Surface zwitterionicalization of poly(vinylidene fluoride) membranes from the entrapped reactive core-shell silica nanoparticles.

We demonstrate the preparation and properties of poly(vinylidene fluoride) (PVDF) filtration membranes modified via surface zwitterionicalization mediated by reactive core-shell silica nanoparticles (SiO2 NPs). The organic/inorganic hybrid SiO2 NPs grafted with poly(methyl meth acrylate)-block-poly(2-dimethylaminoethyl methacrylate) copolymer (PMMA-b-PDMAEMA) shell were prepared by surface-initiated reversible addition fragmentation chain transfer (SI-RAFT) polymerization and then used as a membrane-making additive of PVDF membranes. The PDMAEMA exposed on membrane surface and pore walls were quaternized into zwitterionic poly(sulfobetaine methacrylate) (PSBMA) using 1,3-propane sultone (1,3-PS) as the quaternization agent.

Versatile antifouling polyethersulfone filtration membranes modified via surface grafting of zwitterionic polymers from a reactive amphiphilic copolymer additive.

Here we describe the development of versatile antifouling polyethersulfone (PES) filtration membranes modified via surface grafting of zwitterionic polymers from a reactive amphiphilic copolymer additive. Amphiphilic polyethersulfone-block-poly(2-hydroxyethyl methacrylate) (PES-b-PHEMA) was beforehand designed and used as the blending additive of PES membranes prepared by phase inversion technique. The surface enriched PHEMA blocks on membrane surface acted as an anchor to immobilize the initiating site.

[Evaluation on intervening efficacy of health education on accidental suffocation and drowning of children aged 0 - 4 in countryside].

Objective: The main causes of death in children aged 0 - 4 were accidental suffocation and drowning which had a significant relation with parents' lack of prevention knowledge and effective measures. By comparing parents' acknowledge and behavior in preventing accidental suffocation and drowning and the mortality rate of accidental suffocation and drowning after intervening with those before the intervening, evaluation was made on intervening efficacy of health education.

Methods: Six counties in north Jiangsu were involved in the survey.