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Register a new userPreparation and characterization of alumina supported with sulfate ions and molybdenium
تحضير و توصيف الألومينا المحملة بالكبريتات و الموليبدينيوم
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حضرت عينات من الألومينا المحملة بأيونات الكبريتات و الموليبدينيوم بنسب مختلفة بطريقة النقع. عولجت العينات المحضرة عند درجة حرارة 550°C لمدة 6 ساعات . يؤدي تحميل الكبريتات و الموليبدينيوم إلى تناقص المساحة السطحية النوعية للألومينا و يكون التناقص أكبر في حالة الموليبدينيوم. تؤدي عملية التحميل إلى تناقص حجم المسام الكلي و ازدياد نصف قطر المسام الوسطي. بين طيف الأشعة السينية XRD أن وجود الكبريتات و الموليبدينيوم لا يغير في البنية البلورية للألومينا . كما بين طيف الأشعة تحت الحمراء FTIR وجود ارتباط بين الكبريتات و الموليبدينيوم مع سطح الألومينا. يتناقص الفاقد الوزني للألومينا عند التحميل بالكبريتات و الموليبدينيوم, و تتفكك الكبريتات عند الدرجة 700°C~ بينما يتفكك أوكسيد الموليبدينيوم عند الدرجة 800°C~ كما يظهر من دراسات التحليل الوزني التفاضلي TG-DTA .
Some samples of alumina supporting with sulfate ions and molybdenium were prepared by impregnation method. Supported samples were calcinated at 550°C for 6h. Presence of sulfate ions and molybdenium lead to decreasing of the specific surface area of alumina, and in the ease of molybdenium the decreasing value was higher. The total pore volume was decreased with the pore size was increased. XRD patterns showed that the incorporation of sulfate ions and molybdenium did not affect crystalin structure of alumina. FTIR spectra showed the bonding between sulfate ionsmolybdenium and alumina. The TG-DTA studies showed that the losses mass was decreased when the sulfate ions and molybdenium were incorporated, sulfate ions and molybdenium oxide decomposed at ~700°C and ~800°C respectively .
References used
YANG, X. ; JONTOFT, R. E. ; JONTOFT, F. C. n-Butan isomerization catalyzed by sulfated zirconia nanocrystals supported on silica or γ-alumina. catalysts letters Germany. 2006, 106, 195-203
MIAO, C.; HUE, W.; CHEN, J.; GAO, Z. Studies on So4 -2 promoted mixed oxide superacids . catalysis Letters , USA, 1996, 37, 187-191
(HOLLSTEIN, E. J.; WEI, J. T.; HSU, C. Y. Catalyst for Hydrocarbon Conversion and Conversion Process Utilizing the Same . US patents 4, 918, 041; 4, 956,519 (1990
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Three samples of alumina_zirconia mixed oxid AL2O3_Zr2O4(1;0.25;0.1) mole ratio
based on oxides were prepared by sol-gel precipition method. The system AL2O3_Zr2O4
was obtained by mixing tow gel of alumina and zirconia precipited from aqueous solut
ions
of alumina nitrate and zirconium chlorid using ammonium hydroxide solution as precipited
agent. The system after mixing was allwed to settle for 24 h. The resuling precipitate was
filtered off and washed several times with deionized water and dried at 120°C for 24 h.
The powdered oven-dried hydrous alumina_zirconia was immersed in ammonium sulfate
solution(1) M for 24 h to incorporate sulfate ions. The resulting sample was dried at 120°
C for 24 h, calcined at 550°C for 6 h. The textural properties were determined by terating
of adsorption data of N2 at 77 K, and the results showed the changings in the textural
properties.The TG_DTA analysis showed the thermal stable of the samples in a long rang
of temperature. FTIR spectra showed that the sulfate ions were incorperated in the saples.
يعد الميتانول و الإيتانول من أكثر المحلات شيوعاً، و بما أن درجة غليانها أقل من مئة
درجة مئوية فإنها تتطاير بشكل سريع. و على سبيل المثال، يستعمل الميتانول في تصنيع
الأصبغة و العقاقير و العطور.. و هو شديد السمية، لذلك من الضروري تطوير محسات لكشفه.
أ
ما غاز الأمونيا فهو من ملوثات الهواء و له مصادر كثيرة مثل صناعة الأسمدة و أنظمة
التبريد.. و من هنا أهمية كشفه.
The Xerogel alumina catalyst was prepared by sol-gel
method in non-aqueous milieu, and the aerogel alumina
catalyst was prepared in the same method but it was dried at
by supercritical conditions. These catalysts were characterized
by XRD, BET, a
nd chemical adsorption methods. The
obtained results were compared to show the effect of
preparation process on the structural properties of the alumina.
Besides these results were compared with some oxides
supported on alumina, and the effect of distribution of these
oxides on the properties of alumina was investigated too.
Quinaldine includes shifting hydrogenes which might be involved in
important reactions as the condensation and Mannich reactions.
Quinophtalone has been prepared through the reaction of quinaldine with
phtalyic anhydride in the presence of alumini
um chloride anhydrous
Imines derivatives have been prepared through the reaction of
Quinophtalone with hydroxideamine and phenyl hydrazine and then
diazotion anyhydride has been done to the resulting compounds.
The prepared compounds were characterized by ( H1NMR,IR, MS)
In this work, Rheological and mechanical properties of acrylonitrile –
butadiene – styrene/ corn starch composites (ABS/starch) were studied. The
composites were prepared using a laboratory scale single screw extruder.
Rheological properties were
determined using the single screw extruder, and
apparent shear rate (γ), apparent shear stress (τ), apparent viscosity (η), non-
Newtonian index (n) and flow activation energy at a constant shear rate (Eγ)
and constant shear stress (Eτ) were determined. Mechanical properties in term
of tensile tests were performed using Testometric M350-10KN, stress at break,
strain at break and Young's modulus were determined. Rheological results
showed that the composites are pseudo plastic in behavior, and the apparent
viscosity of the composites increases with increasing starch content above the
additive rule which indicates a partial compatibility in the composite, also it
was found that the flow activation energy of the composite increases with
increasing starch content. Also it was found that the activation energy value at
a constant shear stress is more than that at a constant shear rate. The
mechanical results showed that the strain at break of the composite decreases
sharply by the presence of starch, whereas the young's modulus increases with
increasing starch content.
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