Author
Tomaz Arakaki
Bio: Tomaz Arakaki is an academic researcher from Federal University of Paraíba. The author has contributed to research in topics: Silica gel & Adsorption. The author has an hindex of 6, co-authored 9 publications receiving 145 citations.
Topics: Silica gel, Adsorption, Gibbs free energy, Aqueous solution, Titration
Papers
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TL;DR: In this paper, the silylating agent 3-[2-(2-aminoethylamino)ethylaminos]propyl-trimethoxysilane was previously immobilized onto silica gel in heterogeneous route, followed by incorporation of thioglycolic acid.
44 citations
TL;DR: This material was characterized by elemental analysis, IR spectroscopy, thermogravimetry, solid state 13C and 29Si NMR, and surface area measurement and employed as adsorbents for divalent heavy cations from aqueous solutions at room temperature and the isotherms were adjusted to a modified Langmuir equation.
Abstract: Silica gel surface has been modified in two reaction steps: (i) the silylating agent 3-mercaptopropyltrimetoxysilane was firstly immobilized to give a surface Sil-SH and (ii) this precursor incorporated an ethylene sulfide molecule to obtain the surface denoted Sil-SSH. This material was characterized by elemental analysis, IR spectroscopy, thermogravimetry, solid state 13C and 29Si NMR, and surface area measurement. These materials were employed as adsorbents for divalent heavy cations from aqueous solutions at room temperature and the isotherms were adjusted to a modified Langmuir equation. The maxima number of moles adsorbed were 1.0, 1.5, 1.6, 2.2, 2.4 and 3.3 mmol g(-1) for Co, Cu, Ni, Cd, Pb, and Hg, respectively.
28 citations
TL;DR: In this article, a modified Langmuir equation was used to fit the adsorption isotherms of a modified silica gel surface to the data obtained by suspending the solid in MCl 2 (M = Cu, Ni, and Co) aqueous solutions, yielding the maximum number of moles adsorbed as 1.04±−0.01, 1.89±-0.02, and 1.85±-1.
24 citations
TL;DR: Thioglycolic acid was immobilized onto silica gel surface using 3-aminopropyltrimethoxysilane as precursor silylating agent to yield silica by the batch method when similar chemisorption isotherms were observed for all cations.
23 citations
TL;DR: In this article, the amount of ethylenesulfide anchored on silica surface was estimated to be 0.80mmol−g −1, and the Δ H values of metal ion binding with the modified silica were found to be −11.10−±-0.5, −10.18−±−0.3, −5.65−± −0.2, −7.33−± 0.1, and −4.11−± ǫ 0.2
20 citations
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TL;DR: In this paper, the activation energy of the adsorption process was calculated based on the pseudo-second order rate constant, and it was shown that H2PO4− had the greatest affinity for the adsorbent surface.
305 citations
TL;DR: The results indicate that the structure of the materials affects the adsorption behavior and these materials show a potential for the application as effective and selective adsorbents for Hg(II) removal from water.
180 citations
TL;DR: In this article, the authors classified symmetric and asymmetric compartmental acyclic Schiff bases and their reduced polyamine analogues according to their synthetic procedures, i.e. the condensation ratio between the formyl (or keto) and amine precursors.
169 citations
TL;DR: Vermiculite, a 2:1 clay mineral, was applied as adsorbent for removal of cadmium, zinc, manganese, and chromium from aqueous solutions and showed good sorption potential for these cations.
166 citations
TL;DR: The application of MIPs with high affinity and excellent stereo-selectivity toward PAHs in SPE might offer a more attractive alternative to conventional sorbents for extraction and abatement of PAH-contaminated seawater.
150 citations