“…It can be seen from the data that with mechanical mixing, the sorption capacity of clinoptilolite with dimensions of 1.0–1.5 mm (equivalent diameter of 1.25 mm) is equal to 7.791 mg/g (7.21 × 10 −2 mEq/g) whereas under the action of ultrasonic irradiation, the sorption capacity increases by 28% to 9.989 mg/g (9.25 × 10 −2 mEq/g). Danková et al [34] also reported that the use of ultrasound increases the adsorption capacity of montmorillonite relative to cadmium ions by 40%. Fig.…”
The modification of natural clinoptilolite with silver ions using ultrasound has been investigated in the current work. The modification process was performed using clinoptilolite of different fractions (0–3.0 mm) over the temperature range of 25–55 °C, ultrasonic power range of 8.0–12.5 W and AgNO
3
concentration range of 0.01–0.1 M. The zeolite modification was performed in the presence of sonication and mechanical stirring in separate runs for comparison. Fundamental analysis demonstrated that the use of ultrasound ensures desorption of air from clinoptilolite particles and accelerates the diffusion of Ag
+
ions and subsequent ion exchange. Increasing the particle size of clinoptilolite led to a natural decrease in its sorption capacity. A slight increase in the sorption capacity with an increase in the equivalent particle diameter from 0.081 to 0.35 mm was seen due to changes in the structure of clinoptilolite particles during mechanical grinding. The calculated temperature coefficient of the sorption process of Ag
+
ions as <1.47 means that the modification takes place with dominant control in the intradiffusion region. Increasing the power of ultrasonic irradiation did not provide a monotonous change in the sorption capacity of clinoptilolite. Increasing the concentration of argentum nitrate solution provided an increase in the content of silver ions in clinoptilolite. In general, the advantage of using ultrasonic vibrations to modify the natural clinoptilolite of different fractions with Ag
+
ions was demonstrated in terms of achieving higher sorption capacity, also elucidating the effect of different operating conditions.
“…It can be seen from the data that with mechanical mixing, the sorption capacity of clinoptilolite with dimensions of 1.0–1.5 mm (equivalent diameter of 1.25 mm) is equal to 7.791 mg/g (7.21 × 10 −2 mEq/g) whereas under the action of ultrasonic irradiation, the sorption capacity increases by 28% to 9.989 mg/g (9.25 × 10 −2 mEq/g). Danková et al [34] also reported that the use of ultrasound increases the adsorption capacity of montmorillonite relative to cadmium ions by 40%. Fig.…”
The modification of natural clinoptilolite with silver ions using ultrasound has been investigated in the current work. The modification process was performed using clinoptilolite of different fractions (0–3.0 mm) over the temperature range of 25–55 °C, ultrasonic power range of 8.0–12.5 W and AgNO
3
concentration range of 0.01–0.1 M. The zeolite modification was performed in the presence of sonication and mechanical stirring in separate runs for comparison. Fundamental analysis demonstrated that the use of ultrasound ensures desorption of air from clinoptilolite particles and accelerates the diffusion of Ag
+
ions and subsequent ion exchange. Increasing the particle size of clinoptilolite led to a natural decrease in its sorption capacity. A slight increase in the sorption capacity with an increase in the equivalent particle diameter from 0.081 to 0.35 mm was seen due to changes in the structure of clinoptilolite particles during mechanical grinding. The calculated temperature coefficient of the sorption process of Ag
+
ions as <1.47 means that the modification takes place with dominant control in the intradiffusion region. Increasing the power of ultrasonic irradiation did not provide a monotonous change in the sorption capacity of clinoptilolite. Increasing the concentration of argentum nitrate solution provided an increase in the content of silver ions in clinoptilolite. In general, the advantage of using ultrasonic vibrations to modify the natural clinoptilolite of different fractions with Ag
+
ions was demonstrated in terms of achieving higher sorption capacity, also elucidating the effect of different operating conditions.
“… 34 The bands appeared at ~916 cm −1 can be ascribed to the AlAlOH bending vibrations of MMT. In addition, the small shoulder peaks observed at ~882 cm −1 in the spectrum of Nanomer® I.34MN (Figure 3(b)), and ~ 842 cm −1 in the spectrum of Nanomer® I.31PS (Figure 3(c)) can be attributed to the AlMgOH bending vibrations of MMT 35 . The absorption bands that arised at ~2920 and at ~2850 cm −1 can be ascribed to CH stretching of the CH 3 and CH 2 groups, respectively.…”
Organo‐modified nanoclay incorporated high internal phase emulsions (HIPEs) were successfully used for the preparation of macroporous nanocomposite foams. Due to the aim of obtaining mechanically improved foams, HIPEs were prepared by using a monomer mixture composed of β‐myrcene and ethylene glycol dimethacrylate. Accordingly, two groups of macroporous nanocomposite foams were synthesized depending on the nanoclay type. The morphological analysis demonstrated that the pore openness of the resulting nanocomposites were significantly improved due to the decrease in the average cavity size and increase in the interconnected pore size. In terms of mechanical properties, it was found that filling 1 wt% of nanoclay which is surface modified by hydrogenated tallow lead to a 33% of increment in the compression modulus, as compared to the neat foam. However, loading 5 wt% of nanoclay having octadecylamine and aminopropyltriethoxysilane surface groups caused only 11% of increment in the compression modulus, as compared to the neat foam.
“…The wide band in the area from 950 to 1200 cm -1 are considered to be the "finger print" region for carbohydrates, because it helps in the identification of major chemical groups (-С-О, С-О-С and С-С) in polysaccharides (Urias-Orona et al, 2010). The spectrum showed in Figure 2b is typical for MMT (Dankova et al, 2014). The absorption band at 3627 cm -1 is due to the stretching vibrations of structural OH groups of the MMT.…”
Section: Characterization Of Pec/mmt Compositesmentioning
Long term use of aspirin for prevention of cardiovascular events is limited by its gastrointestinal adverse effects, and, therefore, patients at high risk should receive gastroprotective agents. However, gastroprotective drugs also have a few adverse effects that require searching for safe and effective alternatives. The composites combining the swelling properties of clays and the biological activity of polysaccharides seem to be promising candidates for gastrointestinal protection. This study aimed to characterize pectin/montmorillonite composites and evaluate their protective effect on the gastrointestinal tract of rats taking aspirin over a long period. A series of composites based on montmorillonite (ММТ) and low esterified pectin (Pec) was synthesized using the adsorption-precipitation method. The polysaccharide to clay weight ratios were 1:19, 1:9, and 1:4. The composites were characterized using Thermogravimetric Analysis (TGA), Infrared Spectroscopy (IR), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). Pectin was completely fixed on MMT, and the polysaccharide content in the composites was approximately 5, 10, and 20 wt%, respectively. The shifting of the absorption band of the C=O group of the pectin indicated the interaction of the polysaccharide with the clay, confirming effective immobilization of Pec on MMT. Modification with pectin changed the morphology and structure of the MMT due to the surface coating and intercalation into the interlayer space. The composites swelled in acidified water (pH = 2.0), and their swelling ability was higher to compare with unmodified MMT. The sorption capacity of Pec/MMT composites towards acetylsalicylic acid (ASA) was decreased from 6.8 to 1.0 mg g-1 with increasing of pectin content from 5 to 20 wt%. The hybrid composites promoted the protection of the gastrointestinal tract of rats, which were administered ASA with Pec/MMTs for 16 days. Protective properties of the Pec/MMT have been improved with increasing pectin content from 5 to 20 wt%.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
