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Hydrogen storage remains a major technological barrier to the widespread adoption of hydrogen as an energy source. Organic polymers offer one potential route to useful hydrogen storage materials. Recently, Frechet and his coworkers described a series of hypercrosslinked polymers with high surface area and studied their surface properties and hydrogen storage capacities. McKeown and his coworkers studied a class of materials termed Polymers of Intrinsic Microporosity (PIMs) which are also based on a "hypercrosslinked" concept. We enchained N-substituted maleimide and functionalized stilbene alternating copolymers into a "hypercrosslinked system" to achieve high rigidity, high surface areas, high aromatic content and good thermal stability. Hypercrosslinked copolymers of N-(3-methylphenyl)maleimide (3MPMI), 4-methyl stilbene (4MSTBB), vinylbenzyl chloride (VBC) and divinyl benzene (DVB) were synthesized. Scanning electron micrographs (SEM) show the copolymers are porous and some examples have shown surface areas over 1200 m²/g. We have also found the incorporation of 3MPMI and 4MSTBB improves the thermal stability and raises the glass transition temperature of the copolymer. However, the incorporation of 3MPMI and 4MSTBB decreases the hypercrosslinking density and therefore causes a decrease in the copolymer surface area. The systematic study of styrene (STR) – vinylbenzyl chloride (VBC) – divinyl benzene (DVB) networks indicates that a low density of chloromethyl groups leads to a decrease in surface area. Therefore, we are continuing to investigate other monomers, such as N-substituted maleimide and functionalized stilbene containing chloromethyl groups, in order to enhance thermal stability while maintaining surface area. In order to increase the enthalpy of hydrogen adsorption and thus raise the temperature of hydrogen storage, the monomer N,N-dimethyl-N',N'-diethyl-4,4'-diaminostilbene (4,4'DASTB-3MPMI) which contains electron donating groups was incorporated into hypercrosslinked polymer particles. Hypercrosslinked polymer (4,4'DASTB-3MPMI)1.0(VBC)98.5(DVB).50 exhibits a surface area of 3257 m²/g. / Master of Science

Alternating copolymers represent a special class of copolymers in which the two comonomers copolymerize in a regular alternating sequence along the polymer chain. Of particular interest in our group are the stilbene-maleic anhydride/maleimide alternating copolymers. These copolymers possess sterically congested backbones and precisely placed functional groups arising from the strictly alternating copolymerization. The research in this dissertation is focused on the synthesis, characterization, and potential application of functionalized copolymers that contain semi-rigid alternating copolymer sequences. The fluorescence properties of a series of non-conjugated, tert-butyl carboxylate functionalized alternating copolymers were investigated. Extraordinarily high fluorescent intensity with excellent linearity was observed for the di-tert-butyl group-containing stilbene and maleic anhydride alternating copolymer in THF. We attributed the origin of the strong fluorescence to the “through space” π – π interactions between the phenyl rings from the stilbene and C=O groups from the anhydride. The fluorescence was maintained when the copolymer was deprotected and hydrolyzed and the resulting carboxylic acid-functionalized copolymer was dissolved in water at neutral pH. The tert-butyl carboxylate functionalized alternating copolymer sequences were incorporated into highly crosslinked polymer networks using suspension polymerization. After removing the tert-butyl groups by acidic hydrolysis, the surface area of the networks increased significantly. Using this facile two-step strategy, we were able to achieve nanoporous polymers with BET surface area up to 817 m2/g and carboxylic acid-functionalized surfaces. The BET surface area of deprotected polymers increased with increasing crosslinking density, and the stilbene-containing polymers showed systematically higher BET surface area than the styrene-containing polymers due to the stiffness of the alternating sequences. The resulting nanoporous polymers have potential to be employed as solid sorbents for CO2. The same tert-butyl carboxylate functionalized alternating copolymer sequences were also incorporated into microgels via miniemulsion polymerization. The miniemulsion technique ensured the successful synthesis of microgels with ~100 nm diameter using solid stilbene and maleimide monomers. The resulting tert-butyl carboxylate-containing microgels were converted into carboxylic acid-containing aqueous microgels by acid hydrolysis. These aqueous microgels showed good and reversible lead and copper ion adsorption capacities. Amine-functionalized nanoporous polymers were synthesized by the post-modification of highly-crosslinked divinylbenzene-maleic anhydride polymers. High amine-contents were achieved by covalently attaching multiamines to the acid-chloride functionalized polymer surface. The resulting polymers showed medium to high BET surface areas (up to 500 m2/g) and high CO2 capture capacities. / PHD / Copolymers are polymers that consist of two or more different monomers in the polymer chain. Research on copolymers can be traced back to the 1930s. Since the early discoveries, the research on copolymers has received considerable attention because of the ease of synthesis and the versatile properties and applications of these materials. Alternating copolymers are one of the most studied types of copolymers. In an alternating copolymer, the two different monomers arrange in a regular alternating sequence along the polymer backbone. Of special interest in our group are the alternating copolymers that contain stilbene (1,2- diphenylethylene). The stilbene-containing alternating copolymers have relatively rigid (semi-rigid) structures, which lead to unusual and interesting properties. The research described in this dissertation is focused on incorporating these semi-rigid alternating copolymers into different types of systems and studying their structure/property relationships. Three different polymeric materials and their properties were explored. Fluorescent materials can glow when irradiated by a certain wavelength of light. This property is very useful in biomedical sensing, imaging and labeling. The semi-rigid stilbene-containing alternating copolymer exhibited fluorescence with extraordinarily high intensity, solely due to the conjugation from the exact juxtaposition of molecular orbitals. This high intensity fluorescence suggests potential application as novel light-emitting materials. The increasing atmospheric CO₂ concentrations due to human activities like transportation and manufacturing have caused public concerns. Currently, liquid amine scrubbing is one of the most well established methods for CO₂ capture in industry. However, due to the solvent evaporation, degradation, and the high energy demand during the solvent regeneration, solid polymeric materials are considered as attractive alternative CO₂ capture materials. We designed two kinds of polymers based on our semi-rigid alternating copolymer sequences, and they both exhibited pores smaller than 2 nm. With the help of different functional groups designed to interact with CO₂, these polymers showed enhancement in CO₂ capture properties, and show the viability as solid sorbents for atmospheric CO₂. Heavy metal contamination in water is a severe environmental and public health problem. The recent Flint water crisis raised the public awareness of this problem. We synthesized a series of hydrogel beads with diameters in the range of 100-200 nm. The incorporation of these functional alternating copolymer sequence into the microgels led to fast and reversible adsorption of the lead and copper ions in water.

The normal operation of the endocrine (hormonal) system can be disrupted by a number of man-made and naturally-occurring chemicals, thereby affecting those physiological processes that are under hormonal control. Such substances are called endocrine disrupting compounds (EDCs). The endocrine disruption issue has alarmed the environmental authorities since the substances involved can hinder hormonal processes causing far-reaching effects on reproduction and development in current and future human and wildlife generations. Effects on some species of fish triggered worldwide concern and initiated a research scheme which is being undertaken by various organisations e.g. United States Environmental Protection Agency (USEPA), United Kingdom Environment Agency (UKEA), Oslo and Paris Commission (OSPAR), Japan Environment Agency (JEA) and World Wildlife Fund (WWF) in order to assess the effects (present and potential), point of generation, levels of contamination and exposure limits. The findings showed that most of the oestrogens are produced by humans and animals and get discharged into river streams mainly through sewage effluents. Fish in particular have been found to be affected the most even when the oestrogenic levels in water are very low. The probability of future European legislation to eliminate hormonally active compounds from wastewaters suggests that new and alternative methods should be developed for their removal. In this work, the adsorption of 17ß-oestradiol (E2) and 17a-ethinyl oestradiol (EE2) onto several granular activated carbons and Hypersol-Macronet hypercrosslinked polymers was investigated by batch experiments after a low level detection system had been developed using Gas Chromatography Mass Spectrometry (GC/MS). Equilibrium experiments were carried out for all adsorbents to quantify the sorption capacity for E2 and EE2. For better assessment of the sorbents performance, their physical properties such as surface area, average pore diameter and micropore volume and chemical structure were characterised by N2 adsorption experiments, scanning electron microscopy (SEM), FTIR spectroscopy, elemental analysis, sodium capacity determination, pH titration, proton binding curves and zeta potential measurements. Adsorption isotherm data were fitted to the Langmuir and Freundlich equations. Activated carbons were found to be preferable to Hypersol-Macronet hypercrosslinked polymers for adsorption purposes. The adsorption of oestrogens appears to be controlled by hydrophobic interactions. Kinetic experiments were performed with different size ranges of adsorbents at different concentrations and the results were analysed by a particle diffusion model. It was found that concentration did not seem to influence the kinetics of the oestrogen sorption whereas the particle size of the adsorbents influenced the adsorption rate of both molecules. The particle diffusion model seemed to fit the data collected for the adsorption rate of 17B-oestradiool onto the adsorbents but gave a poor fit for most of the data collected for 17a-ethinyl oestradiol.

Nanoporous organic polymers, including hypercrosslinked polymers (HCPs), covalent organic frameworks (COFs), polymers of intrinsic microporosity (PIMs), and conjugated microporous polymers (CMPs) etc., are considered good candidates for potential gas storage and gas separation applications. Porosities and surface areas of a series of semirigid alternating copolymers, which contained tert-butyl carboxylate-functionalized stilbene or tert-butyl carboxylate-functionalized styrene, and maleic anhydride or tert-butyl carboxylate-functionalized phenyl maleimide, were investigated using nitrogen sorption/desorption isotherms at 77 K and molecular simulations. These alternating copolymers were found to have Brunauer-Emmett-Teller (BET) surface areas in the range of 20-40 m2/g. Surface areas of these alternating copolymers increased as the steric crowding of the polymer backbone increased, which was the result of introducing extra phenyl rings and/or N-phenyl substituent maleimide units. Surface areas were found to increase as the persistence length increased. A series of HCPs containing functionalized stilbene and N-substituted phenyl maleimide were synthesized via free radical suspension polymerization. The incorporation of these functionalized, chain stiffening, Tg enhancing comonomers raised the Tgs of precursor polymers before they were crosslinked. Surface areas of these HCPs, obtained from nitrogen adsorption/desorption isotherms at 77 K, were up to 1058 m2/g. However, the surface areas of these HCPs were systematically lower than the controls. The high rigidity of the polymer backbone, which was the result of incorporating Tg enhancing comonomer, likely affected the chain mobility of the precursor polymer, decreased the efficiency of post-crosslinking reactions, and thus resulted in lower surface areas. Amine-functionalized styrene/stilbene polymers were prepared via free radical polymerization or post-modification. Amine-containing silica-based sorbents were prepared using the impregnation method. Sorption of CO2 by these materials was tested using TGA and compared with control samples. Both high amine content and certain levels of surface area were found to be important for a sorbent to achieve high CO2 uptake. Highest CO2 uptake (12 wt%) under our testing condition in these materials was achieved by an amine-containing silica sorbent. / Ph. D.