نتایج جستجو برای: غربال مولکولی mcm 41

تعداد نتایج: 106087  

Journal: :Photochemical & photobiological sciences : Official journal of the European Photochemistry Association and the European Society for Photobiology 2002
Isabel Casades Mercedes Alvaro Hermenegildo García Manoj Narayana Pillai

The influence of the chemical composition and silylation of mesoporous MCM-41 materials on the photochromic behaviour of adsorbed spiropyran (BIPS) and 6-nitrospiropyran was studied. Upon incorporation, the spiropyrans underwent ring opening to form either zwitterionic merocyanine or its corresponding O-protonated form. In all silica MCM-41 or in the MCM-41 containing aluminium, the O-protonate...

2003
Tao Li Soofin Cheng Jyh-Fu Lee Ling-Yun Jang

Molybdenum and zirconium mixed oxides were supported on siliceous MCM-41 mesoporous material. The resultant materials were characterized with various techniques such as X-ray diffraction (XRD), nitrogen adsorption, Transmission electron microscopy (TEM), XANES, NH3-TPD, and Diffuse reflectance infrared Fourier transform spectra (DRIFTS) of pyridine. It was found that the well-ordered channeling...

Journal: :Journal of colloid and interface science 1998
Neimark Ravikovitch Grün Schüth Unger

Methods of nonlocal density functional theory (NLDFT), proposed recently for predictions of adsorption equilibrium and calculations of pore size distributions in micro- and mesoporous materials, were tested on reference MCM-41 materials. Five newly synthesized MCM-41 adsorbents with presumably uniform pore channels varying from 32 to 45 Å were characterized by X-ray diffraction (XRD), nitrogen ...

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده علوم پایه 1391

نانو تکنولوژی رشته ای است که به سرعت در حال پیشرفت است و شامل ساخت و استفاده از مواد و تجهیزات در مقیاس نانو می باشد. مواد مختلفی حاوی ترکیبات نانو نقش مهمی در علم و فناوری نوین از جمله علم داروسازی ایفا می کند. mcm-41 یکی از مواد مزوپور امزوزه به عنوان حامل دارو بکار می رود.مواد آرایش یافته mcm-41 دارای شبکه ای از مجراها و فضاهای تهی با اندازه مناسب در مقیاس نانو (nm50-2 ) است.ساختار این منفذ...

Journal: :Environmental science & technology 2013
Liang-Yi Lin Hsunling Bai

An efficient and economic approach is proposed for the fast and direct recovery of silica materials from photonic waste powder. Unlike the conventional alkaline fusion method for the extraction of silica from waste materials, this method possesses advantages of a rapid and low-energy-consumed process with total recovery yield. The obtained mesoporous silica material, denoted as MCM-41(DU)-F, wa...

2006
Edwin Alarcón Aída Luz Villa Consuelo Montes de Correa

Introduction Nopol is an unsaturated alcohol useful for the synthesis of fragrances, pesticides and household products [1]. It has been traditionally obtained by condensation of β-pinene and paraformaldehyde at high temperatures or using homogeneous Lewis acid catalysts [2]. Recently, heterogeneous catalysts: FePO4, Sn-MCM-41 and Zn-Al-MCM-41, have been reported for nopol synthesis under mild c...

2013
Hyeonhee Choi Jung-Hyun Bae Do Heui Kim Young-Kwon Park Jong-Ki Jeon

MCM-41 was used as a support and, by using atomic layer deposition (ALD) in the liquid phase, a catalyst was prepared by consecutively loading titanium oxide and vanadium oxide to the support. This research analyzes the effect of the loading amount of vanadium oxide on the acidic characteristics and catalytic performance in the dehydration of butanol. The physical and chemical characteristics o...

2017
Wenjie Zhu Jingxuan Wang Di Wu Xitong Li Yongming Luo Caiyun Han Wenhui Ma Sufang He

Mesoporous silica materials (MSMs) of the MCM-41 type were rapidly synthesized by microwave heating using silica fume as silica source and evaluated as adsorbents for the removal of Cu2+, Pb2+, and Cd2+ from aqueous solutions. The effects of microwave heating times on the pore structure of the resulting MSMs were investigated as well as the effects of different acids which were employed to adju...

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