45 research outputs found

    Gamma radiation effects on vitamins, antioxidant, internal and molecular structure of Purslane seeds

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    Purslane contains the highest amount of omega-3 fatty acids, antioxidants, and has better nutritional quality. Gamma irradiation is harmless and dependable method for refining the shelf life and nutritional quality of the stored seeds. The aim of this research is to study the influence of irradiation by gamma on structure, ascorbic acid and phenolic content of Purslane seeds. The results show that, ascorbic acid, phenolic content, carbohydrate and protein content in Purslane seeds decreased after exposed by gamma rays. Super oxidase dismutase, fat and fiber content in Purslane seeds increased after exposed by gamma radiation. The shape, size, interconnection and arrangement of molecules in/or around benzene ring in Purslane cells changed after exposure to gamma radiation

    SYNTHESIS AND CHARACTERIZATION OF AMINO-BASED CARBOXYMETHYL CHITOSAN AND ITS ADSORPTION FEATURES TOWARDS CU (II) AND ZN (II) IONS

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    This work was supported by the Program 211 of the Government of the Russian Federation, RFBR grants 17-03-00641 and 18-29-12129mk, the State Task from the Ministry of the Education and Science of the Russian Federation

    Grafting of (3-chloropropyl)-trimethoxy silane on halloysite nanotubes surface

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    Modified halloysite nanotubes (HNTs-Cl) were synthesized by a coupling reaction with (3-chloropropyl) trimethoxysilane (CPTMS). The incorporation of chloro-silane onto HNTs surface creates HNTs-Cl, which has great chemical activity and is considered a good candidate as an active site that reacts with other active molecules in order to create new materials with great applications in chemical engineering and nanotechnology. The value of this work lies in the fact that improving the degree of grafting of chloro-silane onto the HNT’s surface has been accomplished by incorporation of HNTs with CPTMS under different experimental conditions. Many parameters, such as the dispersing media, the molar ratio of HNTs/CPTMS/H2O, refluxing time, and the type of catalyst were studied. The greatest degree of grafting was accomplished by using toluene as a medium for the grafting process, with a molar ratio of HNTs/CPTMS/H2O of 1:1:3, and a refluxing time of 4 h. The addition of 7.169 mmol of triethylamine (Et3N) and 25.97 mmol of ammonium hydroxide (NH4OH) led to an increase in the degree of grafting of CPTMS onto the HNT’s surface

    ADSORPTION OF COPPER AND ZINC ON HALLOYSITE NANOTUBES MODIFIED BY POLYETHYLENE IMINE: KINETIC AND THERMODYNAMIC STUDIES

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    This work was supported by the Program 211 of the Government of the Russian Federation, RFBR grants 17-03-00641 and 18-29- 12129mk, the State Task from the Ministry of the Education and Science of the Russian Federation

    Chitosan Functionalized with Carboxyl Groups as a Recyclable Biomaterial for the Adsorption of Cu (II) and Zn (II) Ions in Aqueous Media

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    The modification of chitosan represents a challenging task in obtaining biopolymeric materials with enhanced removal capacity for heavy metals. In the present work, the adsorption characteristics of chitosan modified with carboxyl groups (CTS-CAA) towards copper (II) and zinc (II) ions have been tested. The efficacy of the synthesis of CTS-CAA has been evaluated by studying various properties of the modified chitosan. Specifically, the functionalized chitosan has been characterized by using several techniques, including thermal analyses (differential scanning calorimetry and thermogravimetry), spectroscopies (FT-IR, XRD), elemental analysis, and scanning electron microscopy. The kinetics and the adsorption isotherms of CTS-CAA towards both Cu (II) and Zn (II) have been determined in the aqueous solvent under variable pH. The obtained results have been analyzed by using different adsorption models. In addition, the experiments have been conducted at variable temperatures to explore the thermodynamics of the adsorption process. The regeneration of CTS-CAA has been investigated by studying the desorption process using different eluents. This paper reports an efficient protocol to synthesize chitosan-based material perspective as regenerative adsorbents for heavy metals. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.The authors express their gratitude to Princess Nourah bint Abdulrahman University Researchers Supporting Project number (PNURSP2022R13), Princess Nourah bint Abdulrahman University, Riyadh, Saudi Arabia. The work was supported by the Russian Foundation for Basic Research (RFBR) grant 18-29-12129mk. The researcher A.M. Abu El-Soad is funded by a scholarship under the Joint Executive program between the Arab Republic of Egypt and Russian Federation

    Grafting of (3-chloropropyl)-trimethoxy silane on halloysite nanotubes surface

    Full text link
    Modified halloysite nanotubes (HNTs-Cl) were synthesized by a coupling reaction with (3-chloropropyl) trimethoxysilane (CPTMS). The incorporation of chloro-silane onto HNTs surface creates HNTs-Cl, which has great chemical activity and is considered a good candidate as an active site that reacts with other active molecules in order to create new materials with great applications in chemical engineering and nanotechnology. The value of this work lies in the fact that improving the degree of grafting of chloro-silane onto the HNT’s surface has been accomplished by incorporation of HNTs with CPTMS under different experimental conditions. Many parameters, such as the dispersing media, the molar ratio of HNTs/CPTMS/H2O, refluxing time, and the type of catalyst were studied. The greatest degree of grafting was accomplished by using toluene as a medium for the grafting process, with a molar ratio of HNTs/CPTMS/H2O of 1:1:3, and a refluxing time of 4 h. The addition of 7.169 mmol of triethylamine (Et3N) and 25.97 mmol of ammonium hydroxide (NH4OH) led to an increase in the degree of grafting of CPTMS onto the HNT’s surface. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This research was funded by Program 211 of the Government of the Russian Federation No. 02.A03.21.0006, RFBR grants 17-03-00641 and 18-29-12129 mk, the State Task from the Ministry of the Education and Science of the Russian Federation No. 4.9514.2017/8.9
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