Search results for " hydrogel"
showing 7 items of 277 documents
Gelled electrolyte for nanostructured lead-acid battery
2019
In recent years, the storage of energy produced by renewable sources has become a topic of great interest. Lead-acid batteries are widely used in this field, in particular those based on VRLA (Valve-Regulated-Lead Acid) technology, in which the electrolyte is immobilized inside the battery. In this paper, the use of a hydrogel as an electrolyte was considered. Hydrogel can be described as a three-dimensional network of a hydrophilic polymer that can absorb large amounts of water (or aqueous solutions) without dissolving. Pb and PbO2 nanostructured electrodes were used in the battery that used hydrogel as an electrolyte. Two different types of hydrogels were synthesised, both based on PVA th…
Periodically nanostructured hydrogels for ethanol vapors sensing
2013
Chemical sensing using optics has been under extensive research all over the world during last decades and many optical chemical sensors are nowadays finding increasing applications in industry, environmental monitoring, medicine, biomedicine and chemical analysis. These optical sensors can be based on various optical principles, such as absorbance, reflectance or transmittance, luminescence and fluorescence, covering different regions of the spectrum (UV, visible, IR, NIR). Optical chemical sensors have several advantages over conventional electricity-based sensors, in terms of selectivity, immunity to electromagnetic interference, higher sensitivity, and they are also relatively inexpensi…
Feedback and Communication in Active Hydrogel Spheres with pH Fronts: Facile Approaches to Grow Soft Hydrogel Structures
2021
Abstract Compartmentalized reaction networks regulating signal processing, communication and pattern formation are central to living systems. Towards achieving life‐like materials, we compartmentalized urea‐urease and more complex urea‐urease/ester‐esterase pH‐feedback reaction networks into hydrogel spheres and investigate how fuel‐driven pH fronts can be sent out from these spheres and regulated by internal reaction networks. Membrane characteristics are installed by covering urease spheres with responsive hydrogel shells. We then encapsulate the two networks (urea‐urease and ester‐esterase) separately into different hydrogel spheres to devise communication, pattern formation and attracti…
PHOTOCROSSLINKING OF DEXTRAN AND POLYASPARTAMIDE DERIVATIVES: A COMBINATION SUITABLE FOR COLON- SPECIFIC DRUG DELIVERY.
2007
The aim of this study was to prepare and characterize novel hydrogels with polysaccharide–polyaminoacid structure, able to undergo an enzymatic hydrolysis in the colon and potentially useful for treating inflammatory bowel diseases (IBD). Starting materials were methacrylated dextran (DEX-MA) and methacrylated α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHM). These polymers were photocrosslinked by exposure of their aqueous solutions at 313 nm without photoinitiators. Different samples, shaped as microparticles, were obtained as a function of polymer concentration and irradiation time. FT-IR analysis confirmed the occurrence of a co-crosslinking between DEX-MA and PHM in all experimental con…
New composite materials made up of nanofibers and hydrogel as biomimetic scaffolds for human pluripotent stem cell culture
2014
Dynamics of protein–solvent systems in hard confinement studied by Broadband Dielectric Spectroscopy and Neutron Scattering
2008
New polysaccharide-polyaminoacid hydrogels: a suitable strategy for colon-specific drug delivery
2007
The aim of this study was to prepare and characterize novel hydrogels with polysaccharide–polyaminoacid structure, able to undergo an enzymatic hydrolysis in the colon and potentially useful for treating inflammatory bowel diseases (IBD). Starting materials were methacrylated dextran (DEX-MA) and methacrylated α,β-poly(N-2-hydroxyethyl)-DL-aspartamide (PHM). These polymers were photocrosslinked by exposure of their aqueous solutions at 313 nm without photoinitiators. Different samples, shaped as microparticles, were obtained as a function of polymer concentration and irradiation time. FT-IR analysis confirmed the occurrence of a co-crosslinking between DEX-MA and PHM in all experimental con…