Preparation and ozone-surface modification of activated carbon. Thermal stability of oxygen surface groups

Jaramillo, J.; Álvarez, Pedro M.; Gómez-Serrano, V.

doi:10.1016/j.apsusc.2009.12.109

Cited by 62 publications

(24 citation statements)

References 22 publications

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“…Table 1 shows different contents of acidic and basic groups. It was observed that CAN and CAG1173 showed extreme values with basic group contents of 0.05 and 0.31 mol g −1 , respectively [32].…”

Section: Resultsmentioning

confidence: 99%

“…In Figure 5 the difference in the immersion enthalpy was related to the micropore volume. The other characteristic of the surface of an activated carbon that had a favorable influence on the energy interaction was the content of basic groups, since the thermal treatments carried out in this work increased the content of these groups due to the decomposition of the oxygenated groups that were removed from the surface and made it more hydrophobic, facilitating the interaction of non-polar solvents with the surface [32,38,39]. Figure 6 shows the relationship between ΔHim of activated carbons in cyclohexane and hexane and the content of total basic groups.…”

Section: Resultsmentioning

confidence: 99%

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Immersion Enthalpy of Activated Carbon–Cyclohexane and Activated Carbon–Hexane. Difference in the Solid–Liquid Interaction Enthalpy Due to the Structure of the Solvent

2019

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The enthalpy of immersion for five activated carbons (with different surface chemistry) in cyclohexane and hexane was determined in order to observe the intensity of the solid–liquid interaction. The enthalpy of immersion was related to the properties of activated carbons, such as micropore volume, total basic groups content, and the EoWo product, that characterized each solid-liquid system. The values for the immersion enthalpy were between −21.2 and −91.7 J g−1 for cyclohexane and between −16.4 and −66.1 J g−1 for hexane. It showed greater interaction between the cyclohexane and the activated carbons and it was related to the properties of this adsorbate, such as molecular size and molecular arrangement. The difference in the enthalpy of immersion between the solvents per unit of micropore volume for the set of activated carbons was calculated obtaining a value of −487 J cm−3.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Immersion Enthalpy of Activated Carbon–Cyclohexane and Activated Carbon–Hexane. Difference in the Solid–Liquid Interaction Enthalpy Due to the Structure of the Solvent

2019

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“…Data from the literature indicate the possibility of formation of various functional groups on the surface of activated carbon in the ozonation process: carboxylic, carbonyl, phenolic, lactonic groups [23][24][25]. Their elimination in the process of thermal treatment results in the formation of CO 2 from the carboxylic and lactonic groups or CO following the decomposition of the phenolic, quinonic, and etheric fractions [20,26]. Because of the different thermal stability of the functional groups, an approximate estimate of the character of these groups could be made, knowing that CO was the predominant product eliminated within the range of 500-800 • C. Figure 5c shows the existence of at least two types of functional groups, the first groups were thermally stable up to 490 • C, while the second groups remained present even up to 700 • C.…”

Section: Thermal Analysismentioning

confidence: 99%

Microbiological Properties of Microwave-Activated Carbons Impregnated with Enoxil and Nanoparticles of Ag and Se

Petuhov¹,

Lupaşcu

Behunova

et al. 2019

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Microwave-activated carbons from walnut shells (ACMW) were impregnated with Ag and Se nanoparticles and with the Enoxil biologically active preparation, and the microbiological properties of the obtained composites were studied. To increase the functionality of the adsorbent, the activated carbon was oxidized with ozone, resulting in ACMWO containing aliphatic and aromatic carboxylic groups. There was a considerable decrease in the specific surface of the activated carbon after the oxidation process. Nitrogen adsorption was used to determine the structural parameters of the activated carbons. A simultaneous thermal analysis was used to study the thermal behavior of intact and oxidized activated carbons. Infrared spectroscopy was applied to analyze the surface chemistry of the adsorbents. The microbiological activity of the activated carbons was studied using Escherichia coli bacteria and Candida albicans fungi. The kinetic study of the microbiological activity allowed the estimation of the bactericidal/fungicidal action time of the activated carbons.

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“…Although it is a consolidate material, activated carbons need to increase their adsorption capacity, especially for specific adsorbates, and this is possible by surface modifications on their chemical structure (Goscianska et al 2015). Surface modification can be carried out by chemical substances (Aguiar et al 2016, Yang et al 2016, ozone (Jaramillo et al 2010), nitration (Cao et al 2014, Shafeeyan et al 2015, physical methods (Ge et al 2015, Zhang et al 2016a), oxidation (Gong et al 2016, houshmand et al 2011) and other methods.…”

Section: Introductionmentioning

confidence: 99%

Surface modification of activated carbon by corona treatment

Pego

Bianchi

Carvalho

et al. 2019

An. Acad. Bras. Ciênc.

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Surface modification may lead activated carbon (AC) to take on different properties. This study aimed to promote surface modification of activated carbons using corona treatment (electrical discharge). In this study, powdered commercial activated carbon was used. Activated carbons were subjected to corona treatment at different exposure times (2, 5, 8 and 10 min) at 4.5 cm height from the source. To observe differences promoted by treatment, activated carbons were analyzed by acidity, surface functional groups, Fourier Transform Infrared Spectroscopy (FTIR), elemental analysis (ChN), proximate analysis and thermogravimetry. Corona treatment impacted surface chemistry of activated carbons. There was a trend of increasing surface acidity according to exposure time. There were changes in functional groups, increasing carboxyl acid and decreasing lactone and phenol groups. FTIR analysis showed peaks in the bands at 3500, 1650 and 1300 cm-1. Increase of oxygen content and decrease of carbon content were also found. Immediate analysis followed similar tendency for volatile and fixed carbon content. There were also differences in thermogravimetry analysis. Treated activated carbons were different compared to virgin activated carbon. This difference was performed by surface oxidation. Thus, this study showed that corona treatment caused surface modifications and might impact adsorption process.

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Preparation and ozone-surface modification of activated carbon. Thermal stability of oxygen surface groups

Cited by 62 publications

References 22 publications

Immersion Enthalpy of Activated Carbon–Cyclohexane and Activated Carbon–Hexane. Difference in the Solid–Liquid Interaction Enthalpy Due to the Structure of the Solvent

Immersion Enthalpy of Activated Carbon–Cyclohexane and Activated Carbon–Hexane. Difference in the Solid–Liquid Interaction Enthalpy Due to the Structure of the Solvent

Microbiological Properties of Microwave-Activated Carbons Impregnated with Enoxil and Nanoparticles of Ag and Se

Surface modification of activated carbon by corona treatment

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