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Membrane Consisting (membrane + consisting)
Selected AbstractsPreparation and self-assembly of polyaniline nanorods and their application as electroactive actuatorsJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2010Seong Hun Kim Abstract To improve the performance of ion-exchange polymer,metal composite (IPMC) actuators, an electrical pathway material for enhancing the surface adhesion between the membrane and the metal electrodes of the IPMC was studied. As an efficient electrical pathway material, polyaniline nanorods (PANI-NRs) doped with p -toluene sulfonic acid (TSA) were synthesized with a template-free method. The factors affecting polyaniline morphology were studied with various dopant concentrations and oxidant feeding rates. Highly conductive PANI-NRs were formed when they were synthesized with ammonium persulfate at a 5.0 mL/min oxidant feeding rate and doped with 0.125M TSA. The conductivity of the PANI-NRs was 1.15 × 10,1 S/cm, and their diameters and lengths were 120,180 nm and 0.6,2 ,m, respectively. To apply the membrane as an actuator, perfluorosulfonated ionomer (Nafion)/PANI-NR blends were prepared by solution blending and casting. The actuating ability of the three-layered membrane consisting of Nafion/PANI-NR blends was then examined and compared with that of Nafion only. The actuating ability of the IPMC was improved when Nafion/PANI-NRs were used as electrical pathways. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] The new adhesion prophylaxis membrane A-part®,From in vitro testing to first in vivo resultsJOURNAL OF BIOMEDICAL MATERIALS RESEARCH, Issue 2 2009Bernd Martin Jaenigen Abstract Introduction: Formation of postoperative intra-abdominal adhesions is a severe problem in surgery. Apart from standard surgical procedures, a variety of different substances is available to prevent adhesions, but no universal method has been developed so far. A membrane consisting of polyvinyl alcohol (PVA) and carboxymethylcellulose (CMC) has been demonstrated to be antiadhesive. Here, the in vitro testing and first in vivo results in a rabbit sidewall model are reported. Materials and Methods: A-part® membrane contains a PVA/CMC mixture in a thickness of 40 ,m. The composition, dissolution, tensile strength, and elasticity were examined to characterize the membrane in vitro. Experiments in vivo were carried out using a ,rabbit sidewall model' in which a standardized peritoneal trauma was covered with a 5 × 6 cm A-part® membrane. Adhesion formation in A-part®-treated animals was compared with that in Adept® (15 mL/kg body weight) and untreated controls. Results: An 80/20 PVA/CMC mixture forms a stable, elastic, transparent membrane, which can easily be placed intraoperatively. The dissolution shows a half-life of about 2 weeks [day 15: (45.1 ± 4.9)% SD], which affords good adhesion protection during the initial critical phase of adhesion formation. In wet conditions, the membrane follows abdominal movements without tearing (tensile strength 5.0 ± 4.2 N/cm SD; elasticity 29.5%). In a rabbit sidewall model, A-part® membrane significantly reduced adhesion development by (83.1 ± 31.5)% SD compared with the control and the Adept group (p < 0.001). Conclusion: The properties of the A-part® membrane suggest that it may be useful as an antiadhesive in surgery. A-part® is effective in invivo testing as determined in a rabbit sidewall model. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2009 [source] Extraction of alcohol using emulsion liquid membrane consisting of paraffin oil as an organic phase and lecithin as a surfactantJOURNAL OF CHEMICAL TECHNOLOGY & BIOTECHNOLOGY, Issue 2 2010B.S. Chanukya Abstract BACKGROUND: This paper reports on the use of a liquid emulsion membrane involving paraffin light oil as membrane phase and lecithin as surfactant for the extraction of alcohol from anthocyanin extract and simulated pineapple wine. RESULTS: The extraction of alcohol was found to depend on the many factors such as surfactant concentration, contact time, stirring speed, stirring time, and ratio of membrane emulsion to feed volume. Results showed that optimum conditions for maximum alcohol extraction (25%) were lecithin concentration 3%, contact time 20 min, stirring speed 250 rpm and ratio of membrane emulsion to feed volume 1:2. Multistage extraction using this liquid emulsion membrane was found to completely remove alcohol from anthocyanin extract and from simulated pineapple wine in seven stages and five stages, respectively. CONCLUSION: This liquid emulsion membrane was found to be a useful method for the extraction of alcohol from aqueous feed. Copyright © 2009 Society of Chemical Industry [source] Mass Transport in Multilayer Porous Metallic Membranes , Diagnosis, Identification and ValidationCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 4 2009V. Edreva Abstract For a reliable description of mass transfer in membrane reactors the multilayer structure of the membrane is essential. This paper discusses methods which are sufficient to distinguish between homogeneous and composite membranes, and some others which are not. Different mass transport experiments (single gas permeation, isobaric diffusion, transient diffusion) with a porous metallic membrane consisting of two layers and the dusty gas model were used for this purpose. Simultaneous identification of mass transport parameters of both layers was achieved by modern optimization techniques on single gas permeation data. These parameters were validated by isobaric or transient diffusion measurements. [source] Porphyrin-Functionalized Dendrimers: Synthesis and Application as Recyclable Photocatalysts in a Nanofiltration Membrane ReactorCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2005Suhas A. Chavan Dr. Abstract The convergent synthesis of a series of porphyrin-functionalized pyrimidine dendrimers has been accomplished by a procedure involving the nucleophilic aromatic substitution (NAS) as a key reaction step. The resulting dendritic porphyrin catalysts show high activity in the light-induced generation of singlet oxygen (1O2) from ground-state oxygen. These materials are synthetically useful photosensitizers for the oxidation of various olefinic compounds to the corresponding allylic hydroperoxides. Catalytic activities and regio- and stereoselectivities of the dendritic photosensitizers are comparable to those observed for mononuclear porphyrin catalysts. Recycling of the dendrimer-enlarged homogeneous photocatalysts was possible by solvent-resistant nanofiltration (SRNF) by using an oxidatively stable membrane consisting of a polysiloxane polymer and ultrastable Y zeolite as inorganic filler. Moreover, this membrane technology provides a safe way to isolate the hydroperoxide products under very mild conditions. The membrane showed high retention for the macromolecular catalysts, even in chlorinated solvents, but some oxidative degradation of the porphyrin units of the dendrimer was observed over multiple catalytic runs. [source] | |||||||||||||