Nanoscience and Nanotechnology Commons^™

Inherently Porous Atomically Thin Membranes For Gas Separation, Harpreet Atwal

Electronic Thesis and Dissertation Repository

Membranes made from atomically thin materials promise hundreds of times higher production rates than conventional polymer membranes for separation applications. Graphene is impermeable to gases but becomes selectively permeable once pores are introduced into it but creating trillions of nanopores over large areas is difficult. By instead choosing an inherently porous two-dimensional material with naturally identical pores repeated at high density, we may circumvent this challenge. In this work, we explore the potential of two candidate materials, 2D polyphenylene and graphdiyne. We synthesize cyclohexane-m-phenylene, a monomer of 2D polyphenylene. We then develop an atomic force microscopy technique for measuring the …

Synthesis Of Vo2/Poly(Mma-Co-Dmemuabr) Antimicrobial/Thermochromic Dual-Functional Coating And Reactivity Ratios Study, Yixian Liu

Electronic Thesis and Dissertation Repository

Antimicrobial/thermochromic dual-functional coatings were successfully synthesized via UV-curing. The quaternary ammonium compound (QAC) N,N-dimethyl-N-{2-[(2-methylprop-2-enoyl)oxy]ethyl}undecane-1-aminium bromide (dMEMUABr) was synthesized and copolymerized with methyl methacrylate (MMA) for antimicrobial properties. Vanadium oxide (VO₂) nanoparticles were evenly dispersed within the coating, providing thermochromic properties. The dual-functional coating showed high luminous transmittance (T_lum(25°C) =36.1 %) and solar energy modulation ( T_sol=5.8 %). 90.3 % of bacteria reduction was observed against Escherichia coli within 24 h contact. To further understand the sequence distribution of the copolymer poly(MMA-co-dMEMUABr), the reactivity ratios of MMA and dMEMUABr monomer were studied and compared under thermal …

A Ph-Sensitive Delivery System For The Prevention Of Dental Caries Using Salivary Proteins, Yi Zhu

Electronic Thesis and Dissertation Repository

Dental caries remains one of the most common chronic diseases worldwide. Salivary proteins such as histatins have demonstrated biological functions directly related to tooth homeostasis and prevention of dental caries. However, histatins are susceptible to the high proteolytic activities in the oral environment. Therefore, pH-sensitive chitosan nanoparticles (CNs) have been proposed as potential carriers to target major oral diseases that occur under acidic conditions (e.g. dental caries and dental erosion). Four different types of chitosan polymers were investigated and the optimized CNs successfully loaded histatin 3 and released it selectively under acidic conditions. Through loading the survival time of histatin …

Studies On Nanocomposite Coating Produced By Laser-Assisted Process To Prevent Silicone Hydrogels From Bio-Fouling, Vishnuvardhana Wuppaladhodi

Electronic Thesis and Dissertation Repository

In this thesis, silver nanoparticles incorporated into polyvinylpyrrolidone (PVP) were deposited on silicone hydrogel to improve the hydrophilicity of the silicone hydrogel and prevent the growth of bacteria. Two different processes were employed to produce Ag nanoparticles: (1) Process-A is a photochemical reduction; (2) Process-B is laser ablation in liquid. Following that, MAPLE process was employed to deposit the Ag-PVP nanocomposites on the surface of silicone hydrogel. A solid-state pulsed laser (Nd:YAG) with a wavelength of 532 nm at a fluence of 50.4 mJ/cm² was used in the MAPLE system to deposit Ag-PVP nanocomposite coating. Our results indicate that …

Engineered Quantum Dots For Eva Nanocomposite Films And Tio2 Photocatalysts, Md Abdul Mumin

Electronic Thesis and Dissertation Repository

Light absorbing inorganic nanoparticles in transparent plastics such as poly(ethylene-co-vinyl acetate) (EVA) are of enormous interest in emerging solar materials, including photovoltaic (PV) modules and commercial greenhouse films. Quantum dots (QDs) have the potential to absorb UV light and selectively emit visible light. However, how to stabilize the QDs for long product life spans without "blinking" while enabling their easy integration into polymer systems is lacking. This work examines different approaches for loading mesoporous silica encapsulated QDs into EVA polymer films which can control plant growth in greenhouses or enhance PV panel efficiencies.

Highly luminescent CdS and CdS-ZnS core-shell QDs …