Ion-exchange of transition metal ions into montmorillonite was investigated using two different ion-exchange procedures. Performing ion-exchange from aqueous solution of the respective metal ion leads to material possessing measurable BrØnsted acidity, while the solid-state exchange materials show predominantly Lewis acidity.
Thermal behaviour of pure LiN3, NaN3, CsN3 and their mixture with the respective LiY-FAU, NaY-FAU, CsY-FAU zeolite was investigated by means of thermogravimetry and IR spectroscopy. Thermodesorption of CO2 was applied to compare the basicity of the alkali ionexchanged Y zeolites. Two of the investigated systems, the NaN3/NaY-FAU and the CsN3/CsY-FAU gave single, well defined and reproducible azide decomposition features rendering these samples to apply as catalyst precursors for preparation of zeolite with basic character.
Authors:Judit Varga, Á. Fudala, J. Halász and I. Kiricsi
The solid-state ion-exchange procedures of zeolites with Cu2+, Ni2+, Fe2+ and Co2+ salts can be resulted in prosperous catalysts for NO decomposition. Reactions taking place in solid-state between four transition metal cholirides and H-ZS-5 zeolite were investigated by means of a derivatograph. The results showed that irreversible consumption of surface -OH groups occurred with simultaneous bonding of the transition metal in the zeolite channel structure.
Authors:A. Béres, I. Pálinkó, Á. Fudala, I. Kiricsi, Y. Kiyozumi, F. Mizukami and J. Nagy
Mg-Al L(ayered) D(ouble) H(ydroxide) was prepared and its thermal behaviour was characterized by thermoanalytical methods
(TG, DTG, DTA), 27Al M(agic) A(ngle) S(pinning) NMR spectroscopy, X-ray diffractometry (XRD) and S(canning) E(lectron) M(icroscopy). Heat treatment
destroyed the layered structure, which could only be partially reconstituted by rehydration. On calcination mixed oxide with
the predominance of basic sites were formed. Pillaring the LDH with Fe(CN)64- anions was also performed. The material was characterized by XRD and BET measurements. Heat stability of the pillared substance
was investigated, too. Pillaring proved to be successful, however, decreased heat resistance was found in the intercalated
material relative to the guest LDH.
Authors:M Tokodi, E Csábi, Á Kiricsi, E Kollár, AH Molnár, L Rovó and Z Bella
This study aims to compare the impact of active allergic rhinitis on physical and cognitive abilities of trained allergic athletes to untrained allergic patients.
Cognitive, respiratory, and fitness functions were assessed before and after allergen exposure. Participants in both groups were provoked intranasally with ragweed allergen.
The group of athletes revealed significantly higher average values in peak inspiratory flow and fitness index before and after provocation. In neuropsychological assessments, athletes performed significantly better after allergen provocation in complex working memory capacity. Due to single acute allergen exposure, the size of the nasal cavity and nasal inspiratory peak flow significantly decreased in both groups. The physical performance of both groups did not change after provocation. Executive functions and complex working memory capacity of athletes significantly improved resulting from provocation.
A single-shot allergen in high dose might cause an increase in mental concentration, which was more pronounced in the group of athletes. This study indicates that acute exposure to allergen cannot affect the physical performance and may result in increased mental focus in patients with allergy notwithstanding the declining respiratory functions.
Authors:A. Szabo, A. Fonseca, L. P. Biro, Z. Konya, I. Kiricsi, A. Volodin, C. Van Hasendonck and J. B.Nagy
Some recent results on
the synthesis of coiled carbon nanotubes (CNTs) are summarized. Several
supported catalysts can lead to the formation of coiled CNTs. Interestingly,
certain domains of the coil pitch and coil diameter are favoured, and two
“stability islands”are found in the 3D representation of the number of coiled
CNTs as a function of both coil pitch and coil diameter. It is emphasized that
these nanotubes are formed either by introducing pairs of five-membered ring -
seven-membered ring or by forming haeckelite structures. The coiled CNTs could
be used in nanocomposite reinforcement as well as special sensors based on
their remarkable mechanical and electrical properties.