(Georgia Institute of Technology, 2022-04-05)
Meredith, J. Carson
This talk will review several recent advances in utilizing cellulose nanocrystals (CNCs) in commodity materials applications. The talk will focus on developments relevant to the coatings industry, particularly waterborne coatings utilized in latex paints as well as those useful as barrier coatings for packaging materials. Waterborne acrylic latexes are found in a large variety of commercial coating and paint products, but most of these products continue to contain volatile organic solvents (VOCs). I will present recent work that demonstrates who CNCs can be used as additives to waterborne acrylic formulations to displace the use of VOCs. Notably, because CNCs enable the development of hardness in otherwise soft acrylics, the VOC is no longer needed to enable film formation during the early drying stage. We have investigated two modes of addition of CNC: addition direct to the aqueous phase after the latex is produced and addition to the monomer phase prior to polymerization. In the latter case, the latex is then produced after CNC is dispersed in monomer droplets, by miniemulsion polymerization. This presentation will also feature research on the utilization of CNC dispersions as coatings on conventional polymer films such as PET and cellulose acetate, in order to impart high oxygen barrier properties to these films.
(Georgia Institute of Technology, 2008-02-12)
Meredith, J. Carson
In this talk Professor Meredith reviewed recent advances in the high-throughput screening of polymers for advanced materials. Two applications were reviewed: proton exchange membranes (PEM) and biomaterials for cell adhesion and growth. After decades of research the essential requirements of successful PEMs are understood reasonably well. But still, even with design information available, there are millions of potential candidate materials: more than can be reasonably evaluated experimentally. A new approach for searching this space of materials more efficiently would lead to PEMs with significantly better performance-to-price characteristics. This talk reviewed a combinatorial screening system that integrates synthesis of sample libraries based on composition gradients, high-throughput screening of conductivity, mechanical properties, and transport properties. A significant challenge encountered in high-throughput research and development of organic and polymeric materials is the reproducible preparation of combinatorial libraries with programmed variations in composition. A number of examples of discrete and gradient library preparation techniques have been presented in the literature, which were reviewed in this talk.
The application of these novel techniques to polymeric biomaterials was also covered. The HTS protocol has been utilized to discover microphase-separated patterns that enhance cell attachment and proliferation for osteoblasts (bone). Informatics processing and models that enable optimization of large materials data sets was also discussed in reference to biomaterials screening.