Novel nanostructured pHEMA–TiO2 hybrid materials with efficient light-induced charge separation

Abstract

We report on a new approach to the fabrication of an electronic material: organic-inorganic pHEMA-oxo-TiO(2) hybrid with efficient light-induced separation of charges. Particular attention is paid to the material nanoscale morphology. The size-selected 5.0 nm titanium oxo-alkoxy nanoparticles are prepared in a sol-gel reactor with rapid (turbulent) fluid micromixing and the ligand exchange results in a stable nanoparticulate precursor in HEMA solution, in which polymerization can be induced thermally or by photons. The obtained hybrid materials demonstrate the highest quantum yield of photoinduced charge separation of 50% and can store photoinduced electrons at a number density above 10% Ti atoms.

A novel route for the synthesis of poly(2‐hydroxyethyl methacrylate) grafted TiO2 nanoparticles via surface thiol‐lactam initiated radical polymerization

“…High density of hydroxyl groups within PHEMA hydrogels provides a hydrophilic surface that exhibits low interfacial free energy with most body fluids, resulting in minimal adhesion of proteins and cells to their surfaces. The combination of excellent biocompatible properties of PHEMA and the beneficial characteristics of TiO 2 produced a promising composite biomaterial for tissue engineering scaffolds and biomedical implants and devices 18–22…”

A New Route for High-Purity Organic Materials: High-Pressure-Ramp-Induced Ultrafast Polymerization of 2-(Hydroxyethyl)Methacrylate

“…In addition to its high efficiency, the major advantage of HPR polymerization is the production of long polymer chains in a very short reaction time (few minutes), which is much shorter than that (several hours to days) required for polymerization at static high pressure 4 5 6 10 11 12 . Due to the large field of application of poly-HEMA (pHEMA) as a highly biocompatible material 19 20 , the HPR process leading to the most pure pHEMA without the use of potentially toxic catalysts, is extremely appealing for medical applications or elaboration of photosensitive organic-inorganic hybrid materials 21 22 23 .…”

Effect of Light Intensity on the Free-Radical Photopolymerization Kinetics of 2-Hydroxyethyl Methacrylate: Experiments and Simulations

“…The poly 2-hydoxyethyl methacrylate (pHEMA) is a biocompatible material with many applications in biomedicine for fabrication of artificial coronae, contact lenses, drug delivery systems or tissue engineering 3,[21][22][23] . Combined with an inorganic component, it is also used to synthesize photoactive hybrids with applications in optoelectronics or sensors technology [24][25][26][27][28] . The FRP of the monomer 2-hydoxyethyl methacrylate (HEMA) with different types of crosslinkers and photoinitiators has been therefore studied for a long time and remains today a topical issue [29][30][31] .…”