| Recently, hydrogels consisting of nanoparticles and polymers have attracted significant attention due to their potential in biomedical applications. Similarly, researchers are intrigued by films made of nanoparticles and polymers due to their application in multifunctional coatings. The desired properties of hydrogels and films are dominated by the interactions within the system. Therefore, it is of great importance to fully understand the interactions within hydrogels and thin films, in order to engineer desired properties.;The first part of this thesis explores the properties of hydrogels. Hydrogels of the synthetic clay laponiteRTM and laponiteRTM -poly (ethylene oxide) (PEO) have long been studied as model systems to understand the fundamentals of colloid-polymer systems and their application in biomedical fields. However, the interactions between laponiteRTM and PEO remain not fully understood, and moreover, there is limited information on the fundamental properties of the system at physiologically relevant conditions. The first part of this thesis explores the properties of the system at physiologically relevant conditions with the presence of phosphate buffered saline, as well as investigates the interactions within laponiteRTM-PEO hydrogel. The results show that the elastic modulus of hydrogels systems increases dramatically, in some cases by one order of magnitude, after immersing gels in phosphate buffered saline, probably as a result of the formation of a house-of-card structure.;The second part of this thesis presents the auto-stratification of thin films. Conventionally, multifunctional thin films such as anti-fouling coatings are produced by multi-step deposition. However, a single-step deposition process will improve manufacturing efficiency and lower production cost. The second part of this thesis presents a method to produce multifunctional coating through one single step auto-stratification. By investigating the interactions between silica nanoparticles and polystyrene nanoparticles, as well as the morphologies of resulting films, the results show that auto-stratification is affected by the humidity of manufacturing environment, the Peclet number of the particles, and the hydrophobicity of the particle surfaces. The production parameters are optimized, and it is shown that multifunctional thin films can be produced through single-step deposition by altering these parameters. |
