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Functionalized Materials (functionalized + material)

Distribution by Scientific Domains
Polymers and Materials Science60%

Selected Abstracts

Preparation and characterization of pore wall-functionalized three-dimensionally ordered macroporous syndiotactic polystyrene

POLYMER ENGINEERING & SCIENCE, Issue 2 2009
Xu Zhang
A versatile method for the modification of three-dimensionally ordered macroporous (3DOM) highly syndiotactic polystyrene via chloromethylation at the pore walls has been demonstrated. This was followed by reaction with dimethylamine to establish a versatile approach to functionalization of such macroporous polymers. High syndiotacticity of 3DOM sPS is necessary for maintenance of the morphology of the original ordered pore structure after chloromethylation. The relative content of chloromethyl groups was shown to be 1.89 mmol/g3DOM sPS by TG-titration. The functionalized 3DOM sPS was characterized by SEM, FT-IR, and DSC to demonstrate that chloromethylation had occurred at the pore walls and that the dimethylamino moiety had replaced the chlorine atom of the chloromethyl group. DSC examination of the modified polymer indicated that the crystallinity of 3DOM sPS is little affected by functionalization. Thus the excellent properties of sPS are retained by the functionalized material. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers [source]

Novel bioactive scaffolds with fibronectin recognition nanosites based on molecular imprinting technology

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2010
Elisabetta Rosellini
Abstract Biomimetic materials for application in the field of tissue engineering are usually obtained through covalent bonding between the polymer backbone and the bioactive molecules. A totally new approach, proposed for the first time by our research group, for the creation of advanced synthetic support structures for cell adhesion and proliferation is represented by molecular imprinting (MI) technology. In this article, we describe the synthesis and characterization of molecularly imprinted polymers with recognition properties toward a fibronectin peptide sequence and their application as functionalization structures. Polymers, in the form of densely fused microgel particles, were obtained by precipitation polymerization. The imprinted particles showed good performance in terms of recognition capacity and quantitative rebinding; moreover, the epitope effect was observed, with the particles able to recognize and rebind not only the specific peptide sequence but also a larger fibronectin fragment. The cytotoxicity tests showed normal vitality in C2C12 myoblasts cultured in a medium that was put in contact with the imprinted particles. Therefore, imprinted particles were used to functionalize synthetic polymeric films by deposition on their surface. The deposition of the imprinted particles did not alter their specific recognition and rebinding behavior. The most remarkable result was obtained by the biological characterization: in fact, the functionalized materials appeared able to promote cell adhesion and proliferation. These results are very promising and suggest that MI can be used as an innovative functionalization technique to prepare bioactive scaffolds with an effective capacity for improving tissue regeneration. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source]

Protein immobilization on liposomes and lipid-coated nanoparticles by protein trans -splicing,

JOURNAL OF PEPTIDE SCIENCE, Issue 10 2010
Nam Ky Chu
Abstract A plethora of methods exist to link proteins to surfaces in order to generate functionalized materials. However, general tools that lead to functional immobilization of recombinantly expressed proteins on membranes such as liposomes or lipid-coated nanoparticles are rare. Here we present an approach that takes advantage of a double-palmitoylated peptide that mediates stable membrane anchoring in combination with protein trans -splicing for efficient immobilization of recombinant proteins fused to split intein segments. Two different DnaE split inteins from Synechocystis and Nostoc punctiforme are tested and compared to immobilization via direct native chemical ligation using a protein thioester. Protein trans -splicing proceeds at low protein concentrations and leads to functionalized vesicles and membrane-coated silica nanoparticles. Copyright © 2010 European Peptide Society and John Wiley & Sons, Ltd. [source]

A Scalable Route to Highly Functionalized Multi-Walled Carbon Nanotubes on a Large Scale

MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 8 2008
Xianhong Chen
Abstract A scalable and solvent-free chemical process to obtain highly functionalized and dispersible multi-walled carbon nanotubes is reported. Highly functionalized multi-walled carbon nanotubes have been prepared using in situ generated aryl diazonium salts in the presence of ammonium persulfate and 2,2,-azoisobutyronitrile by solvent-free techniques. In the Raman spectra of the resulting materials, characteristic peaks, the D- and G-bands, are shifted by about 10 cm,1 to lower frequencies. At the same time, the relative intensity ratios between the D- and G-bands increase in comparison to that in the spectrum of the purified product. Fourier-transform infrared spectroscopy reveals the presence of the functional groups on the surface. Transmission electron microscopy images directly confirm the significant build-up of sidewall organic moieties on the treated materials. The weight loss of various functional moieties determined by thermogravimetry,differential scanning calorimetry analysis is about 18,33%. The dispersibility of the functionalized materials in solvents, such as chloroform, tetrahydrofuran, and water, is obviously improved. [source]

Physical adsorption vs. chemical binding of undecylenic acid on porous silicon surface: a comparative study of differently functionalized materials

PHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 7 2009
E. Pastor
Abstract To imply miscibility to porous silicon (PSi) used for biomedical purposes a number of functionalization methods are employed. In order to distinguish between a non-specific surfactant-like interaction (physical sorption) and chemical binding of unsaturated chemicals (undecylenic acid, UD) to H-terminated PSi surface we studied the two differently treated materials. Differential scanning calorimetry (DSC) and thermogravimetry (TGA), BET and FTIR measurements were performed with the PSi powder samples (n+ doped). Changes in surface area, weight loss, calorific effect and chemical composition that accompanied the thermal treatment have shown that the physisorbed UD molecules undergo a chemical process (binding) with the Si-Hx surface groups at about 150 °C in both, N2 inert atmosphere and in a synthetic air, oxidative atmosphere. Controlled conversion of physically sorbed molecules to the chemically attached ones is discussed with respect to methods of surface modification of PSi materials for increasing their biocompatibility. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]