Incorporation Of Zeolites Research Articles

Removal of Remazol Red Dyes Using Zeolites-Loaded Nanofibre Coated on Fabric Substrates

Nanofibre-based membranes have shown great potential for removing textile wastewater due to their high porosity and surface area. However, nanofibre membranes exhibit lower dye removal efficiency. Hence, this study aims to improve the dye removal performance of nanofibre membranes by incorporating zeolites. The research involved fabricating composite membranes by electrospinning polyvinyl alcohol (PVA) nanofibres incorporated with zeolites. Mechanical strength was enhanced by placing the PVA/zeolite nanofibre membrane between fusible nonwoven interfacing and woven polyester fabric, followed by heat treatment. Morphological analysis revealed the uniform dispersion of zeolite particles within the PVA nanofibres. EDX analysis confirmed the successful incorporation of zeolites into the fibres. Among all membrane samples, the PZ-0.75 membrane exhibited the highest pure water flux (PWF) with approximately 1358.57 L·m−2·min−1 for distilled water and 499.85 L·m−2·min−1 for batik wastewater. Turbidity of batik wastewater increased proportionally with zeolite concentration, with removal rates of 84.79%, 78.8%, 76.96%, and 74.19% for PZ-0.75, PZ-0.5, PZ-0.25, and PVA membranes, respectively. Furthermore, the UV/Vis spectrophotometer demonstrated that dye removal efficiency increased from 2.22% to 8.89% as the zeolite concentration increased from 0% to 0.75%. In addition, the PZ-0.75 membrane effectively removed RR dye at a concentration of 1 mg/L, with an optimal contact time of approximately 60 min. The adsorption mechanism of the PZ-0.75 membrane aligns with the Freundlich model, with an R2 value of 0.983. Overall, this study demonstrates the efficiency of zeolite in the fabric substrates to improve the filtration and adsorption properties for wastewater treatment, particularly in textile industries.

Hydrogel nanocomposite based on alginate/zeolite for burn wound healing: In vitro and in vivo study.

The main objective of the current assay was to evaluate the antibacterial and regenerative effects of hydrogel nanocomposite containing pure natural zeolite (clinoptilolite) integrated with alginate (Alg) as wound healing/dressing biomaterials. The zeolites were size excluded, characterized by SEM, DLS, XRD, FTIR, and XRF, and then integrated into Alg hydrogel followed by calcium chloride crosslinking. The Alg and alginate zeolite (Alg/Zeo) hydrogel was characterized by swelling and weight loss tests, also the antibacterial, hemocompatibility, and cell viability tests were performed. In animal studies, the burn wound was induced on the back of rats and treated with the following groups: control, Alg hydrogel, and Alg/Zeo hydrogel. The results showed that the hydrodynamic diameter of zeolites was 367 ± 0.2 nm. Zeolites did not show any significant antibacterial effect, however, the hydrogel nanocomposite containing zeolite had proper swelling as well as hemocompatibility and no cytotoxicity was observed. Following the creation of a third-degree burn wound on the back of rats, the results indicated that the Alg hydrogel and Alg/Zeo nanocomposite accelerated the wound healing process compared with the control group. Re-epithelialization, granulation tissue thickness, collagenization, inflammatory cell recruitment, and angiogenesis level were not significantly different between Alg and Alg/Zeo nanocomposite. These findings revealed that although the incorporation of zeolites did not induce a significant beneficial effect in comparison with Alg hydrogel, using zeolite capacity in hydrogel for loading the antibiotics or other effective compounds can be considered a promising wound dressing.

Pervaporation Zeolite-Based Composite Membranes for Solvent Separations.

Thanks to their well-defined molecular sieving and stability, zeolites have been proposed in selective membrane separations, such as gas separation and pervaporation. For instance, the incorporation of zeolites into polymer phases to generate composite (or mixed matrix) membranes revealed important advances in pervaporation. Therefore, the goal of this review is to compile and elucidate the latest advances (over the last 2–3 years) of zeolite applications in pervaporation membranes either combining zeolites or polymers. Here, particular emphasis has been focused on relevant insights and findings in using zeolites in pervaporative azeotropic separations and specific aided applications, together with novel concepts of membranes. A brief background of the pervaporation process is also given. According to the findings of this review, we provide future perspectives and recommendations for new researchers in the field.

Mixed Matrix Membranes Based on Fluoropolymers with m- and p-Terphenyl Fragments for Gas Separation Applications.

Novel mixed matrix membranes (MMMs) based on fluoropolymers with m- and p-terphenyl fragments and NaX zeolites were prepared. The fluoropolymers were synthesized by a one-pot, room-temperature, metal-free superacid-catalyzed stoichiometric and nonstoichiometric step polymerization of 2,2,2-trifluoroacetophenone with two multiring aromatic nonactivated hydrocarbons (p-terphenyl and m-terphenyl). MMMs were characterized by scanning electron microscopy (SEM) and infrared (Fourier transform infrared (FTIR)) spectroscopy and used in gas permeability tests. SEM analysis showed interfacial voids in MMMs prepared in N-methyl-2-pyrrolidone (NMP), The interfacial adhesion in the polymer–zeolite system was considerably improved when chloroform was used as a solvent. Permeability coefficients for pristine polymer membranes were 1.3-fold higher in CHCl3 than in NMP for p-terphenyl fragment and 2.0 times higher in NMP than in CHCl3 for the polymer with m-terphenyl fragment. The incorporation of NaX zeolites in the polymeric matrices improved the gas permeability coefficients compared to the pristine membranes. The effects of polymer architecture, casting solvent, and interaction between the organic matrix and the inorganic particles on the gas separation performance of the developed MMMs were investigated.

Effect of foaming technique and mixing temperature on the rheological characteristics of fine RAP-foamed bitumen mixtures

This paper evaluates and compares the differences in the rheological characteristics of the fine aggregate matrix (FAM) portion of plant produced Foamed Bitumen Mixtures (FBMs) by means of a mechanical foaming process, and by the incorporation of zeolites in combination with Reclaimed Asphalt Pavement (RAP) material. This evaluation explores, for the first time, the impact of plant production variations for half-warm, warm and hot processes (i.e. mixing temperatures around 90°C, 120°C and 160°C, respectively) on their rheological response. A fine Virgin-HMA, a fine HMA-RAP – no foaming technique -, and a 100% fine RAP mixture were also produced for comparison purposes. Dynamic Mechanical Analysis (DMA) tests were conducted on all evaluated FAM mixtures to determine their linear viscoelastic properties. Results indicate that the rheological response of the fine RAP-FBMs is influenced primarily by the contribution of the RAP binder in the total bitumen blend, and ageing of the fine RAP material, which were a function of the foaming technology and the production temperature of the materials.

Incorporation of Lactobacillus plantarum and zeolites in poultry feed can reduce aflatoxin B1 levels.

The aim of this work was to evaluate the incorporation of a freeze-dried probiotic strain (Lactobacillus plantarum CIDCA 83114) into zeolites. The bacteria-zeolite mixture was added to poultry feed together with thyme, and the obtained product was stored for 60days at 25°C and 60-70% relative humidity. The ability of the obtained product to remove aflatoxin B1 (AFB1) was studied. The highest bacterial viability was observed when 50% w/w bacteria were added to zeolites. The bacterial:zeolite mixtures were then incorporated into poultry feed containing or not thyme. Initial counts of L. plantarum were in the range of 1-2×108 CFU/g for all samples. In all cases, bacterial viability decreased one logarithmic order after 20days of storage, and three logarithmic orders after 60days. No significant viability loss was observed after exposure of the poultry feed to gastro-intestinal conditions. Freeze-dried L. plantarum and zeolite were able to remove AFB1, with an average reduction of 20 and 80%, respectively. Moreover, the freeze-dried bacteria-zeolite mixture was capable to remove up to 90% AFB1. This work contributes to enhance the nutritional quality of poultry feed, with a strong impact in production.

Pervaporation dehydration of binary and ternary mixtures of acetone, isopropanol and water using polyvinyl alcohol/zeolite membranes

Mixed matrix membranes were prepared by uniformly dispersing of zeolite particles in a polyvinyl alcohol matrix. After membrane characterization, the ability of the prepared membranes was examined toward pervaporation dehydration of binary and ternary mixtures of acetone, isopropanol and water because of their industrial importance. The effect of different parameters on the membrane performance was investigated and the best conditions were obtained. The results showed that, NaA zeolite particles significantly improved the separation performance of the membranes. The selectivity was increased with an increase of zeolite loading up to 5% wt. The best results were obtained for dehydration of isopropyl alcohol where the separation factor was calculated as 1881. Based on the findings of the research, the incorporation of NaA zeolites into the polymer matrix can be very effective for dehydration of acetone and isopropanol. The results show that the prepared membrane can be a good candidate for removal of water in acetone production from isopropyl alcohol.

Smectites and zeolites in ash from the 2010 summit eruption of Eyjafjallajökull volcano, Iceland

Hydrothermal alteration minerals are often incorporated in volcanic ash from phreatic and phreatomagmatic activity. Here we assess the presence and abundance of such minerals in the ash materials produced during the April-May 2010 initial phreatomagmatic (phase I) and subsequent magmatic (phases II and III) eruptions of Eyjafjallajokull volcano, Iceland. The results of X-ray diffraction analyses reveal significant quantities of smectites (up to 4 wt%, mainly as saponite) and zeolites (up to 7 wt%) in ash from phase I. While a minor amount of smectites (<0.5 wt%) is present in ash from the subsequent weak explosive activity (phase II), both smectites and zeolites are absent in phase III ash. This material was generated following abrupt rejuvenation of explosive activity in the absence of magma-ice/water interaction. Smectites and zeolites in phase I ash result primarily from scouring of altered volcanic rocks in the subsurface, although some may derive also from water-rock interaction within the summit ice cauldrons through which fragmented magma was injected. We show that incorporation of smectites and zeolites in phase I ash can explain its anomalously high specific surface area. Further, the presence of these minerals in ash may enhance its ability to act as ice nuclei as well as favour particle aggregation processes in the volcanic plume/cloud. Finally, the Eyjafjallajokull eruption represents another case in which ash fallout acted as an exogenic source of 2:1-type clay minerals in volcanic soils.

Synergistic effect of synthetic zeolites on flame-retardant wood-flour/polypropylene composites

Flame-retardant wood-plastic composites (WPCs) consisting of ammonium polyphosphate (APP) as flame retardant and four different concentrations (2, 4, 6, and 8wt%) of synthetic zeolites (type 4A and 13X) as synergistic agent were prepared. The results of thermogravimetry analysis showed that the inclusion of synthetic zeolites catalyzed the thermal degradation of WPCs. Both limiting oxygen index and cone calorimetry tests were used to evaluate the flame performance of WPCs, and the results proved that the addition of 4A or 13X zeolites had synergistic effect on the flame retardancy of WPCs. The residues of burned WPCs after cone calorimetry tests were characterized by scanning electron microscopy, energy dispersive spectroscopy, and Fourier transform infrared spectroscopy. All above data in series were integrated to speculate the synergistic mechanism. Moreover, all the measured mechanical tests proved that the incorporation of zeolites increased flexural properties and impact strength, and decreased tensile properties of WPCs.

The preparation and gas separation properties of zeolite/carbon hybrid membranes

Zeolite/carbon hybrid membranes with enhanced gas permeability were prepared by the incorporation of zeolites Y, β, or ZSM-5 into the precursor of polyamic acid and carbonization at high temperature. The effects of physical and chemical properties of zeolites and the preparation parameters, involving the agglomeration size and crystal diameter of zeolites, content and carbonization temperature, on the related gas separation performances were investigated. Results indicate that embedding the zeolites into carbon membrane can greatly increase the gas permeability of carbon membranes without losing the selectivity obviously. The properties of embedded zeolites and the preparation parameters greatly affect the gas separation performances of derived zeolite/carbon hybrid membranes. The gas permeability and selectivity of derived hybrid carbon membranes can be tuned by optimizing the embedded zeolite properties such as the agglomeration size and crystal diameter, and the preparation parameters such as the zeolite content and carbonization temperature. The effects of incorporating the zeolite into carbon membrane on enhancing the gas permeability might be attributed to the intactly ordered inner pore channels of embedded zeolite, which provides rapid and continuous diffusive routes for gas molecules and interfaced pores formed between the embedded zeolite and carbon matrix, which create new channels for gas diffusion in carbon membranes.

TUD-1: synthesis and application of a versatile catalyst, carrier, material…

The three-dimensional sponge-like mesoporous material TUD-1 is straightforward to prepare. Its synthesis can readily be modified to introduce metals into the framework of TUD-1, imparting many different catalytic activities. M-TUD-1 catalysts have proven to be very active, unlimited by diffusion and very stable. By combining two metals into one TUD-1 catalyst, synergy between Lewis and Brønsted acid sites could be induced; incorporation of zeolites similarly gave rise to synergy. In addition to successful applications in redox-, acid- and photo-catalysis TUD-1 proved to be an excellent carrier material for catalysts, enabling new applications. TUD-1 was used as a contrast agent and drug delivery system, indicating that this material is but at the beginning of its potential applications.

Effect of zeolites on chitosan/zeolite hybrid membranes for direct methanol fuel cell

Zeolites including 3A, 4A, 5A, 13X, mordenite, and HZSM-5 were incorporated into chitosan (CS) matrix to fabricate the hybrid membranes for direct methanol fuel cell (DMFC). Due to the presence of hydrogen bonds between CS and zeolite, the hybrid membranes displayed desirable thermal and mechanical stabilities. Through free volume characteristics analysis by positron annihilation lifetime spectroscopy (PALS) technique, it was found that incorporation of hydrophilic zeolites would increase the free volume cavity size whereas incorporation of hydrophobic zeolites would decrease the free volume cavity size. Through the investigations on water/methanol uptake, swelling, and methanol permeability, it was found that the membrane performance was highly dependent on the zeolite particle and pore size, content, and hydrophilic/hydrophobic nature. Based on the solution–diffusion mechanism, it was found that incorporation of hydrophobic zeolites increased the diffusion resistance of methanol and consequently decreased the methanol permeability, whereas incorporation of hydrophilic zeolites decreased the diffusion resistance of methanol and consequently increased the methanol permeability. Moreover, under the identical conditions, all the as-prepared membranes exhibited much lower methanol permeability than Nafion ® 117 while the proton conductivity of the membranes remained high enough for DMFC applications.

Development of polycarbonate based zeolite 4A filled mixed matrix gas separation membranes

The incorporation of fillers, blending with multifunctional low molecular-weight additives and their combination are investigated as alternatives for modifying the permselective properties of polymeric gas separation membranes. For this purpose, pure polycarbonate (PC), PC/ p-nitroaniline (pNA), PC/zeolite 4A and PC/pNA/zeolite 4A mixed matrix membranes were prepared by solvent-evaporation method using dichloromethane as solvent. Zeolite 4A was the filler and pNA was the low molecular-weight additive with multifunctional groups. The concentrations of pNA and zeolite 4A in the casting solution were changed between 1–5% (w/w) and 5–30% (w/w), respectively. Membranes were characterized by SEM, DSC and single gas permeability measurements of H 2, CO 2, O 2, N 2 and CH 4. Incorporation of zeolites to PC/pNA increased the T g but the incorporation of them to pure PC had no effect on the T g, suggesting that pNA induced an interaction between zeolite 4A and polymer matrix. The PC/pNA/zeolite 4A membranes had lower permeabilities but higher ideal selectivities than pure PC and PC/zeolite 4A membranes. The membrane with 1% (w/w) pNA and 20% (w/w) zeolite 4A showed a selectivity of 121.3 for H 2 over CH 4 and 51.8 for CO 2 over CH 4, whereas the H 2/CH 4 and CO 2/CH 4 selectivities for pure PC membranes were 40.9 and 23.6, respectively. The gas separation performance of the PC membranes was remarkably improved with the incorporation of zeolite 4A and small amounts of pNA into the membrane formulation.

Studies on poly(trimethylene terephthalate) filaments containing silver

Two methods were used to incorporate silver ions into poly(trimethylene terephthalate) (PTT) fibers. The first technique involved the direct addition of silver (I) sulfadiazine into PTT polymer prior to extrusion. The second method involved the use of silver-exchanged zeolites. Although no optimization with silver-exchanged zeolites was conducted, this study clearly showed that PTT fibers containing sufficient amounts of silver ions are effective in reducing pathological microorganisms such as Escherichia coli. Incorporation of silver-exchanged zeolites into PTT imparted a silver color to the fibers which may be attributed to the partial reduction of silver ions during spinning at 256°C. Because of the decomposition of silver (I) sulfadiazine, the spinnability of PTT fiber sample was not satisfactory and, therefore, this compound cannot be used as a carrier of silver ions in PTT. The thermal, tensile and antimicrobial properties of the spun filaments are reported in this paper.

Use of Ferricinium Exchanged Zeolite for Mediator Stabilization and Analytical Performances Enhancement of Oxidase-Based Carbon Paste Biosensors†

The carbon paste design allows bulk modification of the entire electrode material with the bio-component and the incorporation of a variety of different additives such as enzyme stabilizers, mediators, activators, or other compounds that can increase the stability, amplitude, and selectivity of the response signal. The incorporation of heterogeneous particles such zeolites in the modified carbon paste electrodes might engender an improvement of their analytical performances. We show here that the incorporation of zeolite, already exchanged with the cationic form of the redox mediator (YFcH), within GOx carbon paste bioelectrodes improves the analytical performances of the mediated glucose biosensor. Not only the inclusion of the redox mediator into the zeolite particles permits to extend the linear range and to enhance significantly the operational and storage stabilities, but unexpectedly it permits to speed up the response time. †To Pierre Coulet: Thank you for showing us that honesty is essential for stable and ever-lasting friendships.

Incorporation of zeolites into composite matrices

Zeolites KNaA and NaX were incorporated into composite matrix materials having organic and inorganic components. These composite materials were coated onto glass substrates, cured, and tested for nitrogen adsorption. Uptake capacities were always significantly higher for the NaX zeolite films compared to the KNaA zeolite films, as expected, due the zeolite pore sizes relative to the nitrogen molecule. Both thermal curing and UV curing were used in this study to initiate the crosslinking reactions that created the matrices. IR spectra demonstrated that some of the matrix materials bonded to the zeolite surfaces, whereas some did not. Post-synthesis oxidative degradation treatments were shown to affect the nitrogen uptake capacity. Thus, the choice of zeolite, the composition of the matrix materials, and post-synthesis treatments can all be used to tailor the effective pore dimensions of the composite film for subsequent separations or sensor applications.

Incorporation of nano-sized zeolites in membranes

The first incorporation of nano-sized zeolites in membranes is reported and polydimethylsiloxane membranes filled with colloidal silicalite-1 are applied in the pervaporation of ethanol–water mixtures.

Functional micro-concrete: The incorporation of zeolites and inorganic nano-particles into cement micro-structures

Functional micro-concrete: The incorporation of zeolites and inorganic nano-particles into cement micro-structures

Silylation To Improve Incorporation of Zeolites in Polyimide Films

The silylation of borosilicate with APTS ((γ-aminopropyl)triethoxysilane) is studied as a tool to improve zeolite incorporation in PI (polyimide) films. Among other experimental parameters, a quantification of the zeolite outer surface silanols is performed in order to determine the most appropriate silylation conditions. Xylene sorptions, NMR (nuclear magnetic resonance) spectroscopy, and measurements of the specific surface of the zeolites were performed to characterize the silylation. Finally, the silylated zeolite was incorporated in PI films on which tensile strength, density, and xylene sorption were measured.

Incorporation of Zeolites in Polyimide Membranes

Incorporation of Zeolites in Polyimide Membranes