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Fragrance Finishing on Textile Substrate for Odour Control
Published in G. Thilagavathi, R. Rathinamoorthy, Odour in Textiles, 2022
Thillaipandian Hemamalini, Venkateshwarapuram Rengaswami Giri Dev
Zeolite is an aluminosilicate mineral found in abundance and used for various technical applications, such as medicine, construction, agriculture, environmental protection, gas, and petrochemical treatment. The polymer offers a microporous structure with the crystalline component of clinoptilolite, which forms a tetrahedron structure with other impurities, montmorillonite and mordenite, which acts as an effective adsorbent for absorbing volatile chemical compounds from the environment. The polymer was treated with surface mercerized cotton and alkali-treated polyester fabric in the form of nanoparticles to study the efficiency of coated fabric for UV protection after treating with fluorescence whitening agents, and antimicrobial activity after treating with an antibiotic, namely azithromycin. It was reported that cotton fabric offered higher UV resistance compared to polyester fabric and also promoted wound healing activity by inhibiting the growth of microorganisms in the in-vitro condition (Grancarić, Tarbuk, and Kovaček 2009).
Electrochemistry of Aluminosilicates
Published in Antonio Doménech-Carbó, Electrochemistry of Porous Materials, 2021
Silicates are an important group of substances that have a skeleton based on tetrahedral SiO4 units tailored to adopt a wide variety of structures. Their related aluminosilicates are those where a certain number of silicon atoms have been isomorphically substituted by aluminum ones. As a result, a defect of positive charge is produced in the lattice. Compensation of this excess of negative charge requires the formation of silanol groups and/or the attachment of cationic species to the aluminosilicate framework. SiO4 and AlO4 tetrahedral units act as a building unit in constructing a wide variety of structures, from porous (zeolites, sepiolite) to laminar silicates and aluminosilicates (montmorillonite, kaolinite). Since the preparation [1] of periodic mesoporous silica (MCM-41), a variety of silica-based mesoporous materials have been synthesized with a variable degree of order, stability, and Al/Si ratios. An important group of materials is constituted by different types of porous silica [2].
Zeolite
Published in Mihai V. Putz, New Frontiers in Nanochemistry, 2020
Adriana Urdă, Ioan-Cezar Marcu
The first synthesis method, used by R. M. Milton in the 1940s, was the hydrothermal crystallization of alkali aluminosilicate gels at low pressures and temperatures (ca. 100°C) and high pH (10-14), using cation templating (Flanigen, 2001). The alkali cation is used for “templating” and stabilizing the sub-units in the zeolite structure during synthesis. The use of quaternary ammonium cations in the 1960’s made possible the discovery of intermediate and high silica zeolites, with the crystallization step occurring at higher temperatures (up to ca. 200°C). Later, Fˉ ion used as mineralizer and template allowed the synthesis to be carried out in acidic pH, with the zeolite product having larger and more defect-free crystals, and even new structures.
Design of flexible pavement thickness using stabilized high plastic soil by means of fly ash-based geopolymer
Published in International Journal of Pavement Engineering, 2022
Sagar D. Turkane, Sandeep K. Chouksey
In this context, the utilisation of low energy-intensive stabilisers such as cement kiln dust, calcium carbide residue, granulated blast furnace slag, fly ash, and geopolymeric binder in soil stabilisation has been studied by various researchers (Ghosh et al.2016, Phummiphan et al.2016, 2018, Leong et al.2018, Murmu et al.2018, 2019) in recent years. Geopolymer is an inorganic aluminosilicate material formed from the polycondensation of silica and alumina (Davidovits 1991, Zhang et al.2013). Davidovits 1991 proposed the general chemical structure in 1991 , where M is the alkaline element, indicate the presence of a bond, z is 1,2 or 3 and n is the degree of polymerisation. In which tetrahedral silica and alumina are linked to each other by sharing all the oxygen atoms by forming a 3D network of aluminosilicate structures.
Removal of fluoride ions (F−) from aqueous solutions using modified Turkish zeolite with quaternary ammonium
Published in Environmental Technology, 2021
Hajer Aloulou, Ali Ghorbel, Wala Aloulou, Raja Ben Amar, Sabeur Khemakhem
Among the natural adsorbents, zeolites occupy a major position due to their good sorption properties, their abundance and low cost. Zeolites can be used in various applications regarding its specific pore sizes and large surface areas. Zeolite is microporous, aluminosilicate minerals also commonly used as commercial adsorbents. The natural zeolite is based on the structure of three-dimensional network of an aluminum and silicon tetrahedral linked by shared oxygen atoms. Aluminum has a positive charge lower than that of silicon, as a result, the frame generally has a net negative charge which is balanced by exchangeable cation (K+, Na+, Mg2+ and Ca2+). Accordingly, this negative surface charge results in natural zeolite having excellent affinity for cationic ions [29,30].
Study on the effect of seed particle size toward the formation of NaX zeolite membranes via vacuum-assisted seeding technique
Published in Journal of Asian Ceramic Societies, 2021
Liyana Salwa Mohd Nazir, Yin Fong Yeong, Thiam Leng Chew
Over the past decades, zeolite membranes have shown great potential in various separation applications compared to the other types of inorganic membranes. Zeolite is a crystalline, aluminosilicate material with well-defined framework and pore structure. The characteristics of zeolites, such as molecular sieving ability, catalytic and selective sorption properties, thermal and chemical stabilities, have made them potential candidate in various applications including gas separation, pervaporation, solvent dehydration, membrane reactors, coating materials, catalytic micro reactors, gas sensors, and fuel cells [1–7]. Zeolite membrane was firstly prepared by Suzuki in 1987, where a continuous zeolite layer was synthesized on the porous support [8]. In 1998, Mitsui Engineering and Shipbuilding Co. Ltd in Japan was the first company to apply NaA zeolite membrane for pervaporation dehydration in industrial-scale separation plant [9]. Subsequently, the applications of zeolite membranes have been extensively explored and reported in the literature [4,5,10–14].