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101.
S.C. Ray Arindam SahaS.K. Basiruddin S.S. RoyNikhil R. Jana 《Diamond and Related Materials》2011,20(3):449-453
In this work, we have developed a polyacrylate-coated graphene-oxide and then chemically reduced them into graphene. We found that polyacrylate coating can improve the colloidal stability of both graphene-oxide/graphene. They show good colloidal stability in different aqueous buffer solution with pH ranging from 5 to 10, and these solutions are stable for more than a month. The polyacrylate-coated grapheme oxide/graphene has been characterized by X-ray photoemission spectroscopy (XPS) and micro-Raman spectroscopy. Based on good colloidal stability, this graphene-oxide/graphene is most suitable for the biological application. 相似文献
102.
Catalytic ozone decomposition reaction was used to study the performance of a 76 mm i.d. and 5.8 m high gas–solid circulating fluidized bed (CFB) downer reactor. Optical fiber probes and an ultraviolet (UV) ozone analyzer were used to obtain comprehensive information about local solids holdup and ozone concentration profiles at different axial and radial positions at superficial gas velocity of 2–5 m/s and solids circulation rates of 50 and 100 kg/m2 s. Axial ozone concentration profiles significantly deviated from the plug-flow behavior, with most conversion occurring in the entrance region or flow developing zone of the downer reactor. Strong correlation was observed between the spatial distributions of solids and extent of reaction; higher local solids holdups cause lower ozone concentrations due to higher reaction rates. Radial gradients of the reactant (ozone) concentrations increased in the middle section of the downer, and decreased with increasing superficial gas velocity and solids circulation rate. Contact efficiency, a measure of the interaction between gas and solids indicated high efficiency in the flow developing zone and decreased with height in the fully developed region. 相似文献
103.
Pallavi Mukherjee Chaitali Chanda Moumita Bhaumik Madhurima Ghosh Jaweria Sharmin Poulami Datta Srimoyee Banerjee Parthasarathi Barat Ashoke Ranjan Thakur Lalit Mohan Gantayet Indranil Mukherjee Shaon Ray Chaudhuri 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2018,93(5):1279-1289
104.
Gamma radiation aging of EVA/EPDM blends: Effect of vinyl acetate (VA) content and radiation dose on the alteration in mechanical,thermal, and morphological behavior 下载免费PDF全文
Bhuwanesh Kumar Sharma Kumar Krishnanand P.A. Mahanwar K.S.S. Sarma Subhendu Ray Chowdhury 《应用聚合物科学杂志》2018,135(18)
A series of ethylene vinyl acetate (EVA)/ethylene‐propylene diene elastomer (EPDM) blends (50/50 ratio) with four types of EVAs were prepared using brabender type batch mixer followed by compression molding. All compression‐molded samples were exposed to gamma radiation at 500, 1000, and 1500 kGy doses and were subjected to mechanical, compression set, thermal and morphological test. The % retention in tensile strength, elongation, and hardness were found higher for higher vinyl acetate (VA) containing radiation aged EVA/EPDM blends. The compression set value was decreased with increase of VA content. The thermal degradation kinetics of high VA containing irradiated blend (EVA40/EPDM) (EVA40 is 40%VA containing EVA) was found slower than those of lower VA containing blend (EVA18/EPDM). The surface morphology for EVA18/EPDM sample was transformed into more irregular one with more cracks and fragmented segments by aging at 1500 kGy dose while surface for EVA40/EPDM sample was found comparatively smooth, fine, and continuous with very few cracks and fragmented parts at similar dose. Thus, from the measured properties and morphology, it was revealed that the degree of degradation of blends kept on decreasing with increase in VA content. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 46216. 相似文献
105.
Styrene butadiene rubber (SBR) was efficiently cured (crosslinked) by using sulfur to accelerator ratio less than unity. This cured SBR was further compounded with carbon black filler (grade N330) with three different doses i.e., 5, 10, and 20 wt % of filler to form three different filled and crosslinked membranes, i.e., SBR5, SBR10, and SBR20. These filled rubber membranes and one unfilled but efficiently cured membrane, i.e. SBR0, were used for pervaporative removal of pyridine from its mixtures with water. The filled membranes were found to show better selectivity and mechanical properties but lower flux than the unfilled membrane. All of these membranes showed reasonably good range of flux and pyridine selectivity. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 相似文献
106.
107.
Li Xing David C. Blakemore Arjun Narayanan Ray Unwalla Frank Lovering R. Aldrin Denny Huanyu Zhou Mark E. Bunnage 《ChemMedChem》2015,10(4):715-726
Anisole and fluoroanisoles display distinct conformational preferences, as evident from a survey of their crystal structures. In addition to altering the free ligand conformation, various degrees of fluorination have a strong impact on physicochemical and pharmacokinetic properties. Analysis of anisole and fluoroanisole matched molecular pairs in the Pfizer corporate database reveals interesting trends: 1) PhOCF3 increases log D by ~1 log unit over PhOCH3 compounds; 2) PhOCF3 shows lower passive permeability despite its higher lipophilicity; and 3) PhOCF3 does not appreciably improve metabolic stability over PhOCH3. Emerging from the investigation, difluoroanisole (PhOCF2H) strikes a better balance of properties with noticeable advantages of log D and transcellular permeability over PhOCF3. Synthetic assessment illustrates that the routes to access difluoroanisoles are often more straightforward than those for trifluoroanisoles. Whereas replacing PhOCH3 with PhOCF3 is a common tactic to optimize ADME properties, our analysis suggests PhOCF2H may be a more attractive alternative, and greater exploitation of this motif is recommended. 相似文献
108.
This article evaluates the role of cellulosic fillers in a synthetic polymer matrix like polymethylmethacrylate (PMMA) when incorporated by in situ suspension polymerization technique. Cellulose micro/nanofibers (CNF) were extracted from jute fibers and chemically modified with maleic anhydride (MACNF) to increase their interfacial compatibility with PMMA by participation of the MA moiety in the free radical polymerization with MMA. The effect of incorporating MACNF on the physical and mechanical properties of the PMMA matrix was investigated. Optical transparency was retained in the in situ prepared PMMA/cellulose composites (IPMC) similar to that of unreinforced PMMA. Another set of PMMA/cellulose composites was prepared by dispersing MACNF in PMMA matrix by ex situ solution dispersion method (EPMC). The modification of CNF with MA significantly improved the filler/matrix interfacial compatibility and in situ polymerization technique further enhanced the properties of the composites. The high moisture absorption tendency, which is a major drawback of the cellulose filled composites, remarkably reduced in IPMC. POLYM. COMPOS., 36:1748–1758, 2015. © 2014 Society of Plastics Engineers 相似文献
109.
Ansuman Barman Nilesh Kumar Shrivastava Bhanu Bhusan Khatua Bidhan Chandra Ray 《Polymer Composites》2015,36(12):2157-2166
Here we report the preparation and characterization of a green composite based on high‐density polyethylene and Kaans grass (Saccharum spontaneum). The composites were prepared by conventional melt‐mixing method, using maximum loading of Kaans grass in powder form (KG‐filler) to achieve acceptable range of required properties. Maleic anhydride grafted polyethylene was used as compatibilizer to achieve effective interaction for improved surface adhesion which was confirmed by FT‐IR spectroscopy. Morphological studies revealed good interaction between the base polymer matrices and the KG‐fillers that improved the mechanical and thermal properties of the composites up to certain (10 phr) KG‐filler loading. Study on water absorption property revealed moderate increase in weight at higher KG‐filler loadings. Thermogravimetric analysis (TGA) and melt flow index (MFI) studies indicated retention of thermal stability and flow property of the HDPE/KG‐filler composite at lower filler loadings. POLYM. COMPOS., 36:2157–2166, 2015. © 2014 Society of Plastics Engineers 相似文献
110.
Mahendra Pakala Heather Walls Ray Y. Lin 《Journal of the American Ceramic Society》1997,80(6):1477-1484
Calcia-stabilized zirconia films were deposited on the surface of silicon 111 wafers using radio frequency (rf) magnetron sputter deposition. Deposition was conducted at substrate temperatures that varied in the range of 80°–900°C. X-ray diffractometry results showed that all the films consisted of cubic zirconia. The fracture surface morphology and etched surfaces of the films were studied using scanning electron microscopy (SEM). Depending on the deposition temperature, the structure of the film was either columnar or equiaxed. The transition temperature from the columnar structure to the equiaxed structure was at a ratio of deposition temperature to melting temperature of } 0.42. The microhardness of the films was evaluated using a developed model that is based on the plastic zone analysis below a diamond (Vickers) indentor. From this model, the microhardness was found to increase as the deposition temperature increased, which was probably because the hardness of ceramic materials decreases as the defect concentration increases. 相似文献