Random copolymer gels of N-isopropylacrylamide (NIPAM) and N-ethylacrylamide (NEAM) were synthesized using a 1 : 1 monomer molar ratio in different methanol–water (xm 1⁄4 0, 0.06, 0.13, 0.21, 0.31 0.43, 0.57, 0.76, where xm 1⁄4 mole fraction of methanol) mixtures. The samples were characterized using different techniques like Fourier transform infrared spectroscopy (FTIR), scanning electron mic...

A range of chemistries were explored for the efficient covalent conjugation of DNA to poly(N-isopropylacrylamide) (poly(NIPAM)) in organic solvents. Amide coupling and thiol-ene Michael addition were found to be ineffective for the synthesis of the desired products. However, the inverse electron-demand Diels-Alder (DAinv) reaction between tetrazine (Tz) and norbornene (Nb) was found to give DNA...

The LCST-transitions of linear, well-defined polymers of N-isopropylacrylamide (NIPAM) and N-vinylcaprolactam (VCL), including a homopolymer mixture, diblock and statistical copolymers, in water are explored and compared by applying turbidity and FTIR measurements in combination with two-dimensional correlation spectroscopy (2Dcos). Only one transition is observed in all polymer systems, sugges...

Experimental Section Materials. N-Isopropylacrylamide (NIPAM, 97%, Tokyo Kasei Kagyo Co.) was purified by recrystallization from a mixture of benzene and n-hexane (1/3, v/v). Styrene (St, 99.5%, Beijing Chemical Factory) was successively washed with aqueous NaOH (5.0 wt %) and water, then distilled over CaH 2 at reduced pressure. 4-Chloro-7-nitrobenzofurazan (NBD-Cl, 99%), 2,3,3-trimethylindole...

Nanohybrids of graphene with water soluble polymer were synthesized using 'grafting from' method. GO, prepared by modified Hummers' method, was first reacted with sodium azide. Alkyne-terminated RAFT-CTA was synthesized by reaction of propargyl alcohol and S-1-dodecyl-S'-(α,α'-dimethyl-α"-acetic acid) trithiocarbonate. RAFT-CTA was grafted onto the GO sheets by facile click-reaction and subsequ...

The application of intelligent materials in drilling fluids has greatly reduced the investment human resources and effectively made up for shortcomings traditional fluids, such as insufficient directivity, poor adaptive ability difficult monitoring. Therefore, research is a valuable direction future oil gas industry. In this study, temperature-sensitive modified bentonite NIPAM-B developed by P...

We developed a robust nanosecond photonic crystal switching material by using poly(N-isopropylacrylamide) (PNIPAM) nanogel colloidal particles that self-assemble into crystalline colloidal arrays (CCAs). The CCA was polymerized into a loose-knit hydrogel which permits the individual embedded nanogel PNIPAM particles to coherently and synchronously undergo their thermally induced volume phase tr...

Near-infrared surface plasmon resonance imaging (SPRI) microscopy is used to detect and characterize the adsorption of single polymeric and protein nanoparticles (PPNPs) onto chemically modified gold thin films in real time. The single-nanoparticle SPRI responses, Δ%RNP, from several hundred adsorbed nanoparticles are collected in a single SPRI adsorption measurement. Analysis of Δ%RNP frequenc...

Microgels are important materials for both basic science and engineering and have wide applications from the study of phase transitions to the delivery of drugs. These micron and sub-micron particles, made of hydrogel materials, respond to solvent conditions. The most common microgels are environmentally sensitive, responding to temperature and pH. Our material of interest, poly (N-isopropylacr...