Permanganate ions were adsorbed on carbonate intercalated Co-Al-layered double hydroxide (Co-Al-LDH) and MoS2 and after a while the adsorbed ions were reduced to MnO2. Reduction of adsorbed ion was catalyzed on the surface of carbonate intercalated Co-Al-LDH but ions reacted with MoS2 surface. Adsorption kinetic tests were carried out at different temperatures, ionic strengths, pH, initial adsorbate concentrations and shaking rates.
View Article and Find Full Text PDFAdsorption of Alizarin Red S (ARS) on graphene oxide/poly(amidoamine) (GO/PAMAM) was studied at different ARS initial concentrations, temperatures, pHs, shaking rates and contact times. Adsorption sites of GO/PAMAM were phenolic -OHgroup of GO and amine groups (-NH2, -NH3+ and -NHR2+) of PAMAM dendrimer moieties of GO/PAMAM. At pH = 2 and 318 K, maximum adsorption capacity of the adsorbent was 1275.
View Article and Find Full Text PDFMaterials (Basel)
March 2018
Graphene oxide/poly(amidoamine) (GO/PAMAM) nanocomposite adsorbed high quantities of congo red (CR) anionic dye in 0.1 M NaCl solution, with the maximum adsorption capacity of 198 mg·g. The kinetics and thermodynamics of adsorption were investigated to elucidate the effects of pH, temperature, shaking rate, ionic strength, and contact time.
View Article and Find Full Text PDFThe goal of the current research was to critically examine the role of the shape and the size of contaminated particles for an accurate prediction of membrane fouling phenomenon. Polycarbonate flat membranes (PC) with uniform pore sizes of 0.05 and 0.
View Article and Find Full Text PDFThe goal of the present study was to investigate the influence of latex particle aggregation on membrane fouling attachments and the ultrafiltration performance of simulated latex effluent using Cetyltrimethyl Ammonium Bromide (CTAB) as a cationic surfactant. Hydrophilic polysulfone and ultrafilic flat heterogeneous membranes, with molecular weight cut off (MWCO) of 60,000 and 100,000, respectively, as well as hydrophobic polyvinylidene difluoride with MWCO of 100,000, were used under a constant flow rate and cross-flow mode in ultrafiltration of latex solution. In addition, a polycarbonate flat membrane with uniform pore size of 0.
View Article and Find Full Text PDFMaterials (Basel)
April 2014
Metal-organic frameworks (MOFs) are a new class of microporous materials that possess framework flexibility, large surface areas, "tailor-made" framework functionalities, and tunable pore sizes. These features empower MOFs superior performances and broader application spectra than those of zeolites and phosphine-based molecular sieves. In parallel with designing new structures and new chemistry of MOFs, the observation of unique breathing behaviors upon adsorption of gases or solvents stimulates their potential applications as host materials in gas storage for renewable energy.
View Article and Find Full Text PDFOver the past decades, organic-inorganic hybrid polymers have been applied in different fields, including the adsorption of pollutants from wastewater and solid-state separations. In this review, firstly, these compounds are classified. These compounds are prepared by sol-gel method, self-assembly process (mesopores), assembling of nanobuilding blocks (e.
View Article and Find Full Text PDFSynthesis of three-dimensional anisotropic microparticles using a simple one-step microfluidic-based method is described. The method exploits the nonuniformity of the polymerizing UV light, UV absorption by opaque nanoparticles in the precursor solution, and discontinuous photomask patterns to make magnetic and non-magnetic microparticles in a twodimensional microchannel. Numerical simulations of monomer conversion in the microfluidic channel are performed to predict the manufactured particle shape.
View Article and Find Full Text PDFWe demonstrate an alternative route to tune the morphology of zeolite L crystals using C(2)H(5)OH as the co-solvent in the synthesis gel. A low aspect ratio (0.2 to 0.
View Article and Find Full Text PDFThe synthesis, characterization, and growth rates of aluminum- and germanium,aluminum-substituted silicalite-1 (Al-silicalite-1, Ge,Al-silicalite-1) materials grown from clear solutions are reported. In the case of aluminum substitution, the crystallinity of the materials as determined by powder X-ray diffraction (PXRD) decreases with increasing aluminum content, as does the micropore volume determined by nitrogen adsorption and the growth rate determined by in situ small-angle X-ray scattering (SAXS). The final materials possess slightly lower Si/Al ratios than the initial synthesis mixtures based on X-ray fluorescence analysis.
View Article and Find Full Text PDFThe synthesis, characterization, and growth of Ge-silicalite-1 from optically clear solutions are reported. Ge-silicalite-1 is readily formed from optically clear solutions of TEOS, TPAOH, water, and a germanium source at 368 K. X-ray fluorescence (XRF) is used to determine the Si/Ge ratio and indicates that germanium inclusion is typically 30-50% of that in the actual mixture.
View Article and Find Full Text PDFIn situ small-angle X-ray scattering (SAXS) is used to investigate the influence of alcohol identity and content on silicalite-1 growth from clear solutions at 368 K. Several tetraalkyl orthosilicates (Si(OR)4, R = Me, Pr, and Bu) are used to synthesize silicalite-1 from clear solution mixtures comparable to those previously investigated (i.e.
View Article and Find Full Text PDFSmall-angle X-ray scattering (SAXS) has been used to quantify how perturbations of the tetrapropylammonium (TPA) cation structure affect the growth of silicalite-1 from clear solutions at 368 K. Alkyltripropylammonium (RN(C3H7)3 +OH-, R = Me, Et, Bu, and Pe), dialkyldipropylammonium (R2N(C3H7)2 +OH-, R = Et and Bu), and bis-1,6-(tripropylammonium)hexamethylene dihydroxide (TPA-dimer) cations are used as structure-directing agents (SDAs) to synthesize silicalite-1 from clear solution mixtures comparable to those that have been previously investigated for the TPAOH mediated synthesis (i.e.
View Article and Find Full Text PDFThis work investigates nanoparticle formation and zeolite growth in several tetraethyl orthosilicate (TEOS)/organocation/water solutions heated at 368 K using small-angle X-ray scattering. The effect of several synthesis parameters including organocation identity, hydroxide content, alkali content, synthesis temperature, ethanol content, and seeding are investigated. In all cases the TEOS/organocation/water solutions lead to colloidal silica nanoparticles both after aging at room temperature and after hydrothermal treatment.
View Article and Find Full Text PDFSolution 29Si NMR spectroscopy results of zeolite precursor solutions of composition 1 SiO2:4 C2H5OH:0.36/n R+n[OH-]n:20 H2O are reported. This work employs isotopically enriched 29Si materials to aid in spectral interpretation.
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