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Inert Polymer (inert + polymer)
Selected AbstractsPreparation of Tip-Protected Poly(oxyphenylene) Coated Carbon-Fiber UltramicroelectrodesELECTROANALYSIS, Issue 23 2006El-Deen Abstract A high-yield, reliable, and reproducible method has been successfully developed to fabricate poly(oxyphenylene)-coated carbon fiber ultramicroelectrodes (POCF UMEs) with tip radii r<2,,m. During the insulation process, the tip of the electrochemically etched electrode is protected by inserting it into an inert polymer while the remainder of the electrode is insulated by electrochemical deposition of a 1,3,,m thick poly(oxyphenylene) film. Optimum conditions for poly(oxyphenylene) deposition are developed and the resulting carbon fiber UMEs showed good cyclic voltammetric behavior even after storage for more than one year. These UMEs were tested for use as amperometric scanning electrochemical microscopy (SECM) tips and successfully imaged Au/Kel-F and Al/SiCp metal matrix composites. [source] A practical interface for microfluidics and nanoelectrospray mass spectrometryELECTROPHORESIS, Issue 9 2008Sergio L. S. Freire Abstract We report a new method for fabricating nanospray ionization tips for MS, formed from glass substrates and the inert polymer, parylene-C. Using a single photolithography step, the emitters are formed contiguously with microchannels, such that no dead volumes are observed. In addition, because the devices are very thin (,0.3,mm) and the tips are formed at rectangular corners, the Taylor cone volumes are small, which makes the method attractive for future integration with microfluidic separations. Device performance was demonstrated by evaluating diverse analytes, ranging from synthetic polymers, to peptides, to nucleic acids. For all analytes, performance was similar to that of conventional emitters (pulled-glass capillaries and the Agilent HPLC ChipÔ) with the advantage of rapid, batch fabrication of identical devices. [source] Effect of substrate size on immunoinhibition of amylase activity,JOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 2 2001Ilka Warshawsky Abstract Immunoinhibition assays are hypothesized to work by antibodies blocking substrate access to enzyme active sites. To test this hypothesis, the inhibition of amylase isoenzymes by monoclonal and polyclonal antisera was assessed using substrates of varying sizes: chromogenic sustrates 3, 5, or 7 glucose units in length, novel synthetic macromolecular substrates, and starch. The synthetic macromolecular substrates consisted of small oligosaccharide substrates linked to an inert polymer that conferred a large size to substrate molecules as determined by gel filtration chromatography. When substrate size increased, amylase activity could be inhibited equivalently by antibody concentrations that are 10‐fold lower. Progressively less polyclonal serum was required to inhibit amylase activity as substrate length increased from 3 to 5 to 7 glucose units and as size was increased by linkage to a polymer. Different effects of substrate size were observed with two monoclonal antibodies. One monoclonal antibody blocked amylase activity independent of substrate size, while another monoclonal antibody had little inhibitory effect except using starch as substrate. We conclude that use of larger substrates can expand the repertoire of inhibitory epitopes on enzymes and convert a noninhibitory antibody into an inhibitory one. J. Clin. Lab. Anal. 15:64–70, 2001. [source] EFFECT OF POLYGODIAL ON MECHANICAL, OPTICAL AND BARRIER PROPERTIES OF CHITOSAN FILMSJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 2 2010L. MORENO-OSORIO ABSTRACT The mechanical, optical and barrier properties of chitosan films containing polygodial (0.0, 2.7, 13.9, 25.0 mg/g of chitosan) were studied. Water vapor permeability (WVP), tensile strength, percentage elongation at break, CIELab color parameters, hue angle and chroma of films were determined. Fourier transform infrared (FTIR) was also performed to determine functional group interaction between the matrix and polygodial added. The use of polygodial resulted in stronger films without losing their extensibility and with low WVP. Films became darker with yellow-green coloration with increasing polygodial concentration. Polygodial added to chitosan films did not have any interaction with the amino groups of chitosan as measured by FTIR. Polygodial as a natural dialdehyde can effectively be applied to enhance some physical properties of edible films prepared with chitosan. PRACTICAL APPLICATIONS There has been an increased interest in the study of edible,biodegradable packaging films during the last decade, offering an alternative and partial solution to the problem of accumulation of solid waste composed of synthetic inert polymers, and chitosan films has been studied with this purpose. Furthermore, replacing synthetic additives by natural compounds such us polygodial can be a suitable manner to improve some physical properties of those chitosan films. [source] "Plastic Trash goes Biohybrid",Rapid and Selective Functionalization of Inert Plastic Surfaces with Biomolecules,MACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 2 2010Stefan M. Schiller Abstract The covalent functionalization of "inert" polymers such as polypropylene with biomolecules for biocompatible or biosensor surfaces is challenging. Here we present a powerful approach to covalently modify "inert" macromolecular surfaces with biomacromolecules reusing old plastic material. A special emphasis was placed on easily accessible materials and a process which is easy, fast, efficient, cheap, and reliable. "Plastic trash" (lids from Eppendorf® pipet tip containers) was used as a polymer substrate to demonstrate the use/reuse of commercial packing material to covalently modify this material with a thin reactive plasma polymerized maleic anhydride nanolayer network, which can be subsequently modified with biomolecules for various applications, e.g., in tissue engineering and as biochips. [source] | ||||||||||