Physico-Chemical Properties of Nano ZrO2-Pillared Bentonite with Nickel as Supporting Metal

2020 ◽  
Vol 30 ◽  
pp. 9-17
Author(s):  
Mohamad Mirzan ◽  
Akhmad Syoufian ◽  
Karna Wijaya

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.

2010 ◽  
Vol 8 (1) ◽  
pp. 31-36
Author(s):  
Rodiansono Rodiansono ◽  
Reda Ariyantie ◽  
Abdullah Abdullah

Preparation of a kaolin-hydroxyl chromium composite and characterization of its physico-chemical properties were conducted. The olygomer hydroxyl-chromium was prepared by adding Na2CO3 to 0.1 M chromium nitrate solution (ratio OH/Cr = 2) and then dried at 110 oC and 400 oC for 4 h. Characterization of kaolin-hydroxyl chromium composite includes determination of acidity, functional groups, basal spacing, and surface area (BET-N2 sorption analyzer). The result showed that intercalation of hydroxyl chromium resulted in the decreasing of basal spacing but increased the specific surface area of kaolin. Drying of the intercalated kaolin at 400 oC decreased surface area, total volume pore and pore radius. FT-IR spectra showed that hydroxyl-chromium detected at wavelength of 2925 and 2855 cm-1.   Keywords: natural kaolin, intercalation, olygomer hydroxyl-chromium, kaolin-hydroxyl chromium composite


2009 ◽  
Vol 24 (9) ◽  
pp. 2845-2854 ◽  
Author(s):  
Balaji P. Mandal ◽  
Vinita Grover ◽  
Mrinal R. Pai ◽  
Avesh K. Tyagi

Effect of H2O2 on synthesis and powder properties such as surface area and agglomerate size of nanocrystalline Ce0.8M0.2O1.90 (M: Sm, Gd) was explored by treating cerium nitrate and rare-earth nitrate with NaOH in the presence/absence of H2O2. The resultant products were characterized by x-ray diffraction, Raman spectroscopy, thermo-gravimetry–differential thermal analysis, dynamic light scattering, surface area analysis, high-resolution transmission electron microscopy, and x-ray photoelectron spectroscopy. The presence of H2O2 was found to have a profound effect on powder properties such as surface area and particle size of these doped ceria samples and results in smaller crystallite size, softer agglomerates, and larger surface area. A mechanism is proposed to explain the observed better powder properties of the samples. It was also shown that the samples prepared in the presence of H2O2 can lower the conversion temperature of CO to CO2, proving these to be better catalysts. Interestingly, temperature-programmed reduction studies on Sm3+-doped samples showed that the doping in conjunction with the use of H2O2 leads to enhanced reduction properties of the samples over multiple cycles.


2019 ◽  
Vol 27 ◽  
pp. 31-37
Author(s):  
Karna Wijaya ◽  
Akhmad Syoufian ◽  
Ade Fitroturokhmah ◽  
Wega Trisunaryanti ◽  
Dita Adi Saputra ◽  
...  

It has been carried out preparation of Chrom/Nanocomposite ZrO2-Pillared Bentonite catalyst with varying the amount of impregnating precursor at 0 to 3% (w/w). Material characterization of catalyst was carried out using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Infrared Spectroscopy (IR), Transmission Electron Microscope (TEM), Brunauer, Emmett, Teller (BET) and acidity measurement of ammonia-adsorption method. The results of research showed that pillarization was able to increase the basal spacing, surface area, diameter of pore and total volume of pore in catalyst, however increasing of impregnated Cr metal on bentonite caused the decreasing of basal spacing and surface area of catalyst but it would also caused the increasing amount of acid site. The experimental results showed that the catalyst could convert the castor oil into a liquid phase of 78.80% (w/w) with a biogasoline content of 32,73% (w/w).


2013 ◽  
Vol 832 ◽  
pp. 589-595 ◽  
Author(s):  
N.A. Edama ◽  
A. Sulaiman ◽  
K.H. Ku Hamid ◽  
M.N. Muhd Rodhi ◽  
Mohibah Musa ◽  
...  

This study analyzed the effects of sulphuric acid (H2SO4) treatment on pysico-chemical properties and morphological changes of clay obtained from Sg. Sayong, Perak. The clay was ground and sieved to <150μm and treated with different concentrations of H2SO4. The treatment was completed by refluxing the clay with different concentration of H2SO4 (1M, 5M and 10M ) at 100 °C for 4 hours and followed by calcination at 500 °C for 1 hour. The physic-chemical properties and morphological changes of the untreated and treated clay were compared using Surface Area Analyser, X-Ray Diffraction (XRD), Field Emission Scanning Electron Micrograph (FESEM), X-Ray Diffraction (XRD) and Fourier Transformed Infrared Spectroscopy (FTIR). The results showed that acid treatment of 5M increased the surface area from 25 m2/g to 75 m2/g and the pore volume increased from 0.1518 cc/g to 0.3546 cc/g. The nanopore size of the clay decreased from 24.8 nm to 19.4 nm after treated with acid. This can be explained due to the elimination of the exchangeable cations and generation of microporosity. The results of XRF showed SiO2 increased from 58.34% to 74.52% and Al2O3 reduced from 34.6% to 18.31%. The mineral oxides such as Fe2O3, MgO, CaO, K2O and TiO2 also reduced. This concluded that H2SO4 treatment has led to significant removal of octahedral Al3+, Fe3+ cations and other impurities. In conclusion, this study showed the physico-chemical properties and morphology of Sayong clay were improved once treated with H2SO4 and therefore suggests better supporting material for enzyme immobilization.


Pharmaceutics ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 263 ◽  
Author(s):  
Maria Letizia Manca ◽  
Iris Usach ◽  
José Esteban Peris ◽  
Antonella Ibba ◽  
Germano Orrù ◽  
...  

New three-dimensionally-structured hybrid phospholipid vesicles, able to load clotrimazole in a high amount (10 mg/mL), were obtained for the first time in this work by significantly reducing the amount of water (≤10%), which was replaced with a mixture of glycerol and ethanol (≈90%). A pre-formulation study was carried out to evaluate the effect of both the composition of the hydrating medium and the concentration of the phospholipid on the physico-chemical properties of hybrid vesicles. Four different three-dimensionally-structured hybrid vesicles were selected as ideal systems for the topical application of clotrimazole. An extensive physico-chemical characterization performed using transmission electron microscopy (TEM), cryogenic transmission electron microscopy (cryo-TEM), 31P-NMR, and small-angle X-ray scattering (SAXS) displayed the formation of small, multi-, and unilamellar vesicles very close to each other, and was capable of forming a three-dimensional network, which stabilized the dispersion. Additionally, the dilution of the dispersion with water reduced the interactions between vesicles, leading to the formation of single unilamellar vesicles. The evaluation of the in vitro percutaneous delivery of clotrimazole showed an improved drug deposition in the skin strata provided by the three-dimensionally-structured vesicles with respect to the commercial cream (Canesten®) used as a reference. Hybrid vesicles were highly biocompatible and showed a significant antifungal activity in vitro, greater than the commercial cream Canesten®. The antimycotic efficacy of formulations was confirmed by the reduced proliferation of the yeast cells at the site of infection in vivo. In light of these results, clotrimazole-loaded, three-dimensionally-structured hybrid vesicles appear to be one of the most innovative and promising formulations for the treatment of candidiasis infections.


2017 ◽  
Vol 744 ◽  
pp. 441-445
Author(s):  
Norhafiza Mohd Salleh ◽  
Siti Halimah Sarijo ◽  
Anizah Kalam

A herbicide, 3,4-Dichlorophenoxy acetic acid (34D) was successfully intercalated into the zinc layered hydroxide (ZLH) by direct reaction with zinc oxide (ZnO) to form a new organic-inorganic zinc layered hydroxide-3,4-Dichlorophenoxy acetate (Z34D) under an aqueous environment. The pH of the solution was adjusted to 7.5 using 2 M sodium hydroxide (NaOH). The pure phase and well-ordered was synthesized at 0.3 M Z34D. PXRD patterns show well-ordered nanohybrid material with basal spacing at 26.1 Å. The percentage loading of 34D in the Z34D is 57.5 % (w/w) calculated based on the percentage of carbon in the sample. FESEM shows the ZnO precursor has very fine granular structure and transformed into agglomerate structure when the nanohybrid are formed. This work shows that the nanohybrid of Z34D can be synthesized using simple, direct-reaction method.


Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1603
Author(s):  
Yusha Imtiaz ◽  
Beza Tuga ◽  
Christopher W. Smith ◽  
Alexander Rabideau ◽  
Long Nguyen ◽  
...  

Polysaccharides have been shown to have immunomodulatory properties. Modulation of the immune system plays a crucial role in physiological processes as well as in the treatment and/or prevention of autoimmune and infectious diseases. Cellulose nanocrystals (CNCs) are derived from cellulose, the most abundant polysaccharide on the earth. CNCs are an emerging class of crystalline nanomaterials with exceptional physico-chemical properties for high-end applications and commercialization prospects. The aim of this study was to design, synthesize, and evaluate the cytotoxicity of a series of biocompatible, wood-based, cationic CNCs as potential immunomodulators. The anionic CNCs were rendered cationic by grafting with cationic polymers having pendant +NMe3 and +NH3 moieties. The success of the synthesis of the cationic CNCs was evidenced by Fourier transform infrared spectroscopy, dynamic light scattering, zeta potential, and elemental analysis. No modification in the nanocrystals rod-like shape was observed in transmission electron microscopy and atomic force microscopy analyses. Cytotoxicity studies using three different cell-based assays (MTT, Neutral Red, and LIVE/DEAD®) and three relevant mouse and human immune cells indicated very low cytotoxicity of the cationic CNCs in all tested experimental conditions. Overall, our results showed that cationic CNCs are suitable to be further investigated as immunomodulators and potential vaccine nanoadjuvants.


Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 114 ◽  
Author(s):  
Vincenzo De Leo ◽  
Sante Di Gioia ◽  
Francesco Milano ◽  
Paola Fini ◽  
Roberto Comparelli ◽  
...  

Curcumin is a natural polyphenol with strong antioxidant activity. However, this molecule shows a very poor bioavailability, instability, and rapid metabolism in vivo. In this work curcumin was loaded in Eudragit-coated liposomes to create a gastroresistant carrier, able to protect its load from degradation and free it at the site of absorption in the colon region. Small unilamellar vesicles were prepared and coated with Eudragit by a pH-driven method. The physico-chemical properties of the prepared systems were assessed by light scattering, transmission electron microscopy, infrared spectroscopy, and differential scanning calorimetry. The uptake of vesicles by Caco-2 cells and the anti-oxidant activity in cells were evaluated. The produced vesicles showed dimensions of about forty nanometers that after covering with Eudragit resulted to have micrometric dimensions at acid pH. The experiments showed that at pH > 7.0 the polymeric coating dissolves, releasing the nanometric liposomes and allowing them to enter Caco-2 cells. Delivered curcumin loaded vesicles were then able to decrease significantly ROS levels as induced by H2O2 in Caco-2 cells. The proposed work showed the possibility of realizing effective gastroresistant curcumin liposome formulations for the delivery of antioxidant molecules to Caco-2 cells, potentially applicable to the treatment of pathological conditions related to intestinal oxidative stress.


2011 ◽  
Vol 236-238 ◽  
pp. 538-542
Author(s):  
Yong Jun Liu

The deactivation behavior of industrial hydrodemetallization catalysts was investigated in the presented work. The main objective of the study is to contribute to a better understanding of the nature of the coke and metal deposition on the used catalysts by applying chemical analysis and various advanced analytical techniques, such as X-ray diffraction analysis (XRD), thermal gravimetric analysis (TGA), transmission electron microscopy (TEM), and solid-state carbon-13 nuclear magnetic resonance spectroscopy (13C NMR). The results are discussed scientifically based on the physico–chemical properties of origin and used catalysts.


2020 ◽  
Vol 32 (6) ◽  
pp. 1335-1342
Author(s):  
Kh. E. Yunusov ◽  
A.A. Sarymsakov ◽  
S.V. Mullajonova ◽  
F.M. Turakulov ◽  
S. Sh. Rashidova

Stable silver nanoparticles in solutions of sodium-carboxymethylcellulose (Na-CMC) were synthesized and their structure and physico-chemical properties were evaluated. The form and sizes of silver nanoparticles formed in solutions of CMC and cotton fabrics were studied using UV-VIS spectroscopy, atomic force microscopy and transmission electron microscopy methods. It was found that silver nitrate concentration increase in sodium carboxymethylcellulose solutions, as well as photoirradiation of the hydrogel lead to the changes of the silver nanoparticles size and shape. Investigations have also shown that spherical silver nanoparticles with sizes of 5-35 nm and content of 0.0086 mass% in cotton fabrics possess high bactericidal activity. Stabilization of silver nanoparticles has preserved bactericidal and bacteriostatic activities during the washing of cotton fabrics and textiles on their base.


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