Patterned poly(N-isopropylacrylamide) (PNIPAAm) brushes were fabricated on oxidized silicon wafers by surface-initiated atom transfer radical polymerization of N-isopropylacrylamide from a micropatterned initiator. The patterned surface initiator was prepared by microcontact-printing octadecyltrichlorosilane and backfilling with 3-(aminopropyl)triethoxysilane followed by amidization with 2-brom...

Polyaniline (PANI) nanocomposite has been successfully prepared in aqueousmedia by the chemical polymerization of aniline with ammonium peroxydisulphateas an initiator in the presence of a steric stabilizer such as sodium dodecylbenzenesulfonate(DBSNa), Poly(vinyl pyrrolidone) (PVP), poly(vinyl alcohol)(PVA), poly(ethylene glycol) (PEG) and hydroxypropylcellulose (HPC). Thechemical structure, m...

The Ce/ Ce redox system was studied to initiate the grafting of idustrial cellulose pulp with vinyl acetate monomer. The parameters of the copolymerization reaction (reaction time, temperature, monomer and initiator contentration, freeness, chemical composition of the cellulose) were investigated and their effects are discussed.

Chirality arising from isotope substitution, especially with atoms heavier than the hydrogen isotopes, is usually not considered a source of chirality in a chemical reaction. An N2 ,N2 ,N3 ,N3 -tetramethyl-2,3-butanediamine containing nitrogen (14 N/15 N) isotope chirality was synthesized and it was revealed that this isotopically chiral diamine compound acts as a chiral initiator for asymmetri...

Abstract Complexes from catalysts and initiator can be used to insert a specific number of additional chemical functional groups in (co)polymers prepared by ring-opening polymerization (ROP) lactones. We report on the synthesis cooligomers sec -butyl-morpholine-2,5-dione (SBMD) para -dioxanone (PDX) ROP with varied feed ratios bulk using catalyst complex SnOct 2 /2-hydroxyethyl sulfide. M n (de...

We report a facile and versatile scanning probe based approach-dip-pen nanodisplacement lithography (DNL)--for manipulating nanostructures of polymer brushes. Nanostructured polymer brushes with sizes as small as 25 nm are made by DNL patterning of the initiator molecules and subsequent surface-initiated polymerization. Nanoconfinement effects including chain collapsing and spreading are observ...

It has been demonstrated in several model systems that tumors arise in a multistage process. Carcinogenic aromatic amines are complete carcinogens, which usually produce tumors in typical target tissues without any additional treatment. The tissue specificity, however, cannot readily be explained by genotoxic effects, and the role of secondary effects is not well understood. Promotional pressur...

The nature of the active species which lead to the formation of the initiator carbene in photocatalytic metathesis reaction was investigated. The solid phase produced during irradiation was found to involve the active species while the soluble species showed no catalytic activity. The structure of the active solid was analyzed by ESCA, FT IR, NMR and chemical analysis methods and defined as a t...

Modification of natural polymers like protein by graft co-polymerization is an important method to incorporate the desired properties into the backbone. Soy protein concentrate (SPC) was grafted with ethylmethacrylate (EMA) using ascorbic acid /potassium persulphate as redox initiator system under pressure. Different reaction parameters such as reaction time, reaction pressure, solvent amount, ...