Academic literature on the topic 'Formaldehyde solution'

A series of hydrophobic ionic liquids (ILs) have been employed to extract acetic acid (AcOH) or formaldehyde (HCHO) from aqueous solutions at atmosphere pressure. The ILs, mainly trihexyl(tetradecyl)phosphonium ([P6,6,6,14]+) carboxylate based ILs, were tested as a function of the anion chain length, which ranges from isobutyrate ([IB]-) to dodecanoate ([D]-). Most of these ILs show a large two-phase region and high extraction efficiency. Furthermore, tetraoctylphosphonium ([P8,8,8,8]+) and trihexyl(tetradecyl)ammonium ([N6,6,6,14]+) based ILs were also investigated to study the effect of the cation on extraction performance. Besides pure IL extraction, the mixture of IL and other chemicals, such as matched carboxylic acid, alkane and ester, were also investigated on extraction. The matched carboxylic acid could enhance the extraction performance and thus could be called ‘enhancer’. A balance point could be found for the ratio IL/enhancer to obtain a better extraction in each {H2O + AcOH + IL/enhancer} system, compared with the corresponding pure IL liquid-liquid equilibrium (LLE). Several ILs, including [P6,6,6,14]+ based ILs and imidazolium based ILs, were investigated on extraction of HCHO. Among these ILs, the imidazolium based ILs performed better than the [P6,6,6,14]+ based ILs in terms of two-phase region, hydrophobicity of IL-rich phase and partition coefficient/relative selectivity. The UNIQUAC method was employed to correlate the LLE data for pure IL systems. Some physical property data, such as density and viscosity, of ILs were correlated. The Joback group contribution method was used to predict the heat capacities of some ILs in this work. These correlations with low deviations made it possible for ILs to be further studied in Aspen process modelling.

The contamination of water recourses by heavy metals is a serious worldwide environmental problem. Industrial activities, mining and coal combustion are typical contamination sources. Removal of these metals from wastewater effluents is crucial as this contamination is non-biodegradable and highly toxic. Extensive research has been carried out to introduce new materials which alleviate these metals from wastewater effluents before their discharge into water bodies such as rivers and lakes. Conventional methods to remove heavy metals from wastewater include chemical precipitation, ion-exchange and chelation-adsorption. Adsorption is an important and developing research area because of the new material types available according to the application. Furthermore, it is standard process to place the adsorbent in a column and pump the wastewater through in a continuous system. It is also a cost-effective process. Chelating adsorbents are typically characterised by functional groups containing 0, N, S, and P donor atoms which coordinate to different heavy metal ions. It is necessary that the adsorbent has a high capacity and that the kinetics of adsorption is sufficiently fast. Polyaminepolycarboxylic (PAPC) acids are strong chelating agents and form stable chelates with different types of metals: transition, lanthanides and actinides. In spite of its exceptional chelating power, many of the PAPC compounds - such as DTPA (8-coordinations), CDTA (6-coordinations) and NTA (4-coordinations) - have not been thoroughly studied for use as active sites in adsorbent materials for heavy metal remediation from contaminated water effluents. Furthermore, the effect of the number of coordination groups on the adsorption behaviour has not been investigated. Use of these strong chelating agents (PAPC) for heavy metal removal by a polymeric adsorbent is presented in this study, with discussion of the chelation mechanism and affinity. The PAPC chelating agents were anchored on melamineformaldehyde (MF) gel. Although MF gel has suitable chemical and physical properties allowing the production of an adsorbent for heavy metal removal, it has not been studied. MF gel is porous and its matrix has a suitable platform to functionalize with some chelating compounds. PAPC-modified melamine-formaldehyde matrix is easy to produce compared to conventional chelating resins based on styrene/divinylbenzene. In this work, melamine-formaldehyde-polyaminepolycarboxylic acid (MF-PAPC) chelating adsorbents were synthesised by anchoring polyaminepolycarboxylic acids (PAPC) to melamine by the reaction of the carboxylic group of PAPC with a primary amine group of melamine forming a covalent amide bond during MF matrix formation. A series of samples of these adsorbents were prepared by varying water content, acidity of water and temperature as parameters to control the properties of the product. Samples of MF-DTPA, MF-NTA and MF-CDTA were chemically characterized using IR, elemental analysis, TPD-MS, 13C-NMR and 15N-NMR. Physical characterisation was carried out using BET, FE-SEM, and XRD techniques. Elemental analysis and BET results were used to select optimum samples for adsorption experiments. Selected MF-PAPC adsorbent samples are hydrophilic, amorphous and rigid. The content of PAPC in the dry adsorbent samples ranges from 1.08 to 2.28 mmole g⁻¹. The MF-PAPC adsorbents have reasonable surface areas (ranges from 159 to 179 m² g⁻¹) and a mesoporous structure (average pore diameter: 19 - 130 Å). The adsorption performance of MF-PAPC adsorbents was investigated against environmentally problematic divalent metal ions, namely, Cu(II), Co(II), Cd(II) and Zn(II). The adsorption behaviour of these adsorbents was characterised using mixture solutions of these four ions. The effects of different controlling parameters (solution initial pH, temperature, metal ions initial concentration and contact time) on adsorption were considered. Experimental data was fitted to the selected kinetic and isotherm models to suggest the best models to represent the adsorption process on MF-PAPC adsorbents. The thermodynamic parameters (adsorption free energy, enthalpy and entropy) were also calculated and a mechanism of adsorption is suggested according to the evaluation of the results. It was found that MF-PAPC adsorbents follow reversible first order and pseudo second order models to represent the adsorption kinetics. The Langmuir isotherm model gives the best representation of the adsorption processes. These findings indicate the chemical and reversible nature of the adsorption process. Thermodynamically, the adsorption was found to be spontaneous and exothermic. The entropy change shows that adsorption is not favourable. The results indicate that chelation and ion exchange are the mechanisms of adsorption with chelation the dominant type especially at lower temperatures and higher initial pH values. The PAPC type controls the affinity order of the four heavy metals. MF-PAPC adsorbents are distinguished by chelation-adsorption. The adsorption can be universal, or selective according to the PAPC type. Moreover, the selectivity order is different and depends on the PAPC type. MF-PAPC adsorbents can be used for metal-separation applications due to the higher affinity towards transition elements, lanthanides and actinides with respect to alkali and alkaline earth metals. The elution of the adsorbed metal ions was successfully accomplished using a solution of EDTA due to its high chelation power. The MF-DTPA adsorbent was used in a packed column for removal of the Cu(II) ion in a continuous up-flow system. The parameters of the study were: Bed height, flow rate and initial concentration. The Thomas model was used to fit the kinetic data. The BDST model was used to examine the possibility of scaling-up the laboratory set-up to industrial scale. The capacity of dsorption was found to be sensitive to bed height (positive: due to mass transfer), initial concentration (positive: due to concentration driving force) and flow rate (negative: due to contact time). It was found that the adsorption zone moves up the column at a constant speed for different bed heights. Hence, the process can be scaled-up for practical use using a BDST model.

L'objet de cette thèse est l'étude des interactions du formaldéhyde avec l'eau, système qui possède à la fois un intérêt fondamental et des applications dans les domaines de la chimie atmosphérique et de l'astrochimie. Nous avons déterminé par spectroscopie d'absorption infrarouge la constante de Henry du formaldéhyde, qualifiant sa solubilité dans l'eau ou la glace, pour des solutions aqueuses de fraction molaire inférieure à 1%, et des températures entre 270 et 295 K, représentantes des conditions atmosphériques.La composition de ces solutions a été étudiée par calorimétrie différentielle à balayage, diffraction des rayons X et spectroscopie Raman pour différentes concentrations (1-30 % en mol. frac.) et températures (183-453 K). L'analyse des solutions gelées a montré différentes phases cristallines selon les conditions expérimentales. Nous avons fait la première observation, par spectroscopie Raman, du formaldéhyde en phase liquide sous sa forme H2CO, pour des températures supérieures à 363 K.Le mécanisme d'hydratation de formaldéhyde en méthylène glycol CH2(OH)2 a été étudié par calculs ab initio dans les phases gazeuse et liquide. Un mécanisme coopératif a été mis en évidence et les effets de l'ajout de molécules d'eau autour du soluté sur les géométries et les énergies ont été analysés. Des simulations de dynamique moléculaire ab initio ont été réalisées pour étudier les systèmes comprenant des molécules d'eau et de méthylène glycol ou de H(CH2O)2OH, à 300 K. Les structures préférentielles des solutés et les effets de polarisation dus à l'interaction du soluté avec le solvant ont été déterminés. Les spectres Raman calculés ont été comparés aux expérimentaux<br>The subject of this work is the study of the interactions of formaldehyde with water, which has both a fundamental interest and applications in the fields of atmospheric chemistry and astrochemistry. We focused first on the determination, by infrared absorption spectroscopy, of Henry's law constant for formaldehyde, characterizing its solubility into water or ice, for aqueous solutions of molar fraction below 1%, and temperatures between 270 and 295 K, representative of the atmospheric conditions. The composition of the formaldehyde aqueous solutions has also been studied, using differential scanning calorimetry, X-ray diffraction and Raman spectroscopy, for a large range of concentrations (1-30 % mol. frac.) and temperatures (183-453 K). The analysis of the frozen solutions showed different crystallized phases depending on the experimental conditions. We made the first observations, by Raman spectroscopy, of formaldehyde in the liquid phase under its gas form, for temperatures above 363 K. The hydration mechanism of formaldehyde into methylene glycol CH2(OH)2 has been investigated by ab initio calculations in the gas and liquid phases. A cooperative mechanism has been highlighted and the effects of additional water molecules around the solute on the geometries and on the energies have been analyzed. We also used ab initio molecular dynamics to study systems comprising water molecules and methylene glycol or the next oligomer HCH2O)2OH, at 300 K. The preferred structures of the solute and the polarization effects due to the interaction of the solute with the solvent have been determined. Calculated Raman spectra were compared to the experimental ones

Sur Pt et Pt platine, la reduction de Co en milieu organique contenant de l'eau, conduit a la formation de methanol avec un rendement de 47% : co+4h**(+)+4e**(-)->ch::(3)oh. Le potentiel auquel a lieu cette reaction (-2,5 vvsag/ag**(+)10**(-2)m, est en accord aec une reduction simultanee de co et de h**(+) et une reaction entre les especes adsorbees sur l'electrode d'influence des adatomes sur les produits issus de l'oxydation du glyoxal et de l'ethylene glycol a ete etudiee en milieu hclo::(4) hclo::(4),n, h::(2)so::(4)2m et kno::(3)m de concentration de certaines especes, comme l'acide glyoxylique, varie enormement avec l'addition d'adatomes (ag, sn9 pour favoriser la formation d'acide formique par oxydation du glyoxal. L'oxydation de l'ethylene-glycol conduit esentiellement a la formation d'aldehyde ou d'acide formique sur electrode de pt

L'objet de cette thèse est l'étude des interactions du formaldéhyde avec l'eau, système qui possède à la fois un intérêt fondamental et des applications dans les domaines de la chimie atmosphérique et de l'astrochimie. Nous avons déterminé par spectroscopie d'absorption infrarouge la constante de Henry du formaldéhyde, qualifiant sa solubilité dans l'eau ou la glace, pour des solutions aqueuses de fraction molaire inférieure à 1%, et des températures entre 270 et 295 K, représentantes des conditions atmosphériques.La composition de ces solutions a été étudiée par calorimétrie différentielle à balayage, diffraction des rayons X et spectroscopie Raman pour différentes concentrations (1-30 % en mol. frac.) et températures (183-453 K). L'analyse des solutions gelées a montré différentes phases cristallines selon les conditions expérimentales. Nous avons fait la première observation, par spectroscopie Raman, du formaldéhyde en phase liquide sous sa forme H2CO, pour des températures supérieures à 363 K.Le mécanisme d'hydratation de formaldéhyde en méthylène glycol CH2(OH)2 a été étudié par calculs ab initio dans les phases gazeuse et liquide. Un mécanisme coopératif a été mis en évidence et les effets de l'ajout de molécules d'eau autour du soluté sur les géométries et les énergies ont été analysés. Des simulations de dynamique moléculaire ab initio ont été réalisées pour étudier les systèmes comprenant des molécules d'eau et de méthylène glycol ou de H(CH2O)2OH, à 300 K. Les structures préférentielles des solutés et les effets de polarisation dus à l'interaction du soluté avec le solvant ont été déterminés. Les spectres Raman calculés ont été comparés aux expérimentaux<br>The subject of this work is the study of the interactions of formaldehyde with water, which has both a fundamental interest and applications in the fields of atmospheric chemistry and astrochemistry. We focused first on the determination, by infrared absorption spectroscopy, of Henry's law constant for formaldehyde, characterizing its solubility into water or ice, for aqueous solutions of molar fraction below 1%, and temperatures between 270 and 295 K, representative of the atmospheric conditions. The composition of the formaldehyde aqueous solutions has also been studied, using differential scanning calorimetry, X-ray diffraction and Raman spectroscopy, for a large range of concentrations (1-30 % mol. frac.) and temperatures (183-453 K). The analysis of the frozen solutions showed different crystallized phases depending on the experimental conditions. We made the first observations, by Raman spectroscopy, of formaldehyde in the liquid phase under its gas form, for temperatures above 363 K. The hydration mechanism of formaldehyde into methylene glycol CH2(OH)2 has been investigated by ab initio calculations in the gas and liquid phases. A cooperative mechanism has been highlighted and the effects of additional water molecules around the solute on the geometries and on the energies have been analyzed. We also used ab initio molecular dynamics to study systems comprising water molecules and methylene glycol or the next oligomer HCH2O)2OH, at 300 K. The preferred structures of the solute and the polarization effects due to the interaction of the solute with the solvent have been determined. Calculated Raman spectra were compared to the experimental ones

Définition rigoureuse du repère d’Eckart et démonstration de l'isomorphisme des espaces internes associés aux membres d'une série isotopique : l'un d'entre eux fournit une interprétation physique des coordonnées de Wilson et permet l'affinement du champ de forces commun à une série. Obtention de forces ab initio réalistes en utilisant des facteurs d'échelle aux diverses coordonnées de symétrie locale et transférables entre groupes de même géométrie. Optimisation pour la série éthylène, butadiène, méthylène-imine, éthylidène-imine, n-méthyl-méthylène-imine n-méthyl-éthylène-imine, allylène-imine; transfert pour la construction des champs de forces des ions tétraméthyl-méthylène- et -allylène-iminium, et attribution des modes de vibrations.

碩士<br>國立臺灣大學<br>工程科學及海洋工程學研究所<br>103<br>In bottom layer of Internet of Things(M2M) , there would be a lot of sensors to detect our environment in several applications such as smart home and air monitoring . Air pollution influences human health and can cause a number of diseases.The one of major air pollutiants is volatile organic compounds (VOCs) especially in BTEX and formaldehyde can cause cancer to human beings .Therefore, developing a low cost,low power consumption and reliable gas sensor is very important for sensing technology. In this work ,we demonstrated graphene material blended with Poly(methyl methacrylate,PMMA,M=15,000) composite inks deposited between gold electrode by spin coating method .The deposited graphene composite films with different mixture concentration are sensing materials for VOCs chemiresister gas sensors in room temperature.The sensor response to several VOCs gas including methanol ,ethanol , acetone , benzene ,toluene , o-xylene, formaldehyde and water vapor are investigated. The sensors selectivity ,repeatability and stability,duration are also examined .The graphene material are prepared and selectively blended with PMMA both in dispersant Tetrahydrofuran(THF) to become conductive self-assembly composite materials . We also tested the difference of sensing VOCs characteristics between spin coated pure graphene films and graphene /PMMA composite films. The optional concentration of graphene composite spin coated films show good sensor response to formaldehyde vapor with resistance change about 0.5%~30% after exposing to each vapor concentration(about 10ppm~600ppm) in room temperature .We finally use instruments such as FTIR,SEM,XRD and Raman to analysis materials .We also infer the possible sensing mechanism between the graphene-PMMA composites and the formaldehyde.

超臨界水中的溶解和化學反應受到一系列因素的影響，如溶解能，熵以及溶液密度等，是決定化學平衡的基本熱力學量，同時這些又受到溫度和壓強的控制。爲了解釋這些因素的影響，有必要把量子化學的靜態優化與分子動力學模擬相結合和比較。通過量子化學可以得到0K下的優化結構，而分子動力學模擬可以提高實際時間的勢能面。本論文的研究，主要圍繞在氣態下甲醛分子HCHO和甲酸分子HCOOH跟不同數目水分子H2O結合的水合簇結構，以及在常溫水溶液和超臨界水溶液中，甲醛HCHO和甲酸HCOOH的溶解結構和溫度所帶來的熱效應，最後研究甲酸HCOOH在水催化下的離解反應機理。<br>使用化學計算軟件Gaussian03和密度泛函理論方法，用6-311++G(d,p)基組來計算和研究氣態下甲醛分子和甲酸分子的水簇合物。通過不同數目的水分子所得到的最穩定簇合物的結構和能量，來研究甲醛分子HCHO，甲酸根離子HCOO⁻以及甲酸分子HCOOH與水分子相互結合時的氫鍵作用力強弱和簇合物的穩定性。同時，也考慮了甲酸酸解后的水簇合物結構，通過與沒有酸解的水簇合物的比較，為進一步瞭解水溶解中甲酸的酸解離情況提供寶貴的信息。<br>使用基於贗勢和平面波基組，以及密度泛函理論的從頭計算分子動力學軟件VASP，來模擬和研究甲醛分子HCHO和甲酸分子在水溶液中的溶解情況。根據對半徑關聯函數PRDF的統計結果，可以觀察出溶質的溶解結構，以及溶劑分子之間，或者溶質與溶劑分子之間的氫鍵作用。通過水合數目可以看出氫鍵作用力隨著溫度的提升而減弱。水溶液的溫度在臨界點之上時，其結果證實了甲酸的酸解反應受到嚴重的抑制，與常溫水的結果相反。<br>使用從頭計算分子動力學軟件CPMD中基於Car-Parrinello分子動力學方法的Metadynamics方法對甲酸的反應機理進行系統的研究，包含脫水反應和脫氫反應。解離反應分別包含不同數目的分子，通過對比來研究反應中水分子所起的潛在的催化作用。除此之外，通過300K和700K這兩種不同溫度下的結果對比，來解釋超臨界水溶解中甲酸快速解離的原因。自由能曲面和自由能壘揭示了在不同環境下甲酸的主要解離途徑。<br>Solvation and chemical reactions in supercritical water are affected by a number of factors. Solvation energy, entropy, and densities are the basic thermodynamic quantities that determine the chemical equilibriums, which can be controlled by temperature and pressure. To account for these factors, static optimization leading to zero-temperature structures should be combined and compared with molecular dynamics simulation in real time. In my thesis, the solvation structures are studied in gas phase and aqueous phase, to understand the properties of solvent water and the thermal effect on the reactions.<br>The hydrated clusters of formaldehyde and formic acid in gas phase are explored computationally by density functional theory (DFT) with a basis set 6-311++G(d,p). Investigation on the structures and energies of hydrated HCHO, HCOO⁻ and HCOOH solvated by a number of water molecules is important for understanding the hydrogen bond interactions as the number of water molecules increases. Comparisons between non-dissociated and dissociated clusters of hydrated formic acid provide valuable information on the acidic dissociation of formic acid in aqueous solution.<br>The solvations of formaldehyde and formic acid in aqueous solution are simulated by density functional theory based ab initio molecular dynamics (AIMD) method with pseudopotentials and a plane wave basis set using Vienna Ab-initio Simulation Package (VASP). The pair radial distribution function is obtained to elucidate the solvation structure and the hydrogen bond interaction among solvent molecules, and between solute and solvent. The hydration number indicates the weakening of the hydrogen bond with increasing temperature. The results at the temperatures above the critical point of water show that the acid dissociation of formic acid is greatly depressed which is different from the results in ambient water.<br>The mechanisms for the dissociations of formic acid in the gas phase and in aqueous solution are studied by Car-Parrinello (CP)-based metadynamics (MTD) method, implemented in the Car-Parrinello Molecular Dynamics (CPMD) program. The two main dissociations channels of dehydration and dehydrogenation, including zero, one, two and bulk water molecules, respectively, are simulated with a biased external potential to examine the potential catalytic role of water. In addition, the thermal effects at two different temperatures are included to account for the rapid dissociation of formic acid in supercritical water. The free energy surfaces are reconstructed and the barriers are calculated to show the main dissociation pathway of formic acid in different environments.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Detailed summary in vernacular field only.<br>Chen, Qiubo.<br>Thesis (Ph.D.)--Chinese University of Hong Kong, 2012.<br>Includes bibliographical references (leaves 185-194).<br>Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web.<br>Abstract also in Chinese.<br>TITLE PAGE --- p.i<br>ABSTRCACT (ENGLISH) --- p.ii<br>(CHINESE) --- p.v<br>AKNOWLEDGEMENTS --- p.vii<br>TABLE OF CONTENTS --- p.viii<br>LIST OF FIGURES --- p.xiv<br>LIST OF TABLES --- p.xxiv<br>Chapter Chapter ONE --- Background<br>Chapter 1.1 --- Introduction of green chemistry --- p.1<br>Chapter 1.1.1 --- Green chemistry --- p.1<br>Chapter 1.1.2 --- Supercritical fluid (SCF) and supercritical water (SCW) --- p.2<br>Chapter 1.2 --- Formaldehyde and formic acid in supercritical water --- p.8<br>Chapter 1.2.1 --- Formaldehyde --- p.8<br>Chapter 1.2.2 --- Formic acid --- p.12<br>Chapter 1.3 --- Scope of this thesis --- p.17<br>Chapter Chapter TWO --- Theories and Calculation Methods<br>Chapter 2.1 --- General background --- p.19<br>Chapter 2.1.1 --- Schrödinger equation --- p.19<br>Chapter 2.1.2 --- Born-Oppenheimer approximation --- p.20<br>Chapter 2.2 --- Hartree-Fock (HF) approximation and post-Hartree-Fock (post-HF) approximation --- p.22<br>Chapter 2.3 --- Density functional theory (DFT) --- p.28<br>Chapter 2.3.1 --- Kohn-Sham (KS) scheme --- p.29<br>Chapter 2.3.2 --- Local density approximation (LDA) --- p.31<br>Chapter 2.3.3 --- Generalized gradient approximation (GGA) --- p.33<br>Chapter 2.3.4 --- Hybrid functionals --- p.34<br>Chapter 2.4 --- Ab initio molecular dynamics (AIMD) --- p.35<br>Chapter 2.4.1 --- Molecular dynamics --- p.35<br>Chapter 2.4.2 --- Ab initio molecular dynamics --- p.36<br>Chapter 2.4.3 --- Plane waves --- p.42<br>Chapter 2.4.4 --- Pseudopotentials (PP) --- p.44<br>Chapter 2.4.5 --- Periodic boundary condition (PBC) --- p.48<br>Chapter 2.5 --- Metadynamics (MTD) method --- p.48<br>Chapter 2.5.1 --- The Algorithm --- p.49<br>Chapter 2.5.2 --- Lagrangian metadynamics and the choice of V(t,s) --- p.52<br>Chapter 2.5.3 --- The choice of CVs --- p.53<br>Chapter Chapter THREE --- Structures of the Hydrated Clusters of Formaldehyde and Formic Acid<br>Chapter 3.1 --- Introduction --- p.55<br>Chapter 3.2 --- Computational details --- p.56<br>Chapter 3.3 --- Results and discussions --- p.58<br>Chapter 3.3.1 --- Studies of HCHO(H₂O)[subscript n] clusters, n = 0~4 --- p.58<br>Chapter 3.3.1.1 --- The structures of HCHO(H₂O)[subscript n] clusters, n = 0~4 --- p.58<br>Chapter 3.3.1.2 --- The energies of HCHO(H₂O)[subscript n] clusters, n = 0~4 --- p.63<br>Chapter 3.3.2 --- Studies of HCHO⁻(H₂O)[subscript n] clusters, n = 0~6 --- p.65<br>Chapter 3.3.2.1 --- The structures of HCHO⁻(H₂O)[subscript n] clusters, n = 0~4 --- p.66<br>Chapter 3.3.2.2 --- The energies of HCHO⁻(H₂O)[subscript n] clusters, n = 0~4 --- p.71<br>Chapter 3.3.2.3 --- Studies of HCOO⁻(H2O)[subscript n] clusters, n = 5 and 6 --- p.73<br>Chapter 3.3.3 --- Studies of HCOOH⁻(H2O)[subscript n] and HCOO⁻(H₃O)⁺(H₂O)[subscript n-1] clusters --- p.76<br>Chapter 3.3.3.1 --- Results of cis-HCOOH(H₂O)[subscript n] clusters and trans-HCOOH(H₂O)[subscript n] clusters, n = 0 ~ 4 --- p.76<br>Chapter 3.3.3.2 --- Results of trans-HCOOH(H₂O)[subscript n] clusters, n > 4 --- p.82<br>Chapter 3.3.3.3 --- Comparisons of non-dissociated trans-HCOOH(H₂O)[subscript n] clusters with dissociated ion pair HCOO⁻(H₃O)⁺(H₂O)[subscript n-1] clusters --- p.84<br>Chapter 3.4 --- Summary --- p.87<br>Chapter CHAPTER FOUR --- Ab initio Molecular Dynamics Studies on the Solvations of Formaldehyde HCHO and Formic Acid HCOOH in Water Solution at Different Temperatures<br>Chapter 4.1 --- Introduction --- p.90<br>Chapter 4.2 --- Computational details --- p.93<br>Chapter 4.3 --- Results and discussions --- p.94<br>Chapter 4.3.1 --- The solvation of water solution --- p.94<br>Chapter 4.3.1.1 --- The solvation of pure water solution at T = 300 K, 600 K, 700 K and 2000 K --- p.95<br>Chapter 4.3.1.2 --- The solvation of proton H⁺ in water solution at T = 300 K and 700 K --- p.101<br>Chapter 4.3.2 --- The solvation of formaldehyde HCHO in water solution at T = 300 K, 500 K, 700 K and 900 K --- p.104<br>Chapter 4.3.3 --- The solvation of formate ion HCOO⁻ in water solution at T = 300 K, 500 K, 700 K and 900 K --- p.109<br>Chapter 4.3.4 --- The solvation of formic acid HCOOH in water solution at T = 300 K, 500 K, 700 K and 900 K --- p.117<br>Chapter 4.4 --- Summary --- p.125<br>Chapter CHAPTER FIVE --- The Reactions of Formic Acid HCOOH: Insights from Car-Parrinello Based Metadynamics (MTD) Method<br>Chapter 5.1 --- Introduction --- p.128<br>Chapter 5.2 --- Computational details --- p.130<br>Chapter 5.3 --- Results and Discussions --- p.132<br>Chapter 5.3.1 --- The intrinsic rotation of a single formic acid molecule HCOOH in gas phase at T = 300 K and T = 700 K --- p.132<br>Chapter 5.3.2 --- The dehydration of formic acid in gas phase at T = 300 K and T = 700 K --- p.140<br>Chapter 5.3.2.1 --- The dehydration of a single formic acid molecule trans-HCOOH --- p.140<br>Chapter 5.3.2.2 --- The dehydration of formic acid molecule trans-HCOOH with one water molecule --- p.147<br>Chapter 5.3.2.3 --- The dehydration of formic acid molecule trans-HCOOH with two water molecules --- p.152<br>Chapter 5.3.3 --- The dehydrogenation of formic acid in gas phase at T = 300 K and T = 700 K --- p.158<br>Chapter 5.3.3.1 --- The dehydrogenation of a single formic acid molecule cis-HCOOH --- p.158<br>Chapter 5.3.3.2 --- The dehydrogenation of formic acid molecule cis-HCOOH with one water molecule --- p.163<br>Chapter 5.3.3.3 --- The dehydrogenation of formic acid molecule cis-HCOOH with two water molecule --- p.167<br>Chapter 5.3.4 --- The dissociations of formic acid in water solution at T = 300 K and T = 700 K --- p.171<br>Chapter 5.3.4.1 --- The acid dissociation of formic acid in water solution --- p.173<br>Chapter 5.3.4.2 --- The dehydration of formic acid in water solution --- p.175<br>Chapter 5.3.4.3 --- The dehydrogenation of formic acid in water solution --- p.178<br>Chapter 5.4 --- Summary --- p.181<br>References --- p.185