Title

Design, Synthesis, and Film Formation of Multi-Component Colloidal Dispersions

Date of Award

2005

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Polymers and High Performance Materials

First Advisor

Marek W. Urban

Advisor Department

Polymers and High Performance Materials

Abstract

A number of colloidal dispersions were synthesized to advance knowledge and gain understanding regarding interactions between individual components and for elucidation of complex processes governing their film formation. The studies show that for styrene/ethylhexyl acrylate/methacrylic acid (Sty/EHA/MAA) colloidal dispersions, the presence of low-level crosslinking agents and ionic species significantly affects film formation. Sty/EHA/MAA dispersions containing adipic dihydrazide/diacetone acrylamide (ADDH/DAAM) crosslinking agents coalesce at low rates with limited stratification of sodium dodecyl sulfate (SDS) near the film-air (F-A) interface. Elevated temperatures are required for complete particle coalescence with subsequent migration of SDS to the F-A interface, but in the absence of crosslinking agents, ambient conditions are capable of facilitating this process. Likewise, upon film formation of methyl methacrylate/n-butyl acrylate (MMA/nBA) colloidal particles, SDS migrates to the F-A interface, but in the presence of acrylic acid (AA), interactions between SDS and COOH groups demobilize SDS, rendering a latex film with SDS distributed in the bulk. However, the presence of propylene glycol (PG) in MMA/nBA/AA colloidal dispersions displaces interactions between SDS and AA, thus mobilizing SDS in such a way that PG/SDS islands are formed near the F-A interface. Film formation processes resulting from coalescence of n-butyl acrylate/acrylonitrile/methacrylic acid (nBA/AN/MAA) colloidal particles stabilized by sodium dodecyl diphenyl oxide disulfonate (DDOD) are affected by chemical and physical stimuli such as the presence of benzophenone (BPO), Ca(OH) 2 , substrate surface tension, and film thickness. Subsequently, the distribution of BPO in nBA/AN/MAA colloidal films is directly related to interfacial tensions present between the aqueous phase and the substrate where substrates with higher surface tensions resulted in increased surface concentration levels of BPO. (Abstract shortened by UMI.)