scholarly journals The Role of Surface Chemistry and Polyethylenimine Grafting in the Removal of Cr (VI) by Activated Carbons from Cashew Nut Shells

2021 ◽  
Vol 7 (1) ◽  
pp. 27
Author(s):  
Victoria A. Smith ◽  
Juster F. A. Rivera ◽  
Ruby Bello ◽  
Elena Rodríguez-Aguado ◽  
Mohammed R. Elshaer ◽  
...  
Keyword(s):  
Surface Characterization ◽  
Activated Carbons ◽  
Carbon Surface ◽  
Maximum Efficiency ◽  
Cashew Nut ◽  
Average Maximum ◽  
Carboxylic Groups ◽  
Positively Charged

Activated carbons prepared from cashew nut shells and modified by grafting polyethylenimine onto the surface were tested for removal of Cr (VI). The removal efficiency of carbons without and with polyethylenimine decreased with an increase in pH, with maximum efficiency found at pH 2. The average maximum adsorption capacities of carbons were calculated to be 340 ± 20 mg/g and 320 ± 20 mg/g for unmodified and modified carbons, respectively. Surface characterization of carbons revealed that C–O functionalities are actively involved in both polyethylenimine grafting and Cr (VI) removal. Moreover, lactone groups and amides, formed by polyethylenimine grafting, seemingly undergo acid hydrolysis with formation of phenol and carboxylic groups. Considering that Cr (III) is the only form of chromium found on the surface of both carbons, the reduction mechanism is deduced as the predominant one. Here Cr (VI), majorly present as HCrO4¯, is attracted to the positively charged carbon surface, reduced to Cr (III) by phenol groups, and adsorbed inside the pores. The mechanism of Cr (VI) removal appears to be similar for unmodified and modified carbons, where the smaller adsorption capacity of the latter one can be related to steric hindrance and pore inaccessibility.

Acceleration of the healing process of full-thickness wounds using hydrophilic chitosan–silica hybrid sponge in a porcine model

2018 ◽  
Vol 32 (8) ◽  
pp. 1011-1023 ◽  
Author(s):  
Ji-Ung Park ◽  
Seol-Ha Jeong ◽  
Eun-Ho Song ◽  
Juha Song ◽  
Hyoun-Ee Kim ◽  
...  
Keyword(s):  
Wound Healing ◽  
Surface Characterization ◽  
Porcine Model ◽  
Healing Process ◽  
Synergetic Effect ◽  
Wound Healing Process ◽  
Cutaneous Wounds ◽  
Chemical Coupling

In this study, we evaluated the surface characterization of a novel chitosan–silica hybridized membrane and highlighted the substantial role of silica in the wound environment. The chemical coupling of chitosan and silica resulted in a more condensed network compared with pure chitosan, which was eventually able to stably maintain its framework, particularly in the wet state. In addition, we closely observed the wound-healing process along with the surface interaction between chitosan–silica and the wound site using large-surface-area wounds in a porcine model. Our evidence indicates that chitosan–silica exerts a synergetic effect of both materials to promote a remarkable wound-healing process. In particular, the silica in chitosan–silica accelerated wound closure including wound contraction, and re-epithelialization via enhancement of cell recruitment, epidermal maturity, neovascularization, and granulation tissue formation compared with pure chitosan and other commercial dressing materials. This advanced wound dressing material may lead to effective treatment for problematic cutaneous wounds and can be further applied for human skin regeneration.

scholarly journals Surface Characterization of Virulent Treponema pallidum

1980 ◽  
Vol 30 (3) ◽  
pp. 814-823 ◽  
Author(s):  
John F. Alderete ◽  
Joel B. Baseman
Keyword(s):  
Surface Characterization ◽  
Outer Membrane Proteins ◽  
Treponema Pallidum ◽  
Peritoneal Macrophages ◽  
Indicator System ◽  
Surface Proteins ◽  
Molecular Organization ◽  
Testicular Cells

Characterization of the surface of Treponema pallidum was accomplished by [ 125 I]lactoperoxidase-catalyzed iodination of intact organisms and sensitive radioimmunoprecipitation and gel electrophoresis technology. At least 11 outer membrane proteins with molecular weights ranging from 89,000 (89K) to 20K were identified, and all elicited high titers of antibody in experimentally infected rabbits. Proteins of 89.5K, 29.5K, and 25.5K previously implicated as ligands involved in attachment (J. B. Baseman and E. C. Hayes, J. Exp. Med. 151: 573-586, 1980) were found to reside on the treponemal surface. Low levels of the 89.5K treponemal protein were released by high salt concentrations, whereas the remaining comigrating material was neither radioiodinated nor released with selective detergents. Other lower-molecular-weight (60K, 45K, and 30K) surface proteins were extracted with octyl glucoside detergent, suggesting their hydrophobic interaction with the external membrane. The molecular organization of surface proteins was studied by employing the cross-linker dithiobis(succinimidyl)-propionate, and data suggested the presence of a highly fluid envelope resulting in random collisions by the surface proteins. The biological function of the treponemal outer envelope proteins was evaluated using, as the indicator system, adherence of T. pallidum to monolayer cultures of eucaryotic cells. Trypsin treatment of motile, freshly harvested organisms decreased the extent of surface parasitism to normal rabbit testicular cells, reinforcing the idea of the proteinaceous nature and role of treponemal ligands for attachment. Other data supported functional and antigenic relatedness among the implicated ligands. Finally, brief periodate treatment of human epithelial (HEp-2) and normal rat testicular cells as well as casein-elicited rabbit peritoneal macrophages significantly reduced the extent of treponemal parasitism, suggesting a role of specific host membrane molecules as mediators of attachment.

Development and surface characterization of positively charged filters

2005 ◽  
Vol 40 (17) ◽  
pp. 4531-4539 ◽  
Author(s):  
N. Kattamuri ◽  
J. H. Shin ◽  
B. Kang ◽  
C. G. Lee ◽  
J. K. Lee ◽  
...  
Keyword(s):  
Surface Characterization ◽  
Positively Charged

Chemical Surface Characterization of Activated Carbons by Adsorption Excess of Probe Molecules

2016 ◽  
Vol 39 (6) ◽  
pp. 1144-1150 ◽  
Author(s):  
Julian Treese ◽  
Christoph Pasel ◽  
Michael Luckas ◽  
Dieter Bathen
Keyword(s):  
Surface Characterization ◽  
Activated Carbons ◽  
Probe Molecules ◽  
Chemical Surface

scholarly journals Preparation and Characterization of Activated Carbon Obtained from Water Treatment Plant Sludge for Removal of Cationic Dye from Wastewater

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1549
Author(s):  
Alaor Valério Filho ◽  
Raíssa Xavaré Kulman ◽  
Luana Vaz Tholozan ◽  
André Ricardo Felkl de Almeida ◽  
Gabriela Silveira da Rosa
Keyword(s):  
Water Treatment ◽  
Activated Carbons ◽  
Chemical Activation ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Mesoporous Structure ◽  
Carboxylic Groups ◽  
In The Beginning ◽  
Water Treatment Plant Sludge

The proposal of this work was the preparation and characterization of activated carbons obtained from water treatment plant sludge (WTS) to apply as adsorbents in the removal of organic dye contaminants from wastewater. The activated carbons were produced with a combination of chemical activation and pyrolysis processes. The textural characteristics of both adsorbents presented a satisfactory superficial area and mesoporous structure. The presence of phenolic and carboxylic groups in the surface indicated a better adsorption of cationic adsorbates. When applied as adsorbents in the removal of methylene blue (MB) from wastewater, the maximum removal values obtained were up to 96%. The adsorption results showed that the adsorption was faster in the beginning and reached maximum around 30 min. The Elovich kinetic model and the Sips isotherm model presented the best fit to experimental data, which was checked by analysis of variance (ANOVA). The production of activated carbons from WTS is a sustainable and effective option in the removal of MB dye.

scholarly journals The Role of Observation–Measurement Methods in the Surface Characterization of X39Cr13 Stainless-Steel Cutting Blades Used in the Fish Processing Industry

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5796
Author(s):  
Wojciech Kapłonek ◽  
Krzysztof Nadolny ◽  
Bartosz Zieliński ◽  
Jarosław Plichta ◽  
Danil Pimenov ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Surface Characterization ◽  
Measurement Methods ◽  
Numerical Control ◽  
Regeneration Process ◽  
Fish Processing ◽  
Processing Industry ◽  
Five Axis

In the modern fish processing industry, flat fishes play an important role. They are processed into a final product in the form of a fillet during the skinning operation, which is carried out on machines operating in automated production lines. These machines are usually equipped with a single planar cutting blade or a few of such blades. The high-efficiency skinning and industrial conditions cause rapid wear of the cutting edge of the blade, which is detrimental to the quality of the final product. One of the forms of renewing the cutting ability of these types of tools is the regeneration carried out with the use of precise traverse surface grinding. The results of this process must be carefully verified for determining its correctness and possible optimization of its parameters. The main goal of this article was to characterize the usefulness of a number of observational and measuring methods to evaluate the results of the technical blade regeneration process. In this work, a number of contemporary observation–measurement methods such as optical microscopy (OM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), optical profilometry (OP), and angle-resolved scattering (ARS), supported by image processing and analysis techniques, were analyzed. The authors focused on presenting the role of the abovementioned methods in the surface characterization of planar cutting blades made of X39Cr13 chromium martensitic stainless steel before and after the technological operation of flat-fish skinning. Additionally, the surface condition after the regeneration process carried out using the five-axis CNC (computerized numerical control) grinding machine was also assessed. Numerous results of surface observations, elemental composition microanalysis, high-accuracy surface microgeometry measurements, and quantitative and qualitative analysis confirming the possibility of using the proposed methods in the presented applications are presented.

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