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331.
Yuchen Sun Yuqing Lin Shengyao Wang Zhe Yang Lei Zhang Hideto Matsuyama 《应用聚合物科学杂志》2021,138(3):49711
The application of “active-layer-facing-draw-solution” (AL-DS) mode, which allows a considerably high water flux in forward osmosis (FO) processes, is hindered by severe fouling occurring within the porous support of the FO membranes. We designed a series of “three-dimensionally” antifouling FO membranes by an extremely convenient and scalable approach, by using in situ reduced aliphatic polyketone (PK) membranes (rPK) and the silver-nanoparticles-immobilized rPK-Ag membranes as the substrates for thin-film composite (TFC) FO membrane preparation. This modification imparted enhanced hydrophilicity compared with the original PK-TFC membrane, without affecting the morphology and transport properties. Benefiting from the three-dimensional antifouling structure, the modified TFC membranes (i.e., rPK-TFC and rPK-Ag-TFC membranes) demonstrated excellent and comprehensive fouling resistance towards a variety of organic foulants, as well as biofouling resistance towards Escherichia coli. These results provide useful insights into the fabrication of antifouling FO membranes for water purification purposes and pressure retarded osmosis (PRO) process. 相似文献
332.
Porous poly(L ‐lactide) (PLLA) films were prepared by water extraction of poly(ethylene oxide) (PEO) from solution‐cast PLLA and PEO blend films. The dependence of blend ratio and molecular weight of PEO on the porosity and pore size of films was investigated by gravimetry and scanning electron microscopy. The film porosity and extracted weight ratio were in good agreement with the expected for porous films prepared using PEO of low molecular weight (Mw = 1 × 103), but shifted to lower values than expected when high molecular weight PEO (Mw = 1 × 105) was utilized. The maximum pore size was larger for porous films prepared from PEO having higher molecular weight, when compared at the same blending ratio of PLLA and PEO before water extraction. Differential scanning calorimetry of as‐cast PLLA and PEO blend films revealed that PLLA and PEO were phase‐separated at least after solvent evaporation. On the other hand, comparison of blend films before and after extraction suggested that a small amount of PEO was trapped in the amorphous region between PLLA crystallites even after water extraction and hindered PLLA crystallization during solvent evaporation. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 75: 629–637, 2000 相似文献
333.
Koichiro Fukuda Shinji Inoue Hideto Yoshida 《Journal of the American Ceramic Society》2003,86(1):112-114
Four types of tricalcium aluminate solid solutions with different concentrations of Na2 O and SiO2 were prepared and examined using an electron probe microanalyzer. The atomic ratios, including those determined in a previous study, were derived from the oxide compositions and provided excellent correlations between Ca and Na + Si (i.e., Ca = 3.003 − 0.48[Na + Si]), and Al and Si (Al = 1.997 − 1.02Si). Because the replacement reactions, Ca2+ ↔ 2Na+ and Ca2+ + 2Al3+ ↔ 2Si4+ , independently occur within the same crystal, these reactions have been simply combined together to generate a new formula, Na2 x Ca3− x − y (Al1− y Si y )2 O6 , where x is the amount of Ca substituted by Na, and y is the amount of Al substituted by Si. This formula leads to the equations Ca = 3 − 0.5[Na + Si] and Al = 2 − Si, which nicely account for the constrained chemical variation of the actual solid solutions with 0 ≤ x < 0.049 and 0 ≤ y < 0.073. 相似文献
334.
335.
Takeru Osawa Hirotoshi Asano Tota Mizuno Akio Nozawa Hisaya Tanaka Syusaku Nomura Toshikazu Okazaki Hideto Ide 《Artificial Life and Robotics》2016,21(1):5-10
This study aims to evaluate physiological and psychological states using near infrared spectroscopy in noise environments with low or high frequencies. Our system assumes that noise affects brain activity in the frontal lobe. In order to evaluate the subject’s states in a noise environment, we constructed an experimental system that measures the subject’s states. The experimental method adopted here was borrowed from our previous studies. In the present study, we collected experimental data about the subject’s unpleasant or pleasant experiences by producing a noise environment with low and high frequencies. We conclude that noises with low or high frequencies affect our psychological states as well as brain activity in the frontal lobe. 相似文献
336.
Yu You Makoto Ohtsuka Hideto Miyake Hiroyuki Fukuyama 《Journal of the American Ceramic Society》2014,97(12):3781-3786
The growth of AlN crystals on c‐plane 6H–SiC substrates by thermal nitridation of Al2O3 pellets in the presence of graphite and ZrO2 was demonstrated. Addition of graphite and ZrO2 effectively accelerated the evaporation of Al2O3, yielding c‐axis oriented AlN films on SiC substrates. The SiC substrate was severely deteriorated at 2173 K, which produced a porous interface between the AlN film and substrate, resulting in low‐quality AlN crystals. The deterioration of SiC was successfully suppressed by introducing a pre‐deposited homo‐buffer layer, allowing two‐dimensional‐like growth of AlN. The buffer layer promoted the formation of a high‐quality AlN film. At 2173 K, the full‐width at half maximum of the X‐ray rocking curves of the (0002) and (10–10) planes of the AlN film was 360 and 425 arcsec, respectively. 相似文献
337.
In the CaO-SiO2-Al2O3-Fe2O3 pseudoquaternary system, the solid solutions of Ca2(AlxFe1−x)2O5, with x<0.7 (ferrite), Ca2SiO4 (belite), Ca3Al2O6 (C3A) and Ca12Al14O33 (C12A7), were crystallized out of a complete melt during cooling at 8.3 °C/min. Upon cooling to 1370 °C, both the crystals of ferrite with x=0.41 and belite would start to nucleate from the melt. During further cooling, the x value of the precipitating ferrite would progressively increase and eventually approach 0.7. At ambient temperature, the ferrite crystals had a zonal structure, the x value of which successively increased from the cores toward the rims. The value of 0.45 was confirmed for the cores by EPMA. The chemical formula of the rims was determined to be Ca2.03[Al1.27Fe0.68Si0.02]Σ1.97O5 (x=0.65). As the crystallization of ferrite and belite proceeded, the coexisting melt would become progressively enriched in the aluminate components. After the termination of the ferrite crystallization, the C3A and belite would immediately crystallize out of the melt, followed by the nucleation of C12A7. The C12A7 accommodated about 2.1 mass% Fe2O3 in the chemical formula Ca12.03[Al13.61Fe0.37]Σ13.98O33, being free from the other foreign oxides (SiO2 and P2O5). 相似文献
338.
Development of antifouling poly(vinyl chloride) blend membranes by atom transfer radical polymerization 下载免费PDF全文
In this study, antifouling poly(vinyl chloride) (PVC) blend membranes were prepared by blending the PVC based amphiphilic copolymer PVC‐g‐poly(hydroxyethyl methacrylate) (PVC‐g‐PHEMA), synthesized by atom transfer radical polymerization (ATRP), into the hydrophobic PVC matrix via the nonsolvent‐induced phase separation method. The in situ ATRP reaction solutions were also used as the blend additives to improve membrane performance. Attenuated total reflectance–Fourier transform infrared spectroscopy and X‐ray photoelectron spectroscopy indicated that the blend membranes based on the two blend routes exhibited similar surface chemical compositions. The membrane morphology and surface wettability were determined by scanning electronic microscopy and water contact angle measurement, respectively. The blend membranes showed improved water permeability, comparable rejections and enhanced antifouling properties compared with the pure PVC membrane. The PVC blend membranes also had excellent long‐term stability in terms of chemical compositions and fouling resistance. The results demonstrated that ATRP was a promising technique to synthesize amphiphilic copolymer and prepare stable blend antifouling membranes. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45832. 相似文献