In this paper the improvements of the thermal stability of cured epoxy resins in air as well as in various critical media like water, solvents, aerospace and automotive fluids were investigated. Being modified with different addition levels of polysiloxane-epoxy block copolymers, the toughness was increased significantly without sacrificing the transparency of the cured resins. The embrittlement upon thermo-oxidative ageing of the epoxy resin could be reduced significantly. Losses in strength and elongation caused by thermo-oxidative degradation of the polymer were minimized. The hygrothermal stability was increased significantly as well. It was found that the coefficient of thermal expansion (CTE) at temperatures above the glass transition temperature increased tremendously upon heat ageing of the unmodified control, but not for a modified resin system. This enables the epoxy resin formulator to create systems for various electronic applications with a much better dimensional stability and an increased service life under harsh conditions.
Biosensors using artificial recognition elements have generated intensive interest from scientists and medical professionals in recent years.Their high stability and sensitivity make them easier and less costly to use, store, and manufacture than sensors based on biological recognition elements.Surfaceimprinted sensors using the organic self-assembled monolayers (SAMs) of functionalized oligomers on gold surfaces have the advantages of high contact areas, fast response, easy construction, as well as integration of the recognition element with the transducer, all of which can lead to high sensitivity.The possibility of using SAM molecules with different end groups offers the flexibility of changing the affinity of the sensor to the target biomolecules while modification of the gold surface roughness enables imprinting bio-macromolecules much larger than the length of the SAM molecules.Co-dissolution of the bio-macromolecules and the organic molecules in a blend of aqueous/organic solvents ensures the formation of SAMs and at the same time maintains the viability and configuration of the biomacromolecules.Hence the synergy established between the substrate topography, the surface chemistry, the imprinted SAM, and the molecular structure of the analyte is the essential element for the successful construction of the biosensor.This review article focuses on the recent achievements in the development of the surface-imprinted biosensors for proteins, cancer markers and viruses, from multiple groups working in this area.
For over two decades we have systematically explored structure-composition-property relationships of amorphous calcium phosphate (ACP)-based polymeric dental composites. The appeal of these bioactive materials stems from their intrinsic ability to prevent demineralization and/or restore defective tooth structures via sustained release of remineralizing calcium and phosphate ions. Due to the compositional similarity of the ACP to biological tooth mineral, ACP-based composites should exhibit excellent biocompatibility. Research described in this article has already yielded remineralizing sealants and orthodontic adhesives as well as a prototype root canal sealer. Our work has also contributed to a better understanding on how polymer matrix structure and filler/matrix interactions affect the critical properties of these polymeric composites and their overall performance. The addition of antimicrobial compounds to the formulation of ACP composites could increase their medical and dental regenerative treatment applications, thereby benefiting an even greater number of patients.
