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 Physico-chemical surface characterization of a bacterial population isolated from a milking machine

2005 ◽  
Vol 22 (2-3) ◽  
pp. 247-251 ◽  
Author(s):  
Pilar Teixeira ◽  
Zulmira Lopes ◽  
Joana Azeredo ◽  
Rosário Oliveira ◽  
Maria João Vieira
Keyword(s):  
Surface Characterization ◽  
Bacterial Population ◽  
Chemical Surface ◽  
Physico Chemical ◽  
Milking Machine

Physico-chemical surface characterization of hyaluronic acid derivatives as a new class of biomaterials

1993 ◽  
Vol 4 (3) ◽  
pp. 245-273 ◽  
Author(s):  
R. Barbucci ◽  
A. Magnani ◽  
A. Baszkin ◽  
M.L. Da Costa ◽  
H. Bauser ◽  
...  
Keyword(s):  
Hyaluronic Acid ◽  
Surface Characterization ◽  
Chemical Surface ◽  
New Class ◽  
Physico Chemical

scholarly journals Influence of ALD Coating Layers on the Optical Properties of Nanoporous Alumina-Based Structures

Coatings ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 43 ◽  
Author(s):  
Ana Cuevas ◽  
María Martínez de Yuso ◽  
Víctor Vega ◽  
Ana González ◽  
Víctor Prida ◽  
...  
Keyword(s):  
Surface Characterization ◽  
Light Transmission ◽  
Single Layer ◽  
Geometrical Parameters ◽  
Optical Parameters ◽  
Xps Spectra ◽  
Nanoporous Alumina ◽  
Chemical Surface ◽  
Coating Layers

Optical changes associated with the surface coating of different metal oxides and nanolayers by the ALD technique of a nanoporous alumina structure (NPAS) obtained by the two-step anodization method were analyzed. The NPASs were coated with: (i) a single layer (SiO2 or TiO2), and (ii) a double layer of SiO2 plus Al2O3 or aluminum doped ZnO (AZO) to estimate the effect of surface layer coverage material, geometrical parameters (pore-size/porosity), and number of layers on light transmission/reflection. Chemical surface characterization of the different NPASs was carried out by analyzing XPS spectra, which allowed us to obtain an estimation of the coating layer homogeneity. Transmittance and spectroscopic ellipsometry measurements were analyzed in order to detect changes in characteristic optical parameters such as band gap, refractive index, and extinction coefficients associated with the material and the characteristics of the single or double coating layers.

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.

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