Richard E. Riman

Hydrothermal synthesis, micro-encapsulation, sol-gel fluoride glass synthesis, pyrolysis, carbothermally-derived non-oxides, powder characterization, granulation, colloid chemisty, surface chemistry, thermodynamic and kinetic process modeling.

My ultimate research objective is to prioritize the powder and particle packing characteristics in terms of their relative importance to sintering behavior and to properties of ceramic materials. This goal can be realized by collaborative efforts between my research group conducting powder processing research and other faculty whose research centers more on sintering and property evaluation of ceramic materials. Before collaborative efforts can begin, however,research efforts first must focus on attaining control of individual powder and green compact characteristics. Independent control of each characteristic is desired. This entails, for example, the ability to prepare powders of various particle size while maintaining size distribution, degree of agglomeration, purity, etc., constant for all samples. In addition, it is of equal importance to understand the limitations of the characterization tools that enable us to determine when the above systems have been prepared. Consequently, my research group focuses on both materials synthesis and characterization.

(a) MATERIALS SYNTHESIS

Particle Coating/Calcination: The general approach is (1) to form the multilayer structure using precipitation from homogeneous solution, colloidal, mechanofusion or hybridization methods and (2) to control multicomponent oxide formation and the physical characteristics of the composite particles using a protective calcination method.
Hydrothermal Synthesis: Research is being focused on understanding the mechanisms that facilitate the formation of an ideal powder.
Polymer Pyrolysis: This program focuses on how the nature of a polymeric precursor influences the physical and chemical characteristics of the pyrolysis product.
Sol-Gel Synthesis: A novel sol-gel approach is being used to prepare nonoxide glasses for optical applications.

(b) POWDER CHARACTERIZATION

Particle Sizing: Research is underway to compare different particle sizing technologies as these pertain to ceramic powder characterization. The aim of this research is to develop good in-house methods for referencing and calibrating the various instruments.
Surface Chemistry: Research is underway to develop methods for characterizing the surface of ceramic powders in a quantitative yet convenient manner. This research aims to develop characterization methodologies and establish a ceramic powder database by examining the colloid chemistry and the preparative aspects of the process.