Thesis (M.Ch.E.)--University of Delaware, 2006. / Principal faculty advisor: Eric W. Kaler, College of Engineering. Includes bibliographical references.

Thesis (Ph. D.)--University of Washington, 2001. / Vita. Includes bibliographical references (leaves 143-148).

Thesis (Ph. D.)--Lehigh University, 2003. / Includes vita. Includes bibliographical references (leaves 164-170).

Thesis (Ph. D.)--University of North Texas, May, 2008. / Title from title page display. Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2010. / Printout. Includes bibliographical references (leaves 97-101). Also available on the World Wide Web.

Thesis (Ph. D.)--Florida State University, 2006. / Advisor: Wei-Chun Chin, Florida State University, College of Engineering, Dept. of Chemical and Biomedical Engineering. Title and description from dissertation home page (viewed July 5, 2006). Document formatted into pages; contains xiii, 118 pages. Includes bibliographical references.

Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 59-61). Also available on the World Wide Web.

膠體顆粒吸附在油水介面的現象最近幾年引起極大的關注。一方面，受限在油水介面的膠體顆粒可以用作一個很好的模型體系來研究一些基本物理問題，例如二維結晶，擠壓以及其它相轉變問題。另一方面，在許多工業產品和處理過程中，例如食品，抗沫劑製備，以及原油乳液處理中膠體顆粒在油水介面的行為扮演著極為重要的角色。 / 微凝膠，一種軟膠體顆粒，也可以作為乳化劑用來穩定製備乳液。微凝膠在許多方面和普通膠體顆粒有著相同的行為。但是，微凝膠顆粒，作為一種三維交聯的高分子網狀鏈，在良性溶劑裡會膨脹。之前已經有報導明確指出這種微凝膠顆粒可以用來穩定的乳液。並且這些乳液的穩定性可控，此性質在小分子乳化劑和普通膠體顆粒體系是無法實現的。但是，這些微凝膠顆粒製備的乳液的穩定以及不穩定的作用機制至今尚有許多爭論。具體來說，這些微凝膠是如何吸附到油水面，什麼因素控制著這些吸附行為，微凝膠在油水介面如何行為，吸附在油水介面的微凝膠如何動態的回應外界條件的改變，統統不清楚。 / 本論文首先旨在深入瞭解微凝膠在油水介面的動態行為，然後用這些微凝膠穩定的乳液作為範本製備出多功能材料。本論文一共包括八部分，這八部分全部圍繞著微凝膠在油水介面的行為而展開。第一部分將介紹微凝膠應用在油水介面的研究已經取得的進展。第二部分將介紹彎曲的油水介面以及本論文主要用到的儀器。在第三部分，我們將會介紹微凝膠的製備與表徵。第四部分，我們集中於微凝膠是如何吸附到油水介面。我們發現微凝膠的柔軟，稀鬆，以及可變形決定了微凝膠的吸附過程。第五部分，我們探討為什麼油水介面動態張力在微凝膠的相轉變溫度附近有個最低值。通過對介面張力，溫度還有時間進行三維作圖，我們發現介面張力在微凝膠相轉變溫度附近(308.1K) 存在一個峰穀。這個峰谷的形成是由微凝膠的變形性以及它們之間相互作用所導致的。這些微凝膠吸附在油水介面之後形成一個新的微凝膠膜隔離開水與油，這層微凝膠險主導著油水介面的性質。第六部分，基於以上理解，我們在相轉變溫度附近創建了一個微凝膠未鋪滿的油水介面來研究微凝膠顆粒在一個受限的環境下的溫敏性行為。降低溫度，微凝膠在油水介面經歷一個極慢的舒張過程。但是升高溫度，微凝膠並沒有塌縮。第仁部分，我們首先應用微凝膠作為唯一穩定劑製備了一種高內相乳液，然後以此乳液為範本製備了多功能材料。最後一部分，縱觀全文，我們的結論是微凝膠的變形性以及它們之間的相互作用對於微凝膠在油水介面的行為起著非常重要的角色:包括微凝膠在油水介面的吸附行為，微凝膠在油水介面的溫敏性行為，油水介面的流變性能以及多功能材料的性能。 / The adsorption phenomena of colloidal particles at the liquid-liquids interfaces have received tremendous interests in recent years. On the fundamental side, interest stems from the fact that colloidal particles confined to the interfaces can serve as an elegant system for fundamental studies of physical processes, such as two-dimensional crystallization, jamming and other phase transitions. On the practical side, interest arises as a result of demonstrated importance of the behavior of colloidal particles at the interfaces for applications in many industrial products and processes such as the production of food, anti-foam formulations, and crude oil. / In recent years, soft particles, like microgels are also employed as emulsifiers for making emulsions. These microgel particles resemble colloidal particles in many aspects. However, structurally, microgel particles constitute a three-dimensional covalently crosslinked network and can swell up in good solvents. It has been reported that emulsions stabilized by these soft microgel particles can offer an unprecedented degree of control of emulsion stability, well beyond what can be achieved by using small molecular surfactants or conventional particles. However, the stabilization and destabilization mechanism involving such soft and deformable microgels is still a matter of debate. Specifically, how microgels adsorb onto the oil-water interfaces; what parameters control the microgel adsorption; how these microgels behave at the interfaces; and how these microgels respond to environmental triggers after adsorption, are unclear. / This thesis aims at first gaining a fundamental understanding of the microgels dynamic behaviors at the oil-water interfaces, and then using this system to fabricate functional materials. This thesis contains eight parts; all of them are connected with soft microgels at the oil-water interfaces. The first part of this thesis introduces the soft microgels’ performance at the oil-water interfaces. The second part focuses on the curved oil-water interfaces and the instrument we will use in this thesis. In the third part, we will present the preparations and characterizations of microgels. The fourth part addresses the microgels adsorption behaviors at the oil-water interfaces. Our results clearly show that deformability of microgel particles plays a vital role in their adsorption behaviors at the oil-water interfaces. In the fifth part, we discuss why interfacial tension (γ) exhibits a minimum in the vicinity of PNIPAM-related microgel volume phase transition temperature (VPTT). Our results suggest that, this observed minimum can be attributed to highest deformability of microgels around VPTT as well as the interactions among the adsorbed microgels. Moreover, our results reveal that unlike conventional solid particles, the adsorbed microgels are not wetted by both oil and water. On the contrary, they will form an intruding microgel layer separating the oil and water phases, which ultimately dominates the oil-water interfacial properties. Based on the above understanding, in the sixth part, we create microgels partially covered oil-water interfaces, and investigate the microgels thermal behaviors under a confined condition. Our results show that microgels undergo an extremely slow swelling process at the oil-water interfaces. In addition, microgels would not collapse upon heating. In the seventh part of this thesis, we present the preparation of high internal phase emulsions (HIPEs) by solely using soft microgels as emulsifiers. Furthermore, we demonstrate that these microgels-stabilized HIPEs can be good templates for the preparation of hierarchical porous functional materials. Based on our investigations, in the final part, we summary the importance of microgel deformability and their interactions on microgels behaviors at the oil-water interfaces: including their adsorption dynamics, thermal-responsive behaviors, oil-water interfacial rheology properties and functional materials properties. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Li, Zifu. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese. / 摘要 --- p.I / ABSTRACT --- p.III / ACKNOWLEDGEMENT --- p.V / TABLE OF CONTENTS --- p.VII / Chapter CHAPTER 1 --- INTRODUCTION AND BACKGROUND --- p.1 / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.1.1 --- Surfactant-stabilized emulsions --- p.1 / Chapter 1.1.2 --- Particle-stabilized emulsions --- p.3 / Chapter 1.2 --- Microgels as particulate emulsifiers in Pickering Emulsions --- p.6 / Chapter 1.2.1 --- Literature survey of microgels at interfaces --- p.7 / Chapter 1.2.2 --- Discussions and conclusions --- p.16 / Chapter 1.3 --- Theme of this thesis --- p.18 / Chapter 1.4 --- References and Notes --- p.19 / Chapter CHAPTER 2 --- THE FUNDAMENTALS OF CURVED OIL-WATER INTERFACE --- p.21 / Chapter 2.1 --- Introduction --- p.21 / Chapter 2.2 --- Pendant drop tensiometer --- p.22 / Chapter 2.3 --- The dynamic interfacial tension --- p.26 / Chapter 2.3.1 --- Two surfactant adsorption mechanisms --- p.27 / Chapter 2.4 --- Investigation of one single interface --- p.29 / Chapter 2.4.1 --- Pure heptane-water interface --- p.30 / Chapter 2.4.2 --- Heptane-BSA protein solution interface --- p.35 / Chapter 2.5 --- Dilatation rheology --- p.41 / Chapter 2.6 --- Conclusions --- p.42 / Chapter 2.7 --- References and Notes --- p.43 / Chapter CHAPTER 3 --- SYNTHESIS AND CHARACTERIZATION OF PNIPAM-RELATED MICROGELS --- p.45 / Chapter 3.1 --- Introduction --- p.45 / Chapter 3.2 --- Microgels preparation and characterization --- p.56 / Chapter 3.2.1 --- Preparation of microgel samples used in this thesis --- p.57 / Chapter 3.2.2 --- Microgels characterization --- p.59 / Chapter 3.3 --- Conclusions --- p.63 / Chapter 3.4 --- References and Notes --- p.63 / Chapter CHAPTER 4 --- MICROGEL ADSORPTION BEHAVIORS AT THE OIL-WATER INTERFACES: THE KINETIC STUDY --- p.65 / Chapter 4.1 --- Introduction --- p.65 / Chapter 4.2 --- Results and discussions --- p.67 / Chapter 4.2.1 --- The effect of microgel concentration: below VPTT --- p.68 / Chapter 4.2.2 --- Microgel concentration effect on dynamic interfacial tension: above VPTT of microgels --- p.73 / Chapter 4.2.3 --- Temperature effect on dynamic interfacial tension well above VPTT --- p.78 / Chapter 4.2.4 --- Diffusion controlled process --- p.81 / Chapter 4.2.5 --- Kinetic controlled process --- p.85 / Chapter 4.3 --- Conclusions --- p.93 / Chapter 4.4 --- References and Note --- p.95 / Chapter CHAPTER 5 --- ANOMALOUS INTERFACIAL TENSION VALLEYS DURING THE VOLUME PHASE TRANSITION OF PNIPAM MICROGELS AT THE OIL-WATER INTERFACE --- p.96 / Chapter 5.1 --- Introduction --- p.96 / Chapter 5.2 --- The interfacial tension valleys --- p.97 / Chapter 5.3 --- Discussions --- p.106 / Chapter 5.4 --- Conclusions --- p.115 / Chapter 5.5 --- References and Notes --- p.115 / Chapter CHAPTER 6 --- THE THERMAL BEHAVIOR OF MICROGELS CONFINED AT THE OIL-WATER INTERFACES: REVERSIBLE OR IRREVERSIBLE? --- p.117 / Chapter 6.1 --- Introduction --- p.117 / Chapter 6.2 --- Microgels thermal behaviors confined at interfaces --- p.118 / Chapter 6.3 --- Conclusions --- p.137 / Chapter 6.4 --- References and Notes --- p.138 / Chapter CHAPTER 7 --- FUNCTIONAL MATERIALS FROM MICROGELS AT INTERFACES --- p.139 / Chapter 7.1 --- High internal phase emulsions (HIPEs) --- p.139 / Chapter 7.2 --- Microgels stabilized HIPEs --- p.140 / Chapter 7.2.1 --- Preparations --- p.140 / Chapter 7.2.2 --- Characterizations --- p.141 / Chapter 7.3 --- Materials from microgels stabilized emulsions --- p.144 / Chapter 7.3.1 --- Porous membranes --- p.144 / Chapter 7.3.2 --- Hierarchical porous materials --- p.145 / Chapter 7.4 --- Conclusions --- p.146 / Chapter 7.5 --- References and Notes --- p.147 / Chapter CHAPTER 8 --- OVERVIEW OF MICROGELS AT INTERFACES --- p.148 / Chapter 8.1 --- Summary of microgels at interfaces --- p.148 / Chapter 8.2 --- Outlook and further experiments --- p.150 / CURRICULUM VITAE --- p.152

固體表面吸附高分子常被用於控制介面的物化特性，例如，膠體粒子的位阻穩定或者絮凝作用，表面改性以及生物增容作用，表面潤滑和耐磨性能。在分子水準上，促進高分子吸附作用的機制包括：范德華作用，氫鍵相互作用，靜電作用和含表面結合位點的特殊相互作用。近年來，表面改性的研究熱點集中於尋找合適的方法，包括精確控制聚電解質刷的合成以及高分子吸附的選擇。然而，對於改性後的表面間相互作用的直接測定顯得相對滯後。這其中的原因主要是因為它們之間的相互作用太弱，無法用常規儀器測定。 / 本篇論文的主要目的是直接定量地測定固體表面吸附高分子和接枝完聚電解質高分子刷之後於水溶液中的弱相互作用。第一章主要介紹固體表面如膠體粒子間的相互作用，著重細緻討論了排空力，位阻排斥力，振盪結構力以及聚電解質刷所引起的作用力。在第二章中，我們探討了自行搭建的單粒子力學顯微鏡全內反射顯微鏡的歷史，發展及其原理。第三章闡述了表面改性中具體的化學方法。 / 第四章中，我們用直徑為5微米的聚苯乙烯小球作為探針，利用全內反射顯微鏡測定了不同的鹽溶液（氯化鈉和高氯酸鈉）對陽離子聚電解質刷（聚甲基丙烯醯氧乙基三甲基氯化銨）構象的影響。實驗結果顯示，高氯酸根與聚電解質刷的相互作用除了電荷遮罩作用外，還與聚電解質刷上的季銨鹽離子有強烈的離子配對作用能引起聚電解質刷失水造成“疏水折攏“。 / 在第五章中，我們主要運用全內反射顯微鏡研究了pH及離子強度變化對另一種陽離子聚電解質刷聚甲基丙烯酸二甲氨乙酯的溶脹作用的影響。對包覆了分子量為2000 g/mol的聚乙烯亞胺的聚苯乙烯微球以及表面改性了該種聚電解質刷之間的相互作用進行了直接測定。研究結果表明，聚電解質刷的鏈長，pH以及鹽離子強度對其作用影響很大。本實驗主要研究了兩種鏈長的聚電解質刷在溶液中的作用。對於較短的鏈長，在pH為4.2時，雙電層中的擴散層交疊排斥作用占主導且作用機理符合傳統的DLVO理論。但是，當pH逐步下降時，長程吸引作用開始出現。對於溶脹的較長鏈聚電解質刷，在高pH及低鹽離子強度時，其相互作用符合DLVO理論。然而，當降低pH或者提高鹽離子濃度時，作用勢能偏離DLVO理論，具體表現為：pH 4.0時為純靜電排斥作用，pH 3.6時出現弱吸引作用，pH 3.0時吸引變強，以上過程可循環往復。 / 第六章主要利用全內反射顯微鏡測定了一個微球與平整玻璃表面之間由聚環氧乙烷水溶液引起的相互作用。我們的結果展示了聚環氧乙烷吸附在兩固體表面上所引起的作用具有很強的濃度依賴性：在低濃度時，由靜電層排斥作用占主導；在較高濃度時，由聚合物橋接引起的長程吸引開始出現；在更高濃度時，我們檢測到額外的排斥作用出現，並推測是由於位阻排斥作用而非排斥的排空力作用引起；在繼續增大濃度後，我們觀察到了振盪結構力。 / Adsorption of polymers onto solid surfaces has often been used to control interfacial properties including steric stabilization or flocculation, surface modification and biocompatibilization, and lubrication as well as wear properties. In the molecular level, the mechanisms promoting polymer adsorption include attractive van der Waals forces, dipolar of hydrogen-bonding type attraction, electrostatic, or specific chemical interactions with surface binding sites. While a lot of efforts have been devoted in recent years to optimize the surface modification by synthesis of different types of polyelectrolyte brushes or polymers for adsorption, there have been few reports aimed at directly measuring the interaction forces between surfaces covered by the polymers and polyelectrolyte brushes in solution. This is not surprising because the forces of the interaction are extremely weak. / This thesis aims to directly and quantitatively study on the weak interaction between solid surfaces with adsorbed polymers and polyelectrolyte brushes in aqueous solutions. In the first chapter, the interactions between solid surfaces such as the colloidal particles are introduced. Specifically, forces such as depletion, steric repulsion, oscillatory structural forces and polyelectrolyte brushes induced forces are discussed in details. In the second chapter, we discuss about the historical background, development and principles of our recently home-made single particle force microscopy, Total Internal Reflection Microscopy (TIRM). The third chapter focuses on the synthesis of polymer brushes on solid surfaces. In this chapter, various chemical modification methods are covered. / In the fourth chapter, the conformational behavior of polyelectrolyte brushes in different electrolyte environments (NaCl and NaClO₄) has been investigated by directly measuring the interaction energy profile between a 5 m diameter polystyrene (PS) particle with a cationic poly (2-(methacryloyloxy)ethyl trimethylammonium chloride) (PMETAC) brush-grafted surface using TIRM. Our results show that ClO₄⁻ anions show strong ion paring with the quaternary ammonium groups on the polymer brushes, leading to what have called hydrophobic collapse where dehydration occurs in addition to pure charge screening. / In the fifth chapter, we applied TIRM to study the pH and ionic strength dependent swelling behavior of surface-grown cationic polyelectrolyte brush, poly((2-dimethylamino) ethyl methacrylate) (PDMAEMA). As can be shown by direct force measurements between PDMAEMA grafted glass surface and PEI (polyethylene, Mw: 2000 g / mol) coat PS particle, the interactions are strongly affected by length of polyelectrolyte brush, pH values and salt concentrations. Polymer brushes with two different lengths are studied. For short polymer brushes, the interactions at pH 4.2 are dominated by repulsive forces originating from diffuse layer overlap, in line with the classical theory of Derjaguin, Landau, Verwey, and Overbeek (DLVO). However, with decreasing the pH values, a long-range attraction sets in. For swollen and longer polymer bushes, the interactions are in a good agreement with the DLVO theory at high pH and low ionic strength. However, upon decreasing the pH value or increasing salt concentration, the inte actions show a significant deviation from DLVO theory. Specifically, the interaction between the particle and brushes-grafted surface can be switched reversibly between pure repulsion at pH 4.0, medium attraction at pH 3.6 and strong attraction at pH 3.0. / In the sixth chapter, TIRM was used to directly measure the interaction between a microsphere and a flat hydrophilic surface in the presence of polyethylene oxide (PEO) solution. Our results show that the PEO adsorption onto the solid surfaces is highly concentration dependent: at low polymer concentration, the interactions between two surfaces in the presence of PEO are dominated by repulsive forces originating from diffuse layer overlap; at intermediate polymer concentration, a long range and weak attraction sets in. We attribute the forces to the polymer bridging. While at high polymer concentration, an additional repulsive force is detected, and we believe this is not originated from repulsive depletion. But rather, our results suggest that this may due to the steric repulsion. Finally, at very high concentration, oscillatory structural force is detected. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Wei, Xiaoling. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references. / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstracts also in Chinese. / 摘要 --- p.i / Abstract --- p.iii / Acknowledgement --- p.vi / Chapter Chapter 1. --- Background and Introduction --- p.1 / Chapter 1.1. --- Introduction to colloidal particles interaction --- p.1 / Chapter 1.2. --- Polymer induced forces in colloidal systems --- p.3 / Chapter 1.2.1. --- Steric repulsion --- p.3 / Chapter 1.2.2. --- Bridging interaction and depletion interaction --- p.4 / Chapter 1.2.3. --- Oscillatory structural forces --- p.7 / Chapter 1.2.4. --- Polyelectrolyte brushes induced forces --- p.9 / Chapter 1.3. --- Discussions --- p.11 / Chapter 1.4. --- Works in this thesis --- p.12 / Chapter 1.5. --- References and Notes --- p.13 / Chapter Chapter 2. --- Total Internal Reflection Microscopy (TIRM) --- p.16 / Chapter 2.1. --- Introduction --- p.16 / Chapter 2.2. --- Evanescent wave and total internal reflection --- p.17 / Chapter 2.3. --- Apparatus --- p.21 / Chapter 2.4. --- Data analysis --- p.25 / Chapter 2.5. --- Noise Analysis and Removal --- p.28 / Chapter 2.6. --- Interaction potentials; theory and TIRM measurement results --- p.30 / Chapter 2.7. --- References and Notes --- p.32 / Chapter Chapter 3. --- Surface Initiated Polymerization --- p.35 / Chapter 3.1. --- Introduction --- p.35 / Chapter 3.2. --- Living anionic polymerization --- p.36 / Chapter 3.3. --- Controlled radical polymerization methods --- p.36 / Chapter 3.3.1. --- Nitroxide-mediated polymerization --- p.37 / Chapter 3.3.2. --- Reversible addition-fragmentation chain transfer (RAFT) polymerization --- p.39 / Chapter 3.3.3. --- Atom transfer radical polymerization (ATRP) --- p.42 / Chapter 3.4. --- Experimentals --- p.46 / Chapter 3.5. --- Properties and applications of polymeric brushes --- p.48 / Chapter 3.6. --- References and Notes --- p.49 / Chapter Chapter 4. --- Ion-Induced Hydrophobic Collapse of Surface-Confined Polyelectrolyte Brushes Measured by Total Internal Reflection Microscopy --- p.56 / Chapter 4.1. --- Introduction --- p.56 / Chapter 4.2. --- Experimental Section --- p.58 / Chapter 4.3. --- Results and Discussion --- p.63 / Chapter 4.4. --- Conclusions --- p.75 / Chapter 4.5. --- References and Notes --- p.76 / Chapter Chapter 5. --- Direct Measurement of the Interactions between Polyelectrolyte Brush and Microsphere Studied by Using Total Internal Reflection Microscopy (TIRM) --- p.79 / Chapter 5.1. --- Introduction --- p.79 / Chapter 5.2. --- Experimental Section --- p.82 / Chapter 5.3. --- Results and Discussion --- p.89 / Chapter 5.4. --- Conclusions --- p.104 / Chapter 5.5. --- References and Notes --- p.105 / Chapter Chapter 6. --- Interactions between Solid Surfaces Mediated by Polyethylene Oxide (PEO): Concentration Effects --- p.109 / Chapter 6.1. --- Introduction --- p.109 / Chapter 6.2. --- Experimental Section --- p.112 / Chapter 6.3. --- Results and Discussion --- p.114 / Chapter 6.4. --- Conclusions --- p.126 / Chapter 6.5. --- Reference and Notes --- p.126 / Chapter Appendix --- p.130 / Chapter Experimental Section for the Swelling Ratio Calculation of PDMAEMA Brushes --- p.130 / Chapter References and Notes --- p.137 / List of Publications --- p.138 / Conferences and Symposiums Attended --- p.140

Thesis (Ph. D.)--University of North Texas, Aug., 2009. / Title from title page display. Includes bibliographical references.