The Experts below are selected from a list of 6552 Experts worldwide ranked by ideXlab platform
Ahmad Fauzi Ismail - One of the best experts on this subject based on the ideXlab platform.
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novel hydrophobic pvdf aptes go nanocomposite for natural gas pipelines coating
Journal of Natural Gas Science and Engineering, 2017Co-Authors: S J Chiong, Pei Sean Goh, Ahmad Fauzi IsmailAbstract:Abstract Polyvinylidene fluoride (PVDF) nanocomposites were successfully prepared by solvent casting approach using graphene oxide (GO) and 3-aminopropyltriethoxysilane-graphene oxide (APTES-GO) as nanofillers. Field emission scanning electron microscope (FESEM) revealed that the PVDF nanocomposites exhibited features of Symmetric Membrane. Incorporation of 0.4 wt% of APTES-GO into the PVDF matrix led to a significant decrease in wettability with water contact angle (CA) of 102° as compared to 62° for 0.4 wt% GO and 80° for neat PVDF. PVDF/APTES-GO has increased 2350% in tensile modulus as compared to 75% increased in PVDF/GO nanocomposite. Carbon steel plate, which has similar properties with commercial carbon steel pipelines was used in the salt spray and acid immersion tests. PVDF/APTES-GO nanocomposite coating was found to exhibit excellent corrosion protection and good adhesion property than other coatings in corrosive environments.
Xiaoyao Tan - One of the best experts on this subject based on the ideXlab platform.
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mixed conducting Membranes macrostructure related oxygen permeation flux
Aiche Journal, 2010Co-Authors: Barbara Zydorczak, Xiaoyao TanAbstract:The influence of the macrostructures of LSCF hollow fiber Membranes on oxygen permeation flux was investigated experimentally and theoretically. According to the results, aSymmetric Membranes perform differently toward oxygen permeation depending on their sintering outcome. If both, outer and inner surfaces of the aSymmetric Membrane are fully densified, finger-like pores become dead volume, which has adverse effects, and the oxygen permeation flux is similar to that of the Symmetric Membrane. This implies that the improved bulk diffusion due to the reduced Membrane thickness is compromised by the additional exchange reaction resistance from the enclosed macrovoids in the aSymmetric Membranes. However, when one surface of the Membrane is fully open, then oxygen permeation is greatly enhanced mainly due to the remarkable increase in the effective surface area for surface exchange reactions. In order to evaluate the actual surface exchange area due to the presence of the porous structure within the aSymmetric Membranes, a correction factor α, has been introduced in the theoretical analysis presented. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Liao Ping Cheng - One of the best experts on this subject based on the ideXlab platform.
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formation of porous poly vinylidene fluoride Membranes with Symmetric or aSymmetric morphology by immersion precipitation in the water tep pvdf system
European Polymer Journal, 2006Co-Authors: Dar Jong Lin, Hsu Hsien Chang, Tzung Chin Chen, Yi C Lee, Liao Ping ChengAbstract:Abstract The phase equilibrium boundaries of the Membrane forming system, water/triethyl phosphate (TEP)/PVDF, at 25 °C were determined experimentally using cloud-point and equilibrium absorption methods. Based on the phase diagram, appropriate dope and bath compositions were selected to prepare microporous Membranes by means of the isothermal immersion–precipitation technique. As a metastable casting dope with respect to crystallization was adopted, the formed Membranes exhibited a uniform cross-section composed of interlocked crystal elements coexisting with the network of continuous pores, as was revealed by high resolution FESEM imaging. Morphologies of the Membranes’ top surfaces were found to depend heavily on the bath strength, which was controlled by the TEP content. By changing the bath gradually from pure water to 70% TEP, the top surface evolved from a dense skin (aSymmetric Membrane) to a totally porous morphology (Symmetric Membrane). Wide angle X-ray diffraction analysis indicated that PVDF crystallized into α-type structure for all of the synthesized Membranes. The crystallinity as determined from diffraction peak deconvolution was ≈65%, which value was confirmed by Differential Scanning Calorimetry (DSC). The obtained thermograms also showed a similar melting peak temperature (Tm ≈ 169 °C) for all Membranes. Furthermore, water fluxes and tensile strengths of the Membranes were measured. The results were found to correlate with the morphologies of the Membranes.
Tong Liu - One of the best experts on this subject based on the ideXlab platform.
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a dual phase bilayer oxygen permeable Membrane with hierarchically porous structure fabricated by freeze drying tape casting method
Journal of Membrane Science, 2016Co-Authors: Tong Liu, Yu Chen, Shumin Fang, Libin Lei, Yao Wang, Cong Ren, Fanglin ChenAbstract:Abstract A bilayer oxygen permeable Membrane consisting of hierarchically porous Ce0.9Gd0.1O1.95-(La0.8Sr0.2)0.95MnO3−δ (GDC-LSM) support and dense GDC-LSM film has been fabricated by a combined freeze-drying tape-casting and screen-printing method followed by co-sintering. Two dimensional (2D) SEM-BSE and reconstructed three dimensional (3D) XCT images indicated that the porous GDC-LSM support (870-µm-thick) contains graded straight pores with low tortuosity factor, promoting fast gas diffusion in the support, while the dense GDC-LSM film with a thickness of 30 µm provides a short path for the bulk transport of oxygen ions and electrons. However, the oxygen flux of the aSymmetric GDC-LSM Membrane is only 81% higher than that of the 900-µm-thick dense GDC-LSM Symmetric Membrane, indicating that the oxygen transport becomes limited by the surface oxygen exchange process for the GDC-LSM aSymmetric Membrane with a 30-µm-thick dense GDC-LSM film. When the permeate side surface is modified with Ce0.8Sm0.2O1.9-La0.6Sr0.4Co0.2Fe0.8O3−δ (SDC-LSCF), the oxygen permeation flux of the GDC-LSM aSymmetric Membrane is significantly enhanced from 0.105 to 0.780 mL cm−2 min−1, while the activation energy is substantially decreased from 219.6±8.7 to 138.1±3.3 kJ mol−1, due to enhanced surface oxygen exchange kinetics. Furthermore, the coated aSymmetric Membrane shows 1100% higher oxygen flux than the coated Symmetric Membrane. When the sweep gas is switched from helium to CO2, although the adsorption of CO2 on the permeate side surface leads to a slight decrease in oxygen permeation flux, a high oxygen permeation flux of 0.659 mL cm−2 min−1 can still be achieved, demonstrating that the coated GDC-LSM aSymmetric Membrane is promising for oxy-fuel combustion application.
Maria Palmira Daflon Gremiao - One of the best experts on this subject based on the ideXlab platform.
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cellulose triacetate films obtained from sugarcane bagasse evaluation as coating and mucoadhesive material for drug delivery systems
Carbohydrate Polymers, 2016Co-Authors: Sabrina Dias Ribeiro, Guimes Rodrigues Filho, Andreia Bagliotti Meneguin, Fabiola Garavello Prezotti, Fernanda Isadora Boni, Beatriz Stringhetti Ferreira Cury, Maria Palmira Daflon GremiaoAbstract:Abstract Cellulose triacetate (CTA) films were produced from cellulose extracted from sugarcane bagasse. The films were characterized using scanning electron microscopy (SEM), water vapor permeability (WVP), mechanical properties (MP), enzymatic digestion (ED), and mucoadhesive properties evaluation (MPE). WVP showed that more concentrated films have higher values; aSymmetric films had higher values than Symmetric films. MP showed that Symmetric Membranes are more resistant than aSymmetric ones. All films presented high mucoadhesiveness. From the WVP and MP results, a Symmetric Membrane with 6.5% CTA was selected for the coating of gellan gum (GG) particles incorporating ketoprofen (KET). Thermogravimetric analysis (TGA) showed that the CTA coating does not influence the thermal stability of the particles. Coated particles released 100% of the KET in 24 h, while uncoated particles released the same amount in 4 h. The results highlight the CTA potential in the development of new controlled oral delivery systems.
