HIGH ENTROPY ALLOWS A BETTER AFFINITY BETWEEN METAL IONS AND ACTIVATED CARBON FIBRES

Recent numerical approaches to extracting metal species using carbonaceous materials have de facto stimulated an interest in the field of microextraction, but theoretical observations inspired by randomness changes have been elusive. In this contribution, we present the degree of randomness using Cu (II) and Pb (II). Here, activated carbon fibres were employed as the skeleton adsorbent, providing scientific insights via the aqueous phase. Coupled isotherms of Langmuir and Freundlich were represented to unravel the aforementioned thermodynamics. Findings revealed that the Langmuir isotherm best described the equilibrium state and the trend was in accordance with the energy computation. The maximum microextraction performance was 84.75 mg/g and 102.04 mg/g for Cu (II) and Pb (II), respectively. Under all circumstances, there was a high randomness change as the microextraction performance increased.

The Use of Single-Sided NMR to Study Moisture Behaviour in an Activated Carbon Fibre/Phenolic Composite

Nuclear Magnetic Resonance (NMR) has been shown to be a useful technique to study the form and content of water in polymer composites. Composites using activated carbon fibres with phenolic resin have complex water absorption behaviour which would benefit from such investigation; however, the presence of the conductive fibres can make NMR problematic. In this study, single-sided NMR has been successfully used on such material by developing a method for sample-to-sample compensation for the effect of conductivity. Transverse relaxation curves showed water to be primarily in two states in the resin, corresponding to "bound" and "mobile" molecules. In addition, two much less bound states were identified in the composite, associated firstly with water adsorbed on to the fibre surface and secondly with clusters of water molecules moving more freely within the fibre pores.

Sisal xylem fibre-based activated carbon fibres for fuel adsorption: effect of thermal stabilization of diammonium phosphate

Activated carbon fibres (ACFs) are considered as the next generation of activated carbon products. However, lack of structural diversity in pore structure and high prices of raw materials for ACFs has restrained the development of ACF materials. In this paper, a sisal-based activated carbon fibre (SACF) material was prepared from sisal wastes with a unique thermal stabilization treatment to maintain fibrous shapes of SACFs while dispersing in solutions, and the SACFs were prepared as raw fibre materials for fuel evaporation emissions controlling products. Experimental results of N 2 adsorption showed that SACF has a typical I-type adsorption isotherm, with specific surface area of SACF samples of approximately 1200 m 2 g −1 , and mainly microporous pore structure. Compared with commercial samples (specific surface area, 1841.29 m 2 g −1 ), the butane working capacities of SACF for advanced fuel evaporation emissions controlling product was 0.4 g/100 ml higher. Furthermore, two dynamic models, Thomas model and Clark model, were applied to adsorption breakthrough data, which showed excellent fit. And it indicated from the adsorption breakthrough curves and parameters of both models that the SACF has better performance in fuel adsorption and desorption process than the commercial samples.

Correlations Between Alkali and Crystallinity in lyocell-Based ACF Probed with X-Ray Diffraction

This study examined the effect of alkalis on lyocell-based activated carbon fibres (ACFs) with high Brunauer-Emmett-Teller (BET) surface areas, using X-ray diffraction (XRD). Here, alkali treatments were conducted using 10 ~ 25 % NaOH and KOH on lyocell samples for 3 h at ambient room temperature. A secondary treatment with 4 % each of KOH and H3PO4 for an additional 3 h followed. An activated form of the samples was prepared by oxidation (stabilisation), carbonisation, and activation. The final ACF form of the samples showed a porous structure with high BET surface areas (> 1,000 m² g^-1). A 25 % dosage of NaOH produced the highest BET surface area compared to other samples. In terms of crystallinity, a 15 % dosage of KOH was found to be the optimum dosage to secure the highest degree of crystallinity among all samples. Meanwhile, the NaOH was successfully shifted the samples into the most distinct form of cellulose II. 15 % NaOH was found to secure the most stable thermal characteristics, as determined via thermo-gravimetric analysis. The present work demonstrates the various physio-chemistries of ACFs prepared with different proportions and types of alkalis, leading to intriguing potential applications.