Polymers rich in primary amine groups are proposed to be effective adsorbents for the reversible adsorption of CO2 from moderately dilute gas streams (10% CO2) and ultra-dilute gas streams (e.g. ambient air, 400 ppm CO2), with their performance under ultra-dilute conditions being competitive with or exceeding the state-of-the-art adsorbents based on supported poly(ethyleneimine) (PEI). The CO2 adsorption capacity (mmol CO2/g sorbent) and amine efficiency (mmol CO2/mmol amine) of linear poly(allylamine) (PAA), cross-linked poly(allylamine) prepared by post-polymerization crosslinking with epichlorohydrin (PAAEPI), and branched poly(allylamine) prepared by branching of poly(allylamine) with divinylbenzene (PAADVB) are presented here and compared with state-of-the-art adsorbents based on supported PEI, specifically branched and linear, low molecular weight PEI. Silica mesocellular foam, MCF, serves as the support material for impregnation of the amine polymers. In general, branched polymers are found to yield more effective adsorbents materials. Overall, the results of this work show that linear PAA, cross-linked PAAEPI, and branched PAADVB are promising candidates for solid adsorbents with high capacity for CO2.

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New vigorous regulations have been established for decreasing the allowable formaldehyde emissions from nonstructural wood based composites. Two main sources of formaldehyde emission in non-structural wood based composites are adhesive and wood. Adhesives are quite well known and great efforts have been conducted to decrease their formaldehyde content; however formaldehyde emission from wood has received little attention and it is not completely understood. Wood-borne formaldehyde emission exists in a complex equilibrium in wood matrix. The reaction between formaldehyde and wood hydroxyl groups/water can hinder the complete formaldehyde extraction. In order to have a complete formaldehyde extraction, a stronger nucleophile than hydroxyl and water groups is needed. In this study cross-linked poly (allylamine) (PAA) beads were synthesized and used as a strong nucleophile to extract all the biogenic and synthetic free-formaldehyde within the woody matrix of never-heated and heat-treated Virginia pines; the results were compared to simple water extraction. A new formaldehyde capturing device was also developed using a serum bottle. Results showed that there was no advantage of using PAA beads over simple water extraction for extracting woody matrix free-formaldehyde. This means that simple water extraction can extract all the free-formaldehyde from the woody matrix. It was also found that thermal treatment resulted in generating more wood-borne formaldehyde. The other important finding was the new developed formaldehyde capturing device. The device was very promising for detecting wood-borne formaldehyde from very small pieces of wood (5-70 mg) and can be very useful in future studies. / Master of Science

In the first part of this study, frictional and normal forces in aqueous solutions were measured between a glass particle and oligopeptide films grafted from a glass plate. Homopeptide molecules consisting of 11 monomers of different amino acids were each "grafted from" an oxidized silicon wafer using microwave-assisted solid phase peptide synthesis. Oligopeptides increased the magnitude of friction compared to a bare hydrophilic silicon wafer. Friction was a strong function of the nature of the monomer unit and was lower for hydrophilic films. There was a strong adhesion and therefore friction between surfaces of opposite charges. Changes in adhesion and friction depended on the hydrophobicity and electrostatic forces: hydrophobic films and oppositely charged films produced high friction, whereas hydrophilic and like-charges produced low friction. Friction was lower in phosphate buffered saline than in pure water due to the screening of the double layer attraction for oppositely charged surfaces and additional lubrication by hydrated salt ions. We also investigated antimicrobial action of poly (allyl amine) (PA) when covalently bonded to glass. Glass surfaces were prepared by a two-step procedure where the glass was first functionalized with epoxide groups using 3-glycidoxypropyltrimethoxy silane (GOPTS) and then exposed to PA to bind via reaction of a fraction of its amine groups. Antibacterial properties of these coatings were evaluated by spraying aqueous suspensions of bacteria on the functionalized glass slides, incubating them under agar, and counting the number of surviving cell colonies. The PA film displayed strong anti-microbial activity against both Gram-positive and Gram-negative bacteria. Films that were prepared by allowing the PA to self assemble onto the solid via electrostatic interactions were ineffective antimicrobials. Such films had an insufficient positive charge and did not extend far from the solid. Thus we found that antimicrobial activity was correlated with a combination of the ability of the polymer chain to extend into solution and a positive surface potential. / Ph. D.