Papers by Keyword: Intercalation

Abstract: Layered double hydroxide (LDH) composites intercalated with polyoxometalates (POMs) have emerged as pivotal materials spanning various scientific domains. This study explores the intercalation of Keggin-type POM anions into LDHs and investigates the roles of electrostatic interactions, hydrogen bonding, and the superchaotropic effect in this process. In this research endeavor, the successful intercalation of 3-charge Keggin-type POMs into LDH layers has been achieved using an exfoliation-reassembly technique. A comprehensive suite of characterization techniques, including XRD, FT-IR, SEM, and TGA, was utilized to confirm structural, morphological, and thermal modifications. Selectivity experiments further verified the predominant role of the superchaotropic effect. These findings provide valuable insights into the design and functionalization of LDH-based nanomaterials.

Abstract: For the purpose of synthesizing 2D-Material–Magnetic nanocomposites, several new modifications of existing 2D-materials synthesis methods by exfoliation and chemical synthesis from liquid charge are developed. Using them, graphene (G), graphene oxide (GO), reduced graphene oxide (rGO) and hexagonal boron nitride (h-BN) matrix magnetic nanocomposites for the first time are obtained by coating or intercalation their nanoparticles with ferromagnetic iron (Fe) or ferrimagnetic iron oxide – magnetite (Fe₃O₄). These materials are prospective for variety of high tech applications. In particular, h-BN–Fe₃O₄ composite nanoparticles can serve for neutron-capturing boron isotope ¹⁰B effective delivery agents in BNCT (Boron Neutron Capture Therapy) of cancer as they allow the controlling by an external magnetic field targeting to tumor tissue.

Abstract: Bentonite was modified through intercalation and calcination using a ZrOCl₂ pillaring solution. To create nano Ni/ZrO₂-bentonite catalyst, ZrO₂ pillared bentonite was impregnated using Ni(NO₃)₂•6H₂O precursor first, then followed by calcination and reduction. The physical-chemical properties of the catalyst was characterized by XRD (X-ray Diffractometer), FT-IR (Fourier Transform Infrared), surface acidity with NH₃ vapor adsorption method, SAA (Surface Area Analyzer) and TEM (Transmission Electron Microscope). The results of characterization with XRD showed specific peaks for montmorillonite minerals with a monoclinic crystalline type and its chemical composition (Ca)(Al,Mg)₆(Si₄O₁₀)₃(OH)₆.nH₂O and after pillarization showed a shift in basal spacing d₀₀₁ to the left (angle 2θ <5°). The typical peak indicating basal spacing d₀₀₁ shift towards a smaller angle of 2θ was not very apparent after impregnation with nickel metal. Qualitative determination of acidity after adsorption of ammonia showed characteristics at 1404-1635 cm^-1 wavenumbers with increasingly sharp spectra indicating increased acidity of the catalyst (Brǿnsted and Lewis acids). Surface area showed a significant increase from 27.385 m²/g to 174.208 m²/g after pillarization and impregnation of nickel metal.

Abstract: By mechanical blending method or melt extrusion method, several kinds of poymers and OMMT were selected with different mixing progress and conditions, and several polymer/OMMT nanocomposites with different substructure morphology were prepared. The properties of polymer/OMMT nanocomposites were investigated. Firstly, several types of OMMT were prepared with different layer spacing, the results of XRD and TEM showed that the OMMT with larger layer spacing would form exfoliation nanocomposites, and then the schemes explained the mechanism. The polyethylene (such as LDPE, HDPE, LLDPE) composited with the same OMMT indicated the influence of different molecular chain structure. Different morphology of PP/OMMT and EPDM/OMMT nano-composites were discussed to find the relationship of shear force effecting structure.

Abstract: Silylation, also known as silane grafting, is frequently used to organically modify montmorillonite (organo-Mt), which of properties were depended on the type of siloxane and intercalated interlayer structure of Mt, for construction of functional materials utilizing in a variety application of industry. We have synthesized organo-Mt using different siloxanes after Mt was firstly modified at three different surfactants of cationic cetyltrimethylammonium bromide (CTAB), anionic sodium oleate (So) and nonionic sorbitan monostearate (Span60) to identifying the effect of surfactants for silylation of Mt. The spectral and structural characters of the obtained products were characterized by a combination of X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), thermogravimetry (TG), and contact angle analysis. The basal spacing of the organo-Mt increased with surfactants loading. We found that CTAB can significantly increase the spacing between layers of Mt from 1.55nm to 1.90nm, load more siloxane on Mt. The average contact angles of CTAB-Mt-APTES and CTAB-Mt-PTES were 69.9±0.3° and 80.7±0.3°, which could be more prone to the interlayer locking effect. Our study showed that the charge of surfactants has significant influence for silylation of Mt, resulting in the loading amount of silane, interlayer structure, and the surface wetting properties.

Abstract: The acidification and intercalation of illite containing clays were studied for potential use as fillers for sulphonated poly (ether ether ketone) (SPEEK) composite membrane preparation and future proton exchange membrane fuel cells application. The acidification and dimethyl sulfoxide (DMSO) intercalation of illite clays have been studied by powder X-ray diffractometry, X-ray fluorescence spectrometry, and thermogravimetric analysis. SPEEK composite membranes were made with 1, 3 and 5% purified, acidified, DMSO intercalated clay fillers. SPEEK/clay composite membranes were characterized by proton conductivity, water uptake, and mechanical strength.

Abstract: A new method of layered silicate (montmorillonite) intercalation by polyvinylpyrrolidone in the solution under ultrasonic treatment is described in this work. The structure and thermophysical properties of the developed nanomodifier and the components rational ratio have been investigated. The effect of intercalated montmorillonite on physico-mechanical, thermophysical and insulating properties of polycaproamide PA-6 has been determined.

Abstract: The effect of milling on structure of kaolinite-urea intercalates were studied. Untreated and treated kaolinite samples were examined by Field scanning electron microscopy (FESEM), X-ray powder diffraction (XRPD) and Fourier transform infrared (FT-IR) spectroscopy. The basal spacing of kaolinite measured by X-ray powder diffraction (XRPD) increased from 1.02 to 3.62 nm after intercalation by urea. Significantly, nature of intercalation was reached through formation of hydrogen bonds between urea and both Si-O and AlOH groups of the interlayer surface of kaolinite.

Abstract: A nonsteroidal drug, flufenamic acid (FA) was successfully intercalated into magnesium-aluminium-layered double hydroxide, MAL for the formation of magnesium-aluminium-flufenamate-layered double hydroxide, MAF by self-assembly technique. As a result of the successful intercalation, basal spacing increased from 9.8 Å in the MAL to 23.5 Å in the MAF hybrid nanocomposite. The FTIR spectra of the MAF hybrid nanocomposite show resemblance peaks of the MAL and FA suggesting the inclusion of the organic compound into the MAL interlamellae. The percentage loading of FA was found to be 74.4 % (w/w) calculated from the percentage of carbon in the resulting material, MAF.

Abstract: Synthesis of a new hybrid nanocomposite materials, zinc-aluminium-fenoprofen, ZAF was successfully accomplished by self-assembly method with molar ratio of Zn to Al; R=2 at concentration of fenoprofen=0.3 M. As a result of the successful intercalation, the interlayer spacing expanded from 9.8 Å in the zinc-aluminium-layered double hydroxide, ZAL to 20.1 Å in the ZAF hybrid nanocomposite. The FTIR spectra of the ZAF show resemblance peaks of ZAL and fenoprofen indicating the inclusion of the organic compound into the LDH interlamellae. The percentage loading of the guest anion, fenoprofen in ZAL was estimated to be about 63.4% (w/w) calculated from the carbon content.