Consulting, Contract Research, and Expert Witness 

Silicones have many commercial applications (see technical areas, below).  We support external research endeavors by providing custom research and testing on silanes and silicones. In addition, Brook has acted as consultant and/or as an expert witness in a variety of technical areas. In addition, he has served on Regulatory Panels for Health Canada and made petitions, on behalf of companies, to the FDA.

Areas of Consulting Expertise  

Silicones and Siloxanes (Oils, Gums, Rubbers, Coatings)

Siloxane compounds have very special properties which lead to their usage for many industrial applications including as foaming agents, defoamers, lubricants, mold releases (low surface energy) and electrical tranformers (high thermal stability, high electrical resistivity). Our group has experience in preparing silicones and modifying their molecular weight profile. We are also active in the development of new strategies to incorporate functional organic sidechains that lead to surface activity, and enhanced biocompatibility.

Silicone Elastomers / Rubbers

Silicone elastomers are used as sealants, electrical insulants, release coatings, biomedical applicaitons and many others.  Our research examines strategies to control both the internal structure and external interfaces to change compatibility.  We are also active in the development of alternative cure chemistry (see next section).  In addition to standard potting and sealing elastomers, foamed structures can be created.

Silicone Cure Chemistry

RTV Cure

Room temperature vulcanization cure or moisture cure silicones are often used in sealing applications (e.g., bathtub caulking). The presence of water in the atmosphere and catalysts (typically tin or titanium based) in the one part system effect the cure. We are manipulating moisture cure processes to control surface and internal structuring, for example, to manipulate drug release profiles.  

Addition (Platinum) Cure

Two part systems usually rely on hydrosilylation catalyzed by platinum catalysts (hydrosilation involves the coupling of an Si-H containing compounds with an alkene RCH=CH₂). Silicones produced this way are of use as potting compounds, sealants, silicone rubbers and paper coating among other applications. They are also widely used in biomedical devices: we have examined regulatory concerns about platinum in these systems.  

New cure systems

Click chemistry (alkyne + azide) will operate in absence of any metal catalyst.  Piers-Rubinsztajn condensation is catalyzed by boron Lewis acids. These two protocols offer new, metal-free strageties to create silicone elastomers.

Surface Active Silanes

Silanes are active at interfaces.  They are used as surfactants, foam stabilizers (e.g., polyurethane foams), as defoamers (e.g., in antacid preparations) and adjuvants (superwetters) in delivery of agricultural chemicals.  Most of these compounds are based upon silicone-polyether (e.g., poly(ethylene glycol)(PEG) graft copolymers.  We are currently preparing new materials based on silicones grafted to PEG, and natural products including proteins, polysaccharides and DNA.  These amterials cna be utilized to structure silicone elastomers and to hydrophilize silicone and other surfaces.

Silane Coupling Agents

Organofunctional silanes (silane coupling agents) are used to stabilize inorganic materials in organic matrices and as adhesion promotors (e.g., fiberglass reinforced polyester, use of silica as a filler, improved silicone (or other material) adhesion to a metal surface). Different functional species are available, including bases, thiols, radically active groups, etc. We have developed new multifunctional coupling agents and used them extensively in the modification of monolithic and colloidal silica both to change the chemical nature of the surface and the electrostatic charge on the surface.