Comparison of Co(ii) adsorption by a crosslinked carboxymethyl chitosan hydrogel and resin: behaviour and mechanism

2017 ◽  
Vol 41 (9) ◽  
pp. 3487-3497 ◽  
Author(s):  
Wenqiang Luo ◽  
Zhishan Bai ◽  
Yong Zhu
Keyword(s):  
Adsorption Mechanism ◽  
Physical Adsorption ◽  
Carboxymethyl Chitosan ◽  
Chitosan Hydrogel

This article studies the possible chemical and physical adsorption mechanism for Co(ii) onto the crosslinked carboxymethyl chitosan hydrogel and resin.

Dialdehyde-β-cyclodextrin-crosslinked carboxymethyl chitosan hydrogel for drug release

2020 ◽  
Vol 231 ◽  
pp. 115678 ◽  
Author(s):  
Chaoqian Lou ◽  
Xiuzhi Tian ◽  
Haibo Deng ◽  
Yingxia Wang ◽  
Xue Jiang
Keyword(s):  
Drug Release ◽  
Carboxymethyl Chitosan ◽  
Chitosan Hydrogel

The Adsorption Behavior of Modified Peanut Shells for Cr (VI)

2013 ◽  
Vol 781-784 ◽  
pp. 2189-2194
Author(s):  
Yi Hua Jiang ◽  
Xin Long Jiang
Keyword(s):  
Adsorption Mechanism ◽  
Physical Adsorption ◽  
Peanut Shell ◽  
Chemical Adsorption ◽  
Chemical Methods ◽  
Ir Spectrometry ◽  
Freundlich Isotherms ◽  
Reduction Processes ◽  
Peanut Shells ◽  
Adsorption Activation Energy

The adsorption of Cr(VI) by modified peanut shell has been investigated using chemical methods and IR spectrometry. The optimal condition for the adsorption of Cr(VI) by modified peanut shell is at 308 K and pH = 1.0, which gives a static saturated adsorption capacity of 14.15 mg·g-1, an apparent adsorption rate constant of k298 = 2.43 × 10-4 s-1, and an apparent adsorption activation energy of 10.58 kJ·mol-1. The adsorption follows the Langmuir and Freundlich isotherms and the liquid film diffusion is the controlling process of the adsorption. The adsorption thermodynamic parameters are ΔH = 125.58 kJ·mol-1, ΔS = 0.473 9 kJ·mol-1·K-1, ΔG = -17.81– -27.27 kJ·mol-1. Small amount of desorption is observed only at pH > 11. Adsorption mechanism of modified peanut shells for Cr(VI) was both physical adsorption and chemical adsorption of adsorbent "adsorption-oxidation and reduction processes".

Surface and Electrochemical Studies of Thin Film Diamond

2006 ◽  
Vol 956 ◽  
Author(s):  
John Foord ◽  
David Opperman
Keyword(s):  
Adsorption Mechanism ◽  
Physical Adsorption ◽  
Aqueous Media ◽  
Electrochemical Studies ◽  
Power Ultrasound ◽  
Diamond Electrode ◽  
Adsorption Processes ◽  
Electrode Interface ◽  
Protein Bovine Serum Albumin ◽  
Positively Charged

ABSTRACTThe behavior of diamond electrodes for electrochemical applications in aqueous media containing the protein bovine serum albumin has been explored, to examine the degree of electrode poisoning which occurs. Although the diamond electrode retains good activity in such solutions, electrode fouling is found at long contact times due to protein adsorption. Two adsorption processes are observed. The first is a simple physical adsorption mechanism, and can be simply reversed by washing the electrode in water. The second mechanism is only observed when negative potentials are applied to the diamond electrode and is attributed to the attraction and reaction of the positively charged protein at the electrode interface. Electrode poisoning is also observed in the presence of power ultrasound, although the electrochemical signals are usefully enhanced under these conditions due to enhanced mass transport to the electrode surface.

scholarly journals A Comparison Study of Mechanism: Cu2+Adsorption on Different Adsorbents and Their Surface-Modified Adsorbents

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Yaqin Yu ◽  
Xinrui Li ◽  
Jiemin Cheng
Keyword(s):  
Carbon Black ◽  
Adsorption Mechanism ◽  
Environmental Fate ◽  
Physical Adsorption ◽  
Hexadecyltrimethylammonium Bromide ◽  
Significant Implication ◽  
Isothermal Adsorption ◽  
Oxidized Carbon ◽  
Modified Adsorbents ◽  
Organic Bentonite

The isothermal adsorption kinetics of Cu2+onto Carbon Black (CB) and Oxidized Carbon Black (OCB) were studied under different solution conditions and compared with bentonite and organic bentonite with the hexadecyltrimethylammonium bromide (HDTMA). The adsorption capacities followed the order of OCB > CB > organic bentonite > bentonite, which was consistent with the orders of their surface roughness and specific surface area. The Fourier transmission infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and transmission electron microscope (TEM) were used to explore the adsorption mechanism at molecular level. The adsorption process onto CB was physical adsorption. However, with the increase of oxygen-containing functional groups (C=O, C-O, and CNO), the chelation adsorption onto OCB became gradually dominant except physical adsorption. The ion exchange adsorption was the major adsorption mechanism of bentonite. The compounds were introduced into clay interlayer by complexing reaction with Cu2+, which improved the adsorption capacity of organic bentonite. The results present a significant implication for the environmental fate assessment of heavy metal pollution.

scholarly journals DFT Calculations and Experimental Study to Inhibit Carbon Steel Corrosion in Saline Solution by Quinoline-2-One Derivative

2021 ◽  
Vol 18 (1) ◽  
pp. 0113
Author(s):  
Rehab Majid Kubba ◽  
Mustafa Alaa Mohammed ◽  
Luma S. Ahamed
Keyword(s):  
Carbon Steel ◽  
Density Functional ◽  
Adsorption Mechanism ◽  
Saline Solution ◽  
Physical Adsorption ◽  
Steel Corrosion ◽  
Equilibrium Geometry ◽  
Functional Theory ◽  
Carbon Steel Surface ◽  
Chemical Inhibition

A theoretical and protection study was conducted of the corrosion behavior of carbon steel surface with different concentrations of the derivative (Quinolin-2-one), namly (1-Amino-4,7-dimethyl-6-nitro-1H-quinolin-2-one (ADNQ2O)). Theoretically, Density Functional Theory (DFT) of B3LYP/ 6-311++G (2d, 2p) level was used to calculate the optimized geometry, physical properties and chemical inhibition parameters, with the local reactivity to predict both the reactive centers and to locate the possible sites of nucleophilic and electrophilic attacks, in vacuum, and in two solvents (DMSO and H2O), all at the equilibrium geometry. Experimentally, the inhibition efficiencies (%IE) in the saline solution (of 3.5%) NaCl were studied using potentiometric polarization measurements. The results revealed that the (%IE) for carbon steel corrosion by ADNQ2O is (89.88%). The obtained thermodynamic parameters support the physical adsorption mechanism. The adsorption followed the Langmuir isotherm. The surface change on carbon steel was studied using SEM (Scanning Electron Microscopy).

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