High-loading Ga-exchanged MFI zeolites as selective and coke-resistant catalysts for nonoxidative ethane dehydrogenation

In this paper, we investigated the effects of Ga loading amount and H2 treatment temperature for reductive solid-state ion-exchange reaction on the generated Ga species in Ga-exchanged MFI zeolites (Ga-MFIs)...

Colorimetric sensor array for rapid discrimination of edible oil species based on halogen ion exchange reaction between CsPbBr3 and iodide

Peroxides in edible oils, measured by peroxidation value for their amount, are closely related to human health. Long-term consumption of edible oils with high peroxidation values can lead to a...

Thermal behavior of Sr-form of gordaite

Cation-exchanged Sr-form of gordaite was successfully obtained from Ca-form of gordaite by an ion-exchange reaction. Data of XRD, SEM-EDS and DTA-TG-MS were used to characterize the Sr-form. Thermal decomposition of Sr-gordaite was studied for the first time in regards of thermal events and mass loss during volatile releasing. It was found similarity with Sr-gordaite and Ca-gordaite in terms of processes, type, and amount of volatiles released, but also some differences were found concerning the temperature correspondence of the volatiles evolving and the type of thermal decomposition products. The influence of the exchangeable cations (Na, Ca, or Sr) on the dehydration of the interlayer in the gordaite type structure were also established.

Physical–Chemical Exfoliation of n-Alkylamine Derivatives of Layered Perovskite-like Oxide H2K0.5Bi2.5Ti4O13 into Nanosheets

In the present work, we report the results on exfoliation and coating formation of inorganic–organic hybrids based on the layered perovskite-like bismuth titanate H2K0.5Bi2.5Ti4O13·H2O that could be prepared by a simple ion exchange reaction from a Ruddlesden–Popper phase K2.5Bi2.5Ti4O13. The inorganic–organic hybrids were synthesized by intercalation reactions. Exfoliation into nanosheets was performed for the starting hydrated protonated titanate and for the derivatives intercalated by n-alkylamines to study the influence of preliminary intercalation on exfoliation efficiency. The selected precursors were exfoliated in aqueous solutions of tetrabutylammonium hydroxide using facile stirring and ultrasonication. The suspensions of nanosheets obtained were characterized using UV–vis spectrophotometry, dynamic light scattering, inductively coupled plasma spectroscopy, and gravimetry. Nanosheets were coated on preliminarily polyethyleneimine-covered Si substrates using a self-assembly procedure and studied using atomic force and scanning electron microscopy.

Study on the synthesis of antibacterial plastic by using silver nanoparticles doped in zeolite framework

Silver nanoparticles (AgNPs) doped in the zeolite framework (AgNPs/Z) were successfully synthesized by γ-irradiation in ethanol solution of silver ion-zeolite (Ag+/Z) prepared by ion exchange reaction between silver nitrate (AgNO3) and zeolite 4A. The effects of the Ag+ concentration and irradiation dose on the formation of AgNPs/Z were also investigated. AgNPs/Z with the silver content of about 10,000 ppm and the average particle size of AgNPs of about 27 nm was characterized by ultraviolet-visible spectroscopy, powder X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM). Firstly, AgNPs/Z was added into PP resins for creation of PP-AgNPs/Z masterbatch (Ag content of ~10.000 ppm) and then PP-AgNPs/Z plastics were preapared by mixing masterbatch with PP resins. The antibacterial activity of the PP-AgNPs/Z plastics was investigated against Gram-negative bacteria Escherichia coli (E. coli). The results showed that PP-AgNPs/Z plastic contained 100 ppm of Ag possessed a high antibacterial property, namely the bactericidal effect was more than 96 % on the platic surface. In conclusion, possessing many advantages such as: vigorously antibacterial effect and good dispersion in plastic matrix, AgNPs/Z is promising to be applied as bactericidal agent for plastic industry.

Fabrication of Diaminodiphenylmethane Modified Ammonium Polyphosphate to Remarkably Reduce the Fire Hazard of Epoxy Resins

A novel diaminodiphenylmethane (DDM) modified ammonium polyphosphate (APP) flame retardant, DDP, was successfully synthesized via ion-exchange reaction. DDP was introduced into epoxy resins (EPs) to reduce flammability. A comparable level of DDP exerts better flame-retardant and smoke suppression efficiencies in EP than APP. An EP blend containing 15 wt% DDP displays a limiting oxygen index (LOI) value of 37.1% and a UL 94 V-0 rating, and further exhibits a 32.3% reduction in total heat release and a 48.0% reduction in total smoke production compared with pure EP. The presence of DDP greatly facilitates char formation during combustion, and the char mass from thermal decomposition of an EP blend is 37.8% smaller than that of an EP blend containing 15 wt% DDP at 800 °C. The incorporation of DDP into EP blends has a smaller impact on the glass transition temperature and tensile strength than those of a comparable level of APP. This reflects the better compatibility of DDP with the EP matrix compared with that for APP.

Removal of U (VI) From Aqueous Solution By Effective Bio-Adsorbent From Walnut Shell And Cellulose Composites Stabilized Iron Sulfide Nanoparticle

FeS nanoparticles were easily aggregated and oxidized in the natural environment due to van der Waals forces between nanoparticles. Biochar could be used as a carrier to inhibit the agglomeration and oxidization of FeS nanoparticles. An efficient bio-adsorbent (CFeS-WS) from walnut shell (WS) and cellulose composites stabilized iron sulfide nanoparticle was synthesized by the modified method. It also was determined by SEM, EDS, XRD and FT-IR, respectively. The removal of U(VI) ions from aqueous solution by CFeS-WS were conducted. The reaction mechanism between CFeS-WS and U(VI) ions also were discussed in details. The experimental results were showed that the biochar successfully was supported with cellulose/FeS composites (CFeS). CFeS-WS exhibited an excellent removal performance for U(VI) ions in solution. The adsorption process of U(VI) ions by CFeS-WS was more consistent with pseudo second-order kinetic model and Langmuir isotherm model. The proposed reaction mechanism of U(VI) ions removal by CFeS-WS mainly consisted of ion exchange reaction, reduction reaction, hydrogen bonding and functional group, and pore of adsorbent filling. Recycle experiment indicated that CFeS-WS was a cost-effective bio-adsorbent.