Effect of H-ZSM-5 zeolite content on the intrinsic kinetics of the methanol dehydration to dimethyl ether over H-ZSM-5/Al2O3 molded catalyst

A series of H-ZSM-5/Al2O3 molded catalysts with various zeolite/alumina ratios has been prepared and their catalytic activity in the methanol dehydration to dimethyl ether has been studied. Based on Langmuir-Hinshelwood...

TENSILE AND STRETCH OF PAPER FILLED WITH BACTERICIDAL ZEOLITES

The purpose of present work was to study tensile and stretch of paper prepared with the use of bactericide zeolite fillers containing up to 130 mg/g of silver, 72 mg/g of copper, and 58 mg/g of zinc, prepared by ion exchange reactions using heulandite-clinoptilolite from the Rkoni plot of the Tedzami deposit, Eastern Georgia. Filled papers with zeolite content up to 4 g/m2 and bactericidal activity confirmed by the colony forming unit assay were manufactured on the production lines of the GPM enterprise (Tbilisi, Georgia). The measured tensile strength and percentage elongation of filled paper depend on the nature of the filler and its metal content; the introduction of pure zeolite filler reduces the tensile and stretch of the paper, but fillers containing silver and copper increase the tensile strength. Accelerated aging results in lower tensile and stretch, but zeolite fillers generally make the paper more resistant to aging.

Hydrothermal synthesis and characterisation of zeolites from metakaolin and water glass

Zeolites were synthetised from two types of metakaolin mixed with water glass and in some samples with water. The mixtures were autoclaved for 24 hours at 130°C. Autoclaved samples were ground to analytical fineness and tested by X-ray diffraction and differential thermal analysis. Polished samples embedded in epoxy resin were studied using of electron microprobe including BSE imaging and WDX analysis of chemical composition of zeolites. Samples with the highest zeolite content were studied by SEM. The obtained results showed that the dominant synthetised zeolite in autoclaved samples is mineral chemically close to chabazite, less phillipsite. Zeolite Na-P1, gmelinite and boggsite were also identified by XRD analyses. The total content of zeolites is up to 29 wt. % in the sample prepared from a mixture containing metakaolin MK1/sodium water glass/water in weight ratio 1.5/2.5/1. The Si/Al of synthetised zeolites varies between 2.1 and 3.2.

Effects of Processing Conditions and Plasticizing-Reinforcing Modification on the Crystallization and Physical Properties of PLA Films

The polylactic acid (PLA) resin Ingeo 4032D was selected as the research object. Epoxy soybean oil (ESO) and zeolite (3A molecular sieve) were used as plasticizer and reinforcing filler, respectively, for PLA blend modification. The mixture was granulated in an extruder and then blown to obtain films under different conditions to determine the optimum processing temperatures and screw rotation. Then, the thermal behaviour, crystallinity, optical transparency, micro phase structure and physical properties of the film were investigated. The results showed that with increasing zeolite content, the crystallization behaviour of PLA changed, and the haze of the film increased from 5% to 40% compared to the pure PLA film. Zeolite and ESO dispersed in the PLA matrix played a role in toughening and strengthening. The PLA/8 wt% zeolite/3 wt% ESO film had the highest longitudinal tensile strength at 77 MPa. The PLA/2 wt% zeolite/3 wt% ESO film had the highest longitudinal elongation at 13%. The physical properties depended heavily on the dispersion of zeolite and ESO in the matrix.

A Laboratory Study of Warm Mix Asphalt with Synthetic Zeolite

Warm mix asphalt (WMA) is a recent technology used to reduce working temperatures without affecting the property of pavement. warm mix asphalt technology is a find out the optimum temperature of asphalt mixture. A number of WMA processes have been developed in recent days. One of the processes is the use of synthetic zeolite as an additive. A number or try in the laboratory to develop warm mix asphalt and using synthetic zeolite as an additive at a specified mixing and optimum temperature which were obtained after a number of trials. Warm mixing with additive is becoming popular because of mixing at a lower temperature which reduces the fuel usage and emission of hazardous gases consequently decreases the mixing as well as compaction temperature of the mix. Reduction of 20º C to 40º C has documented, such reduction has the obvious benefits of cutting fuel consumption and decreasing the production of greenhouse gases. Also, there will improvement in the performance of the pavement. In the present study, The mix asphalt with aggregate gradation as per MORTH specifications was made with varying binder contents (5%,6% and7%). The zeolite content was 0.3% by weight of aggregate. Stone dust and VG 30-grade Asphalt were used as a binder for the mixes. and the help of laboratory tests to find the physical properties of WMA with synthetic zeolite at optimum temperature. These additives are zeolites, that is, minerals of the aluminosilicate group, the crystalline structure of which contains water bound in a specific way. Its release, at mixed asphalt production temperatures, causes asphalt foaming. It is currently known that zeolites can be used in WMA, including natural and synthetic zeolites obtained using chemical reagents and waste. This review presents the results of studies of WMA technology, including the effects of zeolite addition on asphalt properties and mixes asphalt, as well as related environmental, economic, and technological benefits.

A Green Composite Based on Gelatin/Agarose/Zeolite as a Potential Scaffold for Tissue Engineering Applications

Designing a novel platform capable of providing a proper tissue regeneration environment is a key factor in tissue engineering. Herein, a green composite based on gelatin/agarose/zeolite with pomegranate peel extract was fabricated as an innovative platform for tissue engineering. Gelatin/agarose was loaded with pomegranate peel extract-loaded zeolite to evaluate its swelling behavior, porosity, release rate, and cell viability performance. The composite characteristics were evaluated using XRD and DSC. The hydrogel performance can be adjusted for the desired aim by zeolite content manipulation, such as controlled release. It was shown that the green nanocomposite exhibited proper cellular activity along with a controlled release rate. Moreover, the hydrogel composite’s swelling ratio was decreased by adding zeolite. This study suggested a fully natural composite as a potential biomaterial for tissue engineering, which opens new ways to design versatile hydrogels for the regeneration of damaged tissues. The hydrogel performance can be adjusted specifically by zeolite content manipulation for controlled release.

Thermophysical Properties of Kaolin–Zeolite Blends up to 1100 °C

In this study, the thermophysical properties such as the thermal expansion, thermal diffusivity and conductivity, and specific heat capacity of ceramic samples made from kaolin and natural zeolite are investigated up to 1100 °C. The samples were prepared from Sedlec kaolin (Czech Republic) and natural zeolite (Nižný Hrabovec, Slovakia). Kaolin was partially replaced with a natural zeolite in the amounts of 10, 20, 30, 40, and 50 mass%. The measurements were performed on cylindrical samples using thermogravimetric analysis, a horizontal pushrod dilatometer, and laser flash apparatus. The results show that zeolite in the samples decreases the values of all studied properties (except thermal expansion), which is positive for bulk density, porosity, thermal diffusivity, and conductivity. It has a negative effect for thermal expansion because shrinkage increases with the zeolite content. Therefore, the optimal amount of zeolite in the sample (according to the studied properties) is 30 mass%.

Removal of anionic dye Congo red from aqueous environment using polyvinyl alcohol/sodium alginate/ZSM-5 zeolite membrane

In this study, a novel PVA/SA/ZSM-5 zeolite membrane with good regeneration capacity was successfully prepared by solvent casting technique. The properties of the membranes were assessed by employing different characterization techniques such as X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), optical microscopy (OP), thermogravimetric analysis (TGA), contact angle and universal testing machine (UTM). XRD, TGA and UTM results revealed that the crystallinity and thermo-mechanical performance of the membrane could be tuned with zeolite content. The successful incorporation of zeolite into the polymer matrix was confirmed by FT-IR, SEM and OP analysis. The adsorption ability of the as-prepared membrane was evaluated with a model anionic dye, Congo red. Adsorption studies show that the removal efficiency of the membrane could be tuned by varying zeolite content, initial concentration of dye, contact time, pH and temperature. Maximum dye adsorption (5.33 mg/g) was observed for 2.5 wt% zeolite loaded membrane, at an initial dye concentration of 10 ppm, pH 3 and temperature 30 °C. The antibacterial efficiency of the membrane against gram-positive (Staphylococcus aureus) and gram-negative bacteria (Escherichia coli) was also reported. The results show that membrane inhibits the growth of both gram-positive and gram-negative bacteria. The adsorption isotherm was studied using two models: Langmuir and Freundlich isotherm. The results show that the experimental data fitted well with Freundlich isotherm with a high correlation coefficient (R2 = 0.998). Meanwhile, the kinetic studies demonstrate that pseudo-second-order (R2 = 0.999) model describe the adsorption of Congo red onto PVA/SA/ZSM-5 zeolite membrane better than pseudo-first-order (R2 = 0.972) and intra particle diffusion model (R2 = 0.91). The experimental studies thus suggest that PVA/SA/ZSM-5 zeolite could be a promising candidate for the removal of Congo red from aqueous solution.