نتایج جستجو برای: پیش ماده teos
تعداد نتایج: 127044 فیلتر نتایج به سال:
Ordered mesoporous silicas SBA-15 with high loadings of pendant vinyl groups have been synthesized via co-condensation of tetraethoxysilane (TEOS) and triethoxyvinylsilane (TEVS) templated with a triblock copolymer.
in this research controlled coating of magnetite (fe3o4) nanoparticles with sio2 was investigated. the fe3o4 nanoparticles were synthesized via chemical co-precipitation and then coated by silica according to stober method. effects of tetra ethyl ortho silicate (teos) concentration and ethanol to teos on the coating thickness were investigated. x-ray powder diffraction, fourier transform infrar...
مقدمه: استفاده از محرک ها و ترکیبات مختلف در محیط کشت سوسپانسیون سلولی راهکار مناسبی برای افزایش و بهبود تولید متابولیت های ثانویه مهم در شرایط درون شیشه ای مهیا می کند. هدف: بررسی تأثیر ال- تیروزین و ترکیب آن با محرک های زیستی کیتوسان و اسید سالیسیلیک بر تولید تبائین در کشت سوسپانسیون سلولی گیاه خشخاش ایرانی در روزهای مختلف پس از تحریک بود. روش بررسی: غلظت های مختلف ال- تیروزین (1 و 2 میلی مول...
Samples of a commercial glass fiber FM® (Fiber Max) were used to test the efficacy of a chemical sol-gel surface treatment to enhance their bioactivity. After treatment with tetraethoxysilane (TEOS), individual fiber samples were soaked into a simulated body fluid (SBF) solution, from which they were removed at intervals of 5 and 10 days. Micrographs obtained by scanning electron microscopy (SE...
Perylenediimide functionalized bridged siloxane nanoparticles were prepared by direct hydrolysis and condensation of a perylenediimide silane precursor in the presence of a catalytic amount of tetraethoxysilane (TEOS). The sizes of the particles were controlled by adjusting organotrialkoxysilane, base, and TEOS concentrations. Using this modified Stöber method, we were able to incorporate a hig...
classical xerogels are robust, inexpensive and nontoxic materials with low-ordered nanoporous structures. in water streams where the ph is higher than the point of zero charge, the surface of classical xerogels such as tetraethoxy orthosilan (teos) xerogel is negatively charged. it was assumed that a xerogel can work as a strong adsorbent for metal ions without further modification. therefore, ...
An efficient and reusable adsorbent, namely 3-mercaptopropionic acid modified tetraethyl orthosilicate (TEOS) grafted MnFe2O4 nanoparticles (MPA-TEOS-MnFe2O4 NPs) was synthesized and used for the extraction and preconcentration of trace amount of Al (III) and Cr (III) ions in water samples. MnFe2O4 NPs were prepared by chemical c...
Abstract. The international Thermodynamic Equation of Seawater 2010 (TEOS-10) defined the enthalpy and entropy seawater, thus enabling global ocean heat content to be calculated as volume integral product in situ density, ?, potential enthalpy, h0 (with reference sea pressure 0 dbar). In terms Conservative Temperature, ?, is ?cp0?, where cp0 a constant “isobaric capacity”. However, many models ...
Ester-silica nanoparticles (NPs) were prepared using a facile two-surfactant synthesis route in neutral medium involving silica (tetraethyl orthosilicate, TEOS) and organosilica (3-(trimethoxysilyl)propyl 5-(trimethoxysilyl)pentanoate, PMe) precursors. The ester hydrolysis generates carboxylic acid groups, which confer strongly negative zeta potential to the NPs at pH. extent of during was quan...
در این تحقیق نانوکامپوزیت پلی یورتانی فوم سخت سوپر پارامغناطیسی به روش درجا سنتز شد. برای سنتز این نانوکامپوزیت، نانوذرات هسته-پوسته fe3o4@sio2 با روش سل-ژل و با پیش ماده تترا اتیل اورتو سیلیکات (teos) سنتز شدند و با آنالیز میکروسکوپ الکترونی عبوری (tem) و طیف سنجی مادون قرمز تبدیل فوریه (ftir) مشخصه یابی شدند. فاز کریستالی مورد نظر در هسته ی مگنتیت (fe3o4) و نانو ذرات هسته-پوسته به روش آنالیز ...
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