RESUMO
As a function of the ability of the solvent to behave as acceptor of halogen bonding, the NLO-phores under study give rise to microbeta(lambda) values ranging from +192 x 10(-48) esu to -465 x 10(-48) esu.
RESUMO
Primary and secondary aliphatic alcohols are smoothly oxidised by air to the corresponding carbonyl derivatives with high selectivity using 1% Au on silica.
RESUMO
Chemically crosslinked hyaluronic acid hydrogels are synthesized with a homogeneous crosslinking process using divinyl sulfone (DVS) as crosslinking agent. Testing different conditions, in terms of both DVS content and curing time, we aim to keep control over the crosslinking process in order to prepare biocompatible hydrogels with mechanical properties closely approximating those of extracellular matrix (ECM) of natural stem cells niches (0.1÷50kPa). The hydrogels properties are evaluated through a reliable methodology based on three independent techniques: dynamic rheological analysis, used as benchmark method; swelling experiments following the Flory-Rehner theory and atomic force microscope (AFM) nanoindentation experiments. Our results demonstrate that controlling crosslinking parameters it is possible to design hydrogels with desired elastic moduli values. HA hydrogels can be ideal coating materials to be implemented in regenerative medicine and particularly in the engineering of ECM niches in vitro.
Assuntos
Materiais Biomiméticos/química , Ácido Hialurônico/química , Hidrogéis/química , Teste de Materiais , Fenômenos Mecânicos , Medicina Regenerativa/métodos , Microscopia de Força Atômica , Reologia , Sulfonas/químicaRESUMO
The importance of the choice of a suitable substrate as supporting material for photoactive TiO(2), either in the form of powders or thin films or in photoactive paints, is frequently disregarded. In this paper four different supports (stainless steel, sand-blasted stainless steel, Teflon and glass) are object of investigation. The final aim is to verify the presence of interactions between the photocatalyst (AEROXIDE(®) TiO(2) P25 by Evonik Degussa Corporation) and the support, directly involved in the photocatalytic activity in the NO(x) abatement. The characterization results have been correlated with the photoactivity of the different samples. In particular, a coating of about 6-9 µm seems to allow a photocatalytic result free from any positive or negative interference with the supporting material, therefore giving reliable results about the photoactivity of the TiO(2) under investigation.