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Synthesis, characterization and catalytic properties of SAPO-11 molecular sieve synthesized in hydrothermal media using di-isopropylamine as template

Chellappa T., Costa M. J. F., Nascimento W. A., Ferreira De Lima L., Bassan I. A., Tavares M., Fernandes V. J., Menezes A., Guilherme Meira L., Telesforo Nóbrega De Medeiros J., Maribondo Do Nascimento R.

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2014

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Vol. 62, nr 3

481--488

EN

A microporous SAPO-11 Molecular sieve was successfully synthesized by the hydrothermal method, using a single agent, as an organic template: di-isopropylamine (DIPA). The obtained solid was calcined at 550◦C for three hours, after which the flow of nitrogen was exchanged for that of synthetic air and submitted for another ten hours of calcination, so as to remove the single agent: di-isopropylamine, which after the removal of the template could be observed by the high crystallization of the sample. Furthermore, the molecular sieve was characterized by XRD, SEM, TG-DTG and N2 adsorption desorption (BET analysis). The obtained catalyst proved to have a high potential catalytic activity and selectivity, through the obtained characterization results, exhibiting good hydrothermal stability. The catalytic performance of SAPO-11 was tested by the deactivation/regenerability of the coked sample, furthered by cracking of n-hexane reaction and high olefins selectivity was obtained.

2

Znaczenie mikroporowatych materiałów metaloorganicznych (MOF ) dla potrzeb magazynowania wodoru

Czub J., Gondek Ł, Figiel H.

Wiadomości Chemiczne

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2012

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[Z] 66, 3-4

227-247

EN

Currently, the metal-organic frameworks (MOF s) are considered among the most promising materials for hydrogen storage. In this paper, the properties of MOF s that are particularly important for application purposes are presented. Examples include simplicity of their syntheses on an industrial scale, low synthesis costs, high thermal stability and durability, an excellent repeatability and very low degree of degradation during cyclic hydrogen loading and recovery. On the other hand, the potential use of MOF s as hydrogen reservoirs is to some extent limited due to the fact that the low temperatures of 77 K are required for effective adsorption of hydrogen in the microporous structures of MOF s. Nowadays, the research on MOF s is carried in two directions. In particular, there are intensive studies on increasing of the concentration of hydrogen adsorbed at low temperatures in order to determine the limiting value for which maintaining the reservoir at the temperature of liquid hydrogen would be economically viable. It seems that the limiting concentration is being currently reached. The second direction of research is to increase the limiting value of temperature at which the concentration of adsorbed hydrogen is acceptable.

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Kinetics of nanocrystalline iron nitriding

Arabczyk W., Zamłynny J., Moszyński D.

Polish Journal of Chemical Technology

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2010

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Vol. 12, nr 1

38-43

EN

Nitriding of nanocrystalline iron was studied under the atmosphere of pure ammonia and in the mixtures of ammonia - hydrogen - nitrogen at temperatures between 350°C and 500°C using thermogravimetry and x-ray diffraction. Three stages of nitriding were observed and have been ascribed to the following schematic reactions: (1) α-Fe → γ-Fe4N, (2) γ- Fe4N → ε - Fe3N and (3) ε - Fe3N → ε - Fe2N. The products of these reactions appeared in the nitrided nanocrystalline iron not sequentially but co-existed at certain reaction ranges. The dependence of a reaction rate for each nitriding stage on partial pressure of ammonia is linear. Moreover, a minimal ammonia partial pressure is required to initiate the nitriding at each stage.

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Medyczne zastosowania sit molekularnych

Długopolska K., Ruman T., Pogocki D., Danilczuk M.

Wiadomości Chemiczne

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2009

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[Z] 63, 11-12

1073-1088

EN

Molecular sieves are porous, crystalline materials usually synthetic or natural zeolites, that contain well-defined pores of precise and uniform size. The term zeolite originally described a group of natural crystalline aluminosilicates, however nowadays the term covers many different materials such as aluminophosphates or gallium-silicalites. During the last few decades microporous and mesoporous materials have been considered for medical use due to biological properties and stability in biological environment [1-4]. Zeolites have been investigated as drug carriers, dietetic supplements, antimicrobial agents or as adjuvants in anticancer therapy [3–9]. Unique "magnetic" zeolite was obtained by Shan et al. Zeolite nanocrystals were in situ combined with superparamagnetic magnetite (Fe3O4) nanoparticles in the hydrothermal synthesis procedure. An high amount of enzymes adsorption and a good biocatalytic performance is shown by those newly formed magnetite/zeolite composite nanoparticles [15]. Zeolite of the CuX type has been used as a support for a antitumoral drug-cyclophosphamide. The in vivo tests show that the intensity of the antitumoral effects of the CuX zeolitecyclophosphamide system is similar in comparison to the one achieved by cyclophosphamide alone [21]. Ion-exchanged zeolites have also been used as a novel approach to storage and delivery of nitric oxide (NO) [16]. Zeolite surface coatings offer antimicrobial protection through the controlled release of antimicrobial agent and can be applied to different types of surfaces or incorporated in many types of polymers [17, 18]. Rivera group prove that both zeolitic materials and drugs could be simultaneously administrated to a patient without any loss of an individual pharmaceutical effect of each product [22]. Zeolite matrix has been also used to stabilize erythromycin solutions. An existing commercial product based on diisopropylsebacate/ethanol solution of 4% erythromycin and zinc acetate (ZinerytŽ, Yamanouchi Pharma) has been compared to analogical system where active compounds are loaded into porous material [26]. Natural clinoptilolite is the main and active component of the antidiarrheal drug acting as adsorbent of bile acids, Aflatoxine B and Glucose [64]. Recent studies show that this material can also be utilized as an adjuvant in anticancer therapy [10–13, 46–47]. The new antacid drug NeutacidŽ is based on the neutralizing capacity of the purified natural zeolite – clinoptilolite from the Tasajera deposit (Cuba) for therapy of patients suffering from hyperacidity produced by gastric dyspepsia and gastric-duodenal ulcer [50]. Mesoporous material MCM-41, due to the pore size tunability and functionalization possibilities, can especially encapsulate a variety of different drug molecules and release them in controlled ways [27, 28, 30–36]. Zeolites containing silver ions are used as antimicrobial agents [53–57]. Zeolites are the main ingredient of commercially available anti-bleed agents [67].

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Fosforany warstwowe

Sarbak Z.

LAB Laboratoria, Aparatura, Badania

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2007

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R. 12, nr 6

26-34

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Pilarowane materiały ilaste

Sarbak Z.

LAB Laboratoria, Aparatura, Badania

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2005

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R. 10, nr 6

16-22

PL

Pilarowane materiały ilaste stanowią nowy rodzaj materiałów porowatych zaprojektowanych dla wielu specyficznych celów, z których jednym jest otrzymywanie materiałów wykazujących właściwości sitowo-molekularne, co znajduje szerokie wykorzystanie w adsorpcji i katalizie. Charakteryzują się one wysoką aktywnością i selektywnością w wielu reakcjach katalitycznych stosowanych w przemyśle. Do otrzymywania materiałów pilarowanych wykorzystuje się tanie i powszechnie dostępne minerały ilaste, które poddaje się tylko odpowiedniej, prostej modyfikacji, przez co unika się żmudnych i skomplikowanych syntez chemicznych.

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Naturalne krzemiany i glinokrzemiany

Sarbak Z.

LAB Laboratoria, Aparatura, Badania

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2005

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R. 10, nr 2

16-21

PL

Ogromne znaczenie naturalnych krzemianówi glinokrzemianów jako surowca w wielu gałęziach przemysłowych przyczyniło się do stosunkowo dobrego poznania ich właściwości fizykochemicznych. Zainteresowanie tymi materiałami związane było początkowo z ich zastosowaniem jako surowca do wytwarzania materiałów budowlanych i ceramicznych. Stwierdzono ponadto, że wykazują one specyficzne właściwości chłonne i potrafią przetwarzać jedne związki chemiczne w inne. Cechy te predestynują je do szerszego wykorzystania w procesach adsorpcji oraz w wielu procesach katalitycznych jako katalizatorów lub ich nośników. Związane jest to z ich specyficzną strukturą porowatą oraz właściwościami chemicznymi powierzchni.

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Materiały mikro- i nanoporowate

Sarbak Z.

LAB Laboratoria, Aparatura, Badania

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2004

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R. 9, nr 6

6-12