Nanoscale Characterization and Mechanism of Electroless Deposition of Silver Metal

This dissertation is an investigation of the nanoscale characteristics and mechanism of electrolessly deposited silver metal seeded by gold nanoparticles. The process of growing seed-nanoparticles on a polymer surface was studied. Several bifunctional amines and organic reducing agents were used to explore how these chemical factors affect the size and distribution of gold nanoparticles formed at the interface. The nanoparticles were characterized by transmission electron microscopy (TEM) and high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). An electroless deposition (ED) bath developed by Danscher was selected to study electroless deposition of silver in detail. The chemical species in the bath were varied to determine how concentration, nature of the carboxylate buffering species, and the presence and absence of gum arabic affect the morphology of silver metal formed by ED and the overall rate of deposition at the surface. The kinetics of deposition using the Danscher bath was studied in detail to elucidate the mechanism of ED. Knowledge generated from this investigation can be used to expand applications of silver ED where strict control over the nanoscale morphology of the deposited metal is required to obtain specific chemical and physical properties

Investigations of Poly[(Styrene-Co-P-Methylstyrene)-Risobutylene- R-(Styrene-Co-P-Methylstyrene)] and Poly[(Acrylic Acid)-5-Styrene-Jb-Is0butylene-5-Styrene-Jb-(Acrylic Acid)]

The pMe study was conducted to understand the morphological and physical property changes that occur as the ratio of pMe to styrene is increased, effectively increasing the aliphatic units. By the introduction of pMe, the interface region becomes more blended/compatible as the pMe migrates to the interface. These pMe groups are theorized in effect to create multiple ‘anchors’ to distribute the loads experienced at the interface more effectively creating a synergistic effect on the final properties of the copolymers. The primary goals of the pentablock study were the characterization of unique membranes as related to the morphologies and physical properties of poly[(/-butyl acrylate)-Z\u3e-styrene-Z\u3e-isobutylene-b-styrene-b-(/-butyl acrylate)] and poly[(acrylic acid)- 6 -styrene-6 -isobutylene-Z\u3e-styrene-b-(acrylic acid)]. Specifically, the reaction to convert /-butyl acrylate to acrylic acid group as well as the anhydride ring formation and stability as it relates to morphology was explored. The overall morphologies of these pentablocks demonstrate more restrictions due to the architecture of the chain, and these three articulated phase morphologies create an opportunity for use in diffusion and charge transport in these polymers. Investigations in morphologies, physical properties, nanoindenation, permeation, diffusion, conductivity, and dielectric relaxation spectroscopy were conducted as a function of increasing acrylic acid in the pentablocks

A Study of a High Delinquency Area

This is a report of an ecological study of delinquency in a Chicago neighborhood having the fifth highest rate of delinquency compared with the 75 other neighborhood communities in the city. Ecology, broadly defined, is the study of the interrelationships between organism and the immediate environment in which it lives. In sociology, some ecological studies have been concerned with total urban areas. Others have investigated smaller areas such as neighborhoods or census tracts. The unit areas are compared with one another in terms of certain characteristics considered to be the independent variables such as housing, income, and mobility and certain conditions considered to be dependent variables. The prevalence of mental illness or juvenile delinquency are examples of the latter