A novel method of producing a poly(ethylene glycol) (PEG)-based gradient matrix that varies gradually in thickness from 0 to 500 A over a distance of 5-20 mm is presented. The gradient matrix is graft copolymerized from a mixture of PEG methacrylates onto organic thin films providing free radical polymerization sites initiated by UV irradiation at 254 nm. The films used as grafting platforms co...

The tridentate ligand 2,6-bis(3,5-diphenylpyrazol-1-ylmethyl)pyridine, abbreviated as 2,6-[(3,5-ph₂pz-CH₂)₂-py], a new pyridine-pyrazole derivative, was prepared from 2,6-bis(bromomethyl)pyridine and 3,5-diphenylpyrazole. The ligand was characterized by means of elemental analyses, ATR-IR, ¹H- and ¹³C-NMR spectroscopy and single crystal X-ray crystallography. Using this ligand, a new mononuclea...

Aqueous coordination polymerization of ethylene by different neutral nickel(II) complexes [(X∧O)NiR(L)] (X ) P: type 1; X ) N: type 2) was investigated. With catalyst precursors of type 1, productivities and molecular weights were reduced by comparison to conventional polymerization in organic solvents. This effect results to a large extent from a lowering of the chain growth rate due to a low ...

a series of ethylene-propylene-2-ethylidenebicyclo [2.2.1] hept.5-ene terpolymers (epdm) have been prepared using a vocl3/al2et3cl3 catalyst under various al/v ratios and diene concentrations via solution polymerization and characterized by ftir, mooney viscosity (ml1+4,125oc), and thermal gravimetery analyzing. the polymerization yield was seen to increase with augmentation of the al/v ratio a...

Free radical photopolymerization dominates most of the industrial applications of photocuring. The most popular are protective coatings, dental fillings, adhesives, inks, lithography (printing plates), stereolithography but also advanced hightechnology purposes (micro and optoelectronics, holographic data storage, etc.) [1]. Currently, radical photopolymerization is also applied to prepare new ...

Two types of photoinitiator are considered: (1) transition metal complexes (mainly carbonyls), (2) chelates of transition metals. In systems of type (1) the metal is in a low oxidation state and an organic halide is generally, but not always, present; on thc other hand, in (2) the metal is initially in a high oxidation state. Comparison between photoand thermal-initiation is made for each type....

This work describes the fabrication of poly(4-styrenesulfonic acid)-doped polyaniline/graphene (PSS-doped PANI/graphene) nanocomposites and their use as sensing elements for hydrogen sulfide (H2S) detection. PSS with a weight-average molecular weight (Mw) of 1.96 × 10(6) was synthesized using low-temperature free-radical polymerization. The PSS was used as both a doping agent and a binding agen...

Biocompatible magnetic nanoparticles hold great therapeutic potential, but conventional particles can be toxic. Here, we report the synthesis and alternating magnetic field dependent actuation of a remotely controllable, multifunctional nano-scale system and its marked biocompatibility with mammalian cells. Monodisperse, magnetic nanospheres based on thermo-sensitive polymer network poly(ethyle...

A series of nanospheres composed of temperature-sensitive poly(N-isopropylacrylamide), poly(ethylene glycol) 400 dimethacrylate, and poly(ethylene glycol) 1000 methacrylate was prepared by a thermally-initiated free radical dispersion polymerization method. Insulin was loaded into the nanoparticles by equilibrium partitioning. The loading capacity of insulin into the nanoparticles was 2.1% (2.1...