeng-2013-0327.

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Abstract Poly(methylmethacrylate) surfaces were patterned with micropillars and micro-micro hierarchical structures. Patterning was achieved by applying direct fabrication on polymer surfaces. The micro-manufacturing method has many advantages of precise control of dimensions, low cost, and short process time compared to other micro-manufacturing techniques of polymers. Fabricated structures were controlled accurately to <10% of the error range. Patterned micro-micro hierarchical polymer structures indicated a contact angle >130° without additional coatings. Furthermore, fabricated structures show good durability in terms of contamination and mechanical robustness for 2 months.

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