• A study on methanation of carbon monoxide over catalysts NiO/TiO2 AND NiO/γ-Al2O3A study on methanation of carbon monoxide over catalysts NiO/TiO2 AND NiO/γ-Al2O3

    Abstract. The catalyst 7.5% NiO/TiO2 and seven samples of NiO/γ-Al2O3 with NiO content from 7.5% to 60% have been obtained and studied. Physico-chemical characteristics of the catalysts were determined by methods of Adsorption (BET), X-ray Diffraction (XRD), TemperatureProgrammed Reduction (TPR) and Hydrogen Pulse Titration. The catalytic properti...

    pdf16 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 413 | Lượt tải: 0

  • Preparation of superabsorbent polymers by the inverse suspension methodPreparation of superabsorbent polymers by the inverse suspension method

    Abstract. The superabsorbent polymers based on acrylic acid have been prepared in the presence of ammonium persulfate (APS) as initiator and N,N-methylene- bis- acrylamide (MBA) as crosslinking agent. The suspension polymerisation occurred in aqueous drops dispersed in toluene and stabilised by sorbitan monooleate. Some effects on the swelling de...

    pdf6 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 478 | Lượt tải: 0

  • Study on preparation of blends based on poly(vinyl chloride), nitrile - butadiene rubber, natural rubber and polyethyleneStudy on preparation of blends based on poly(vinyl chloride), nitrile - butadiene rubber, natural rubber and polyethylene

    Abstract. The blends based on polyvinyl chloride (PVC), nitrile-butadiene rubber (NBR), natural rubber (NR) and polyethylene (PE) were made by three different methods. The mechanical properties of these blends in dependence of mixing time and temperature were characterized. The result showed that the two-step blending method, where PVC and NBR ...

    pdf6 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 503 | Lượt tải: 0

  • The phase transformation in the crystallization process of Fe-mordenite zeoliteThe phase transformation in the crystallization process of Fe-mordenite zeolite

    Abstract. In the present paper, we reported the influence of the crystallization time on the crystallinity of the Fe-mordenite zeolite (Fe- MOR). The obtained results showed that, in order to reach the high crystallinity of zeolite the optimal duration of crystallization was about 36 h. When crystallization time increased from 48h to 72h, there...

    pdf9 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 390 | Lượt tải: 0

  • Preparation, optical properties and energy transfer of Y2O3: rare earth (RE: Tb,Eu, Er, Yb) nanophosphorsPreparation, optical properties and energy transfer of Y2O3: rare earth (RE: Tb,Eu, Er, Yb) nanophosphors

    Abstract. This paper describes the preparation, optical properties and the role of the concentration of rare earth ions (RE: Eu, Er, Tb, Yb) as active centers in the energy transfer of Y2O3: RE nanophosphors. The materials are prepared by the combustion method using urea or glycine. Nanoparticles can be prepared with sizes ranging from 5 to 100 n...

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  • Study on the structure and properties of polypropylene/clay nanocompositesStudy on the structure and properties of polypropylene/clay nanocomposites

    Abstract. Polypropylene/ maleic anhydride /organic montmorillonite nanocomposites (PP/ MA/ Org-MMT) have been prepared via direct melt intercalation in an internal mixer. Maleic anhydride (MA) was used as a compatibilizer to improve the dispersability of the clay. The structures of nanocomposites have been characterized by X-ray diffraction (XRD...

    pdf8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 398 | Lượt tải: 0

  • Influence of substitution of the magnetic 3d metals for mn in perovskite La0.67Ca0.33Mn0.90TM0.10O3Influence of substitution of the magnetic 3d metals for mn in perovskite La0.67Ca0.33Mn0.90TM0.10O3

    Abstract. Influence of substitution of 3d metals for Mn on properties of La0.67Ca0.33Mn0.9 TM0.1O3 (TM = Fe, Co, Ni) compounds was studied. Ferromagnetic – paramagnetic and metals – insulator transitions were significantly affected by Mn-site substitution. However, no observable difference was found in their crystal structure from X-ray diffract...

    pdf12 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 376 | Lượt tải: 0

  • Anharmonic effective potential, local force constant and correlation effects in XAFS of bcc crystalsAnharmonic effective potential, local force constant and correlation effects in XAFS of bcc crystals

    Abstract. Analytical expressions for the anharmonic effective potential, local force constant, Displacement-displacement Correlation Function (DCF) CR and Debye-Waller factor described by the Mean Square Relative Displacement (MSRD) σ2 and by the Mean Square Displacement (MSD) u2of bcc crystals in the X-ray Absorption Fine Structure (XAFS) have ...

    pdf8 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 436 | Lượt tải: 0

  • Nghiên cứu chế tạo và một số tính chất của sợi polyvinylidene fluoride bằng phương pháp phun kéo sợi điện trườngNghiên cứu chế tạo và một số tính chất của sợi polyvinylidene fluoride bằng phương pháp phun kéo sợi điện trường

    Tóm tắt: Phương pháp phun kéo sợi điện trường (electrospinning) cho phép chế tạo các sợi polymer với đường kính trong khoảng vài chục nm đến vài µm. Trong nghiên cứu này, các yếu tố ảnh hưởng đến hình thái học, đường kính sợi trung bình và sự phân bố đường kính sợi polyvinylidene fluoride (PVDF) chế tạo bằng phương pháp electrospinning được đá...

    pdf6 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 481 | Lượt tải: 0

  • Tổng hợp các dẫn xuất 2-benzylbenzoxazole sử dụng hạt nano gắn dung môi eutectic sâu làm xúc tácTổng hợp các dẫn xuất 2-benzylbenzoxazole sử dụng hạt nano gắn dung môi eutectic sâu làm xúc tác

    TÓM TẮT Dung môi eutectic sâu cố định trên hạt nano từ tính (DES@MNP) được điều chế từ [Urea]4[ZnCl2] mang lên các hạt nano từ tính Fe3O4 thông qua 3-chloropropyltrimethoxysilane như một cầu nối. Cơ cấu của xúc tác được xác định bằng các phương pháp hóa lí như SEM, TEM, VSM, EDX, IR, XRD, TGA. Trong nghiên cứu này, hợp chất dị hoàn 2-benzylbenz...

    pdf10 trang | Chia sẻ: thanhle95 | Ngày: 07/07/2021 | Lượt xem: 421 | Lượt tải: 0