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Effect of a nano-sized natural clinoptilolite modified by the hexadecyltrimethyl ammonium surfactant on cephalexin drug delivery

“…Therefore, the difference in mass loss between NZ and the SMZ, in this region, can be related directly to the surface content of surfactant. These results are similar to those obtained by Gener-Batista [45] and Vujaković et al [46]. Fig.…”

Properties of diclofenac sodium sorption onto natural zeolite modified with cetylpyridinium chloride

“…2c) of the initial zeolitic tuff had an endothermic peak at 113 • C and a shoulder at 213 • C, characteristic of Ca-clinoptilolite from the Zlatokop deposit, Serbia [36]. Usually, because some of water is replaced by the adsorbed organic matter, the size of this peak, in the DTA curves of the organo-clay complexes, is smaller than that in the DTA curve of the untreated clay [34].…”

“…In the second temperature region (230-700 • C), the sharp exothermic peak at 476 • C on the DTA curve of the natural zeolitic tuff demonstrates the oxidation of pyrite which is present in the raw material [36]. In the DTA curves of the organozeolites, an intensive exothermic peak at temperatures >300 • C was observed representing oxidation of the organic matter present at the zeolitic surface.…”

Removal of chromate from wastewater using amine-based-surfactant-modified clinoptilolite

“…The mass loss within the region 20-200°C declined from 8.9 to 6.67 %, which was assigned to the increase in hydrophobicity. The minor peaks between 220 and 250°C are attributed to the oxidation of physisorbed oleylamine, and the broad peak observed at about 325°C represents pyrolysis of the organic substance on clinoptilolite surface (Vujakovic et al 2004). The mass loss due to the surfactant loading on clinoptilolite was calculated to be 4.4 % totally, which is equivalent to 0.163 mmol oleylamine per g clinoptilolite.…”

“…The advancement in uptake capacity ranged between threefold and 20-fold depending on the compositional and textural properties of the raw material and more importantly, on the extent of surfactant loading (Leyva-Ramos et al 2008;Zeng et al 2010;Bajda and Klapyta 2013). An alternative modification route involving primary amine surfactants was proposed by Vujakovic et al (2000Vujakovic et al ( , 2003Vujakovic et al ( , 2004) who pretreated zeolites with strong acidic or basic agents to form a stable surface coverage and to obtain strong sites for anion precipitation. Since the surface precipitation is dominant mechanism for Cr(VI) adsorption, modification of strong acid-treated clinoptilolites with primary aminebased surfactants is an appropriate method to prepare high-performance Cr(VI) adsorbent (Vujakovic et al 2003).…”