The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
In a previous study, we demonstrated the feasibility of retaining poly(N-isopropylacrylamide) (pNIPAAm) on hydroxylated surfaces by spin-coating a blend of pNIPAAm with a small amount of 3-aminopropyltriethoxysilane (APTES), an organosilane, followed by thermal annealing. In this study, we detail the conditions for retaining pNIPAAm films by APTES. Our results show that the difference in surface energy...
Several polymers are constructed through a facile one-pot approach connecting glycoluril with different aldehydes using p-toluenesulfonic acid as both catalyst and solvent in a sealed tube at high temperature. Fourier transform infrared and solid-state 13C CP/MAS NMR spectroscopy are used to elucidate the final structure of the glycoluril based porous organic polymers. The materials, with Brunauer–Emmet–Teller...
The response of collagen molecules in acid solution (0.25, 0.50 and 1.0 mg/mL) to temperature (20–50 °C) was studied by ultra-sensitive differential scanning calorimeter (US-DSC), atomic force microscopy (AFM) and fluorescence spectrophotometer. The enthalpy changes (ΔH) for collagen varied with collagen concentrations, indicating that the aggregation state of collagen molecules was correlated with...
An amphiphilic diblock copolymer of poly(acrylic acid-b-dl-lactide) (PAAc-b-PDLLA) was synthesized by ring-opening polymerization of dl-lactide initiated by hydroxyl-terminated polyacrylic acid (PAAc-OH). The critical micelle concentration (CMC) of PAAc-b-PDLLA in aqueous solution, determined by fluorescence spectroscopy using pyrene as a probe, was found about 80mgL −1 . A solution of PAAc-b-PDLLA...
Controlled/living radical polymerization of styrene has been achieved by atom transfer radical polymerization (ATRP) catalyzed by cobaltocene (PDI=1.27–1.41). The effects of the initiators, temperatures and solvents were studied. The end group of PS–Br was characterized by 1 H NMR. Block copolymerization proved that the polymer end is still living and the PMMA-b-PSt block copolymer was synthesized.
A novel hyaluronan (HA) derivative was synthesized through silylation reaction to improve the hydrophobicity of HA, to enhance its solubility in common organic solvents, and to make it more reactive for further derivatizations (e.g. esterification). While HA can not be silylated directly, its ion-paired complex with a long aliphatic chain quaternary ammonium salt (HA–CTA) was an effective starting...
Atom transfer radical suspension polymerization (suspension ATRP) of methyl methacrylate (MMA) was carried out using 1-chloro-1-phenylethane (1-PECl) as initiator, copper chloride/bipyridine (CuCl/bpy) as catalyst. The polymerization was accomplished with a mechanical agitator under the protection of nitrogen atmosphere. Apart from the dispersing agent (1% PVA), NaCl was also used in the water phase...
Melting and crystallization of two types of polyhydroxyalkanoates (PHAs), poly(3-hydroxybutyrate) homopolymer (PHB) and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) random copolymer (PHBHHx) were studied via in situ Fourier transform infrared spectroscopy (FTIR). The absorbance variances of the crystalline and the amorphous bands revealed that melting of PHB occurred at a narrow temperature range,...
Using atomic force microscopy, film stability is investigated for poly(methyl methacrylate) (PMMA)/poly(styrene-ran-acrylonitrile) (SAN) thin film blends ranging from 10nm to a few microns thick and deposited on an oxide covered silicon substrate. In addition to characterizing the surface morphology, the PMMA rich phase which wets the surface and oxide, is selectively etched to reveal the underlying...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.