Control of the adsorption capacity of a carbon sorbent with respect to protein molecules by surface modification with aminocaproic acid

2010 ◽  
Vol 83 (3) ◽  
pp. 406-413 ◽  
Author(s):  
V. A. Likholobov ◽  
L. G. P’yanova ◽  
O. N. Baklanova ◽  
V. A. Drozdov ◽  
L. S. Luzyanina ◽  
...  
2020 ◽  
Vol 42 (10) ◽  
pp. 472-481
Author(s):  
Hee So Oh ◽  
Jae-Soo Chang

Objectives : The physicochemical characteristics of Mg-biochar composites derived from kelp and pine after pretreatment with MgCl2 were analyzed, and their adsorption capacities for an anionic dye, Congo red (CR), were evaluated.Methods : After pretreating 60 g of kelp and pine sawdust in 1 L of 0.1 M MgCl2・6H2O, the raw materials were pyrolyzed at 500℃ to produce Mg-biochar composites (kelp based KB-Mg and pine based PB-Mg). The fundamental physicochemical characteristics of the Mg-biochar composites were examined, and their adsorption capacities for CR were investigated using different initial pH values, adsorption kinetic models, and adsorption isotherm models.Results and discussion : The Mg-biochar composites showed the development of uniform deposits of Mg minerals primarily as MgO crystal on the surface by the surface modification with MgCl2. When the pristine biochars were surface-modified with MgCl2, their adsorption capacities for CR were significantly increased over the entire pH range tested. The CR adsorption process by all biochars was best described with the pseudo-first order kinetics model, and the adsorption isotherm characteristics were better described with the Langmuir isotherm model for all biochars. The Langmuir maximum adsorption capacities for KB-Mg and PB-Mg were 423.0 mg/g and 394.7 mg/g, respectively. It is suggested that the main mechanism for CR adsorption on the Mg-biochars is electrostatic attraction between CR and the biochars.Conclusions : The results showed that surface modification with MgCl2 could greatly enhance the CR adsorption capacity of biochars, and the results demonstrated the great potential of KB-Mg and PB-Mg for CR removal.


2012 ◽  
Vol 441 ◽  
pp. 111-115 ◽  
Author(s):  
Lan Zhou ◽  
Jian Zhong Shao ◽  
Li Qin Chai ◽  
Guo Dong Fu

Sericin was investigated as modifier for surface modification on cotton fibers. The measurement of zeta potential was initially used to indicate the effectiveness of the modification. It was found that the sericin largely developed the positive charge on cotton fibers following a decrease in the pH. Adsorption studies of the annatto dye on the modified cotton fibers showed that sericin enhanced the adsorption capacity of the annatto dye on cotton fibers. The results of the zeta potential and the adsorption revealed that the uptake of annatto dye on modified cotton fibers occurred via electrostatic attractions between the anion of the dye and the cationic segments on the modified cotton fibers.


2018 ◽  
Vol 7 (4.7) ◽  
pp. 330 ◽  
Author(s):  
C. R. Girish ◽  
. .

The water contamination is an important crisis which is to be addressed in the recent time. The pollutants present in wastewater are treated by adsorption using activated carbon, which is considered as one of the effective method. The adsorbent has to be modified to improve the adsorption capacity and the surface properties. Various methods such as physical, chemical treatment, impregnation and functionalization techniques are available. Impregnation is one of the effective method carried out for surface modification and to increase the adsorption capacity. Therefore, current study investigates the different impregnation methods used for the surface modification of the adsorbent. It also reviews the various precursors used for adsorbent preparation, the impregnating agent, the operating conditions and the adsorption capacity of the adsorbent.  


2019 ◽  
Vol 26 (01) ◽  
pp. 1830006 ◽  
Author(s):  
MATHEUS PEGO ◽  
JANAÍNA CARVALHO ◽  
DAVID GUEDES

The main and new surface modification methods of activated carbon (AC) and their influence on application (adsorption capacity) were reviewed. Adsorption capacity is an important issue, contributing to hazardous substances environment management. According to literature, it is true that surface chemistry strongly affects adsorption capacity. Surface chemistry can be modified by several methods that lead to different activated carbon properties. Furthermore, adsorbate properties, and their relationships with surface structure, can impact adsorption properties. Surface modifications can be conducted by adding some atoms to the surface structure, making the surface more acidic or basic. Introduction of oxygen and ammonia atoms (chemical modification) are the main processes to make the surface more acidic and basic, respectively, although may bring chemical wastes to environment. Surface modification is done by chemical and physical modifications that lead activated carbons to present different properties. The main and new methods of chemical and physical modifications are compared and presented in this paper. Some new physical methods, like corona treatment, plasma discharge and microwave radiation, can be applied to cause surface modifications. Corona treatment can be a practical and new way to cause surface modification on an activated carbon surface.


2009 ◽  
Vol 620-622 ◽  
pp. 145-148
Author(s):  
Gyu Tae Seo ◽  
Jin Tae Kim ◽  
Sung Su Kim ◽  
Jutamas Kaewsuk

The objective of this study is to develop a novel powder activated carbon (PAC) by surface modification with magnetite nano-particles for enhanced removal of NOM in water. The PAC used for experiment was two types, SAC (wood-based) and MAC (coal-based). First the PAC was treated by heat at 650 or 900 °C for 1hr under N2. And then the PAC surface was synthesized with magnetite nano-particles at the same condition. Adsorption tests of NOM were carried out to identify functional characteristics of the surface modified. Despite reduced surface area, adsorption capacity of the surface modified PAC was comparable to the virgin one. However much increased adsorption capacity was obtained by heat treatment of the PACs. SEC and SUVA254 results showed no specific selectivity in removal of NOM by the modification of PAC surface characteristics. Enhanced oxidation of the NOM was also observed by the magnetite nano-particle synthetic PACs in contact with ozone. Conclusively the surface modification of the PAC has high potential as a novel adsorption material for advanced water treatment.


2021 ◽  
Author(s):  
Shiori Tanaka ◽  
Shingo Kanemura ◽  
Masaki Okumura ◽  
Kazuyuki Iwaikawa ◽  
Kenichi Funamoto ◽  
...  

Abstract Surface functionalization is a key process in rendering various materials biocompatible. Whereas a number of techniques and technologies have been developed for the purpose of biofunctionalization, plasma treatment enables highly efficient surface modification. Extending plasma treatment to biomolecules in the liquid phase will control biofunctionalization via a simple process. However, interactions between plasma discharge and biomolecules or solvents are poorly understood, potentially leading to the technical limitation as to the utility of plasma treatment. In this study, we developed a technology for substrate biofunctionalization that does not require surface modification but involves direct treatment of a collagen molecules with liquid-phase plasma discharge. Biofunctionalization of collagen by plasma treatment comprises three processes that increase its reactivity with hydrophobic substrates: (1) charge-dependent changes in surface and interfacial properties of the collagen solution; (2) local conformational changes of the collagen molecules without their global structural alterations; and (3) induction of a micelle-like association formed by collagen molecules. We anticipate such plasma-induced functionalization of protein molecules to provide a versatile technique in the applications of biomaterials, including those related to pharmaceuticals and cosmetics.


2018 ◽  
Vol 54 (4B) ◽  
pp. 19
Author(s):  
Hoa Thai Ma

Activated carbon (AC) has been proven to be an effective adsorbent for the removal of a variety of pollutants. AC is extensively used for adsorption because its high surface area is well-developed internal micro porosity. The objective of this study is to determine the optimal condition of the surface modification process of activated carbon from rice husk (ACRH) using HNO3. That increase the functional group, and improve affinity towards certain contaminants of ACRH for increasing the adsorption capacity of Ni2+ and Cd2+. Two factors were taken into account as: the concentration of HNO3 (1, 3, and 5 M), reaction time (1, 2, 3, 4 and 5 hours). The results showed that the optimal condition of the surface modification process was derived at the equilibrium concentration of HNO3 = 3 M and the equilibrium reaction time = 4 hour. Interestingly, in comparison with the control sample (ACRH not modified), the adsorption capacity of Ni2+ and Cd2+ increased from 10.0 to 17.2 mg/g and 10.4 to 29.6 mg/g, respectively. This adsorption capacity of modified ACRH shows the increase significantly.


Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3671 ◽  
Author(s):  
Michał Moritz ◽  
Małgorzata Geszke-Moritz

This study aimed at the adsorption of 18β-glycyrrhetinic acid (18β-GA), a pentacyclic triterpenoid derivative of oleanane type, onto functionalized mesoporous SBA-15 silica and non-porous silica (Aerosil®) as the reference adsorbent. Although 18β-GA possesses various beneficial pharmacological properties including antitumor, anti-inflammatory, and antioxidant activity, it occurs is small amounts in plant materials. Thus, the efficient methods of this bioactive compound enrichment from vegetable raw materials are currently studied. Siliceous adsorbents were functionalized while using various alkoxysilane derivatives, such as (3-aminopropyl)trimethoxysilane (APTMS), [3-(methylamino)propyl]trimethoxysilane (MAPTMS), (N,N-dimethylaminopropyl)trimethoxysilane (DMAPTMS), and [3-(2-aminothylamino)propyl] trimethoxysilane (AEAPTMS). The effect of silica surface modification with agents differing in the structure and the order of amine groups on the adsorption capacity of the adsorbent and adsorption efficiency were thoroughly examined. The equilibrium adsorption data were analyzed while using the Langmuir, Freundlich, Redlich-Peterson, Temkin, Dubinin-Radushkevich, and Dubinin-Astakhov isotherms. Both linear regression and nonlinear fitting analysis were employed in order to find the best-fitted model. The adsorption isotherms of 18β-GA onto silicas functionalized with APTMS, MAPTMS, and AEAPTMS indicate the Langmuir-type adsorption, whereas sorbents modified with DMAPTMS show the constant distribution of the adsorbate between the adsorbent and the solution regardless of silica type. The Dubinin-Astakhov, Dubinin-Radushkevich, and Redlich-Peterson equations described the best the process of 18β-GA adsorption onto SBA-15 and Aerosil® silicas that were functionalized with APTMS, MAPTMS, and AEAPTMS, regardless of the method that was used for the estimation of isotherm parameters. Based on nonlinear fitting analysis (Dubinin-Astakhov model), it can be concluded that SBA-15 sorbent that was modified with APTMS, MAPTMS, and AEAPTMS is characterized by twice the adsorption capacity (202.8–237.3 mg/g) as compared to functionalized non-porous silica (118.2–144.2 mg/g).


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