نتایج جستجو برای: fe mcm 41
تعداد نتایج: 171392 فیلتر نتایج به سال:
The discovery of mesoporous molecular sieves, MCM-41, which possesses a regular hexagonalarray of uniform pore openings, aroused a worldwide resurgence in this field. This is not onlybecause it has brought about a series of novel mesoporous materials with various compositionswhich may find applications in catalysis, adsorption, and guest-host chemistry, but also it hasopened a new avenue for cr...
The mesoporous molecular sieve MCM-41 was covalently grafted with 3-chloropropyl trimethoxylsilane and then was reacted with [Cr(salpr)(H2O)]Cl, (salpr = N,N'-bis(3-salicylidenaminopropyl)amine) to afford MCM-41 containing Cr(salpr) moiety, Cr(salpr)MCM-41. Powder X-ray diffraction and nitrogen adsorption-desorption analyses revealed that not only the textural characteristics of the support wer...
Ti-MCM-41 was synthesized at pH 3, 7 and 11. The titanium content was determined by AAS and found to be 4%, 3.2% and 4.5%, respectively. In order to increase the titanium content in Ti-MCM-41, Ti(IV) ions were grafted onto Ti-MCM-41 using TiCl4 in toluene and Ti(OBu)4 in ethanol. The incorporation of Ti was determined to be 28% and 30%, respectively. The oxidation of olefins such as cyclopenten...
در این پایاننامه مشتقات پیران و پیریدین در حضور کاتالیستهای اسیدی جامد بر پایه سیلیکای مزوپور سنتز شدهاند. کاتالیست zro2/fe3o4@ mcm-41 سولفاته شده (so42-/zro2/fe3o4@ mcm-41) در شرایط مختلف سنتز شده است و مشخصات آن با روشهای ft-ir، xrd و sem تعیین گردیده است. نتایج بهدست آمده نشاندهنده وجود ساختار مزوپور کاتالیست است. فعالیت کاتالیستی so42-/zro2/fe3o4@ mcm-41 با نسبت 9/1 si/zr=و 5/1si/...
Nanoporous materials such as Mobil composite material number 41 (MCM-41) are attractive for applications such as catalysis, adsorption, supports, and carriers. Green synthesis of MCM-41 is particularly appealing because the chemical reagents are useful and valuable. We report on the eco-friendly synthesis of MCM-41 nanoporous materials via multi-cycle approach by re-using the non-reacted reagen...
A new and simple method for preparing confined copper nickel nanoparticles by thermal treatment of their respective cations inside Mobil Composition Matter 41 (MCM–41) hydrophobic nanopores is presented here. Surface modified MCM–41 materials were impregnated using high-pressure with II (Cu II) or (Ni aqueous solutions. After pressure release washing, the remaining metal cations, exclusively wi...
Mesoporous MCM-41 molecular sieves substituted with various amounts of Cu(II) and Al(III) were synthesized by the hydrothermal method. The resultant materials were characterized by XRD, XANES, surface area and pore size measurement, EPR and 27Al solid state NMR. The Cu(II)-substituted MCM-41 was found to be an efficient catalyst in the oxidation of trimethylphenol (TMP) to trimethylbenzoquinone...
سنتز و تعیین مشخصات جاذب نانوساختار mcm-41 اصلاح شده با zncl2 به منظور حذف یون جیوه از محلول های آبی
در این پایان نامه، سنتز جاذب مزوپور mcm-41 و اصلاح سطح آن به وسیله ی نمک فلزی zncl2 به منظور حذف یون hg(ii) از محلول های آبی انجام شد. سنتز mcm-41 به روش هیدروترمال در حضور اتانول به عنوان حلال و ماده فعال سطحی کمکی و در محیط قلیایی انجام پذیرفت. جاذب معدنی zncl2-mcm-41 به روش پیوند کووالانسی با توزیع مواد در حلال تولوئن و از اندرکنش بین ذره های zncl2 با گروه های سیلانول روی دیواره ی حفره های m...
This work reports a new method to covalently attach calix[4]arene derivatives onto MCM-41, using a diisocyanate as a linker. The modified mesoporous silicates were characterized by fourier transform infrared spectroscopy (FTIR), thermal analysis (TGA) and elemental analysis. The FTIR spectra and TGA analysis verified that the calix[4]arene derivates are covalently attached to the mesoporous sil...
Recently, flufenamic acid (FFA) was discovered among fenamates as a free radical scavenger and gap junction blocker; however, its effects have only been studied in cancer cells. Normal cells in the surroundings of a tumor also respond to radiation, although they are not hit by it directly. This phenomenon is known as the bystander effect, where response molecules pass from tumor cells to normal...
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