Transformation of functional groups during lignite heat-treatment and its effects on moisture re-adsorption properties

2019 ◽  
Vol 192 ◽  
pp. 210-219 ◽  
Author(s):  
Fanjing Wei ◽  
Junjie Liao ◽  
Liping Chang ◽  
Yanna Han ◽  
Weiren Bao

In this work, we studied the physicochemical properties of thermally activated defecate at 650°C and studied their neutralizing and adsorption properties in the treatment of acidic wastewater. It was found that after heat treatment at 650°C the main functional groups of the defect, i.e. CaCO3 practical has not changed


2017 ◽  
Vol 19 (2) ◽  
pp. 181 ◽  
Author(s):  
Olzhas Kaipoldayev ◽  
Ye. Mukhametkarimov ◽  
Renata Nemkaeva ◽  
G. Baigarinova ◽  
Madi Aitzhanov ◽  
...  

Herein we show the effect of heat treatment of two dimensional layered titanium carbide structure (Ti3C2Tx), so called MXene. As prepared MXene has functional groups -OH, -F, -Cl. In order to remove the functional groups we heat treated the MXene in Ar (with 0.01% O2) and H2 (with 0.01% H2O) atmospheres. We discovered the significant decrease in the amount of functional groups (-F and -Cl) and increase in the -O content, which refers to the oxidation of the material. Also we determined the optimal regime for Raman spectroscopy in order to avoid any changes in the structure of the material. We revealed that titanium carbide changes its structure at 700 °C and 900 °C into two different titanium dioxide modifications like rutile and anatase in Ar (with 0.01% O2) atmosphere. Also there are small changes occurred in Ti3C2Tx structure and formation of amorphous carbon after 700 °C treatment in H2 (with 0.01% H2O) atmosphere and formation of TiO2 (rutile) at 900 °C. Energydispersive X-ray spectroscopy (EDX) revealed the reduction of functional groups at 700 °C in both atmospheres and total disappearance of –F and –Cl and increasing the oxygen at 900 °C. The huge increase of oxygen by atomic percent, can be explained by the initial oxygen content in argon and hydrogen gases.


2019 ◽  
Vol 2019 ◽  
pp. 1-18 ◽  
Author(s):  
Dun Wu ◽  
Wenyong Zhang

Owing to the complexity and heterogeneity of coal during pyrolysis, the ex situ analytical techniques cannot accurately reflect the real coal pyrolysis process. In this study, according to the joint investigation of Fourier-transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), the structural evolution characteristics of lignite-subbituminous coal-bituminous coal-anthracite series under heat treatment were discussed in depth. The results of the infrared spectrum of coal show that the different functional groups of coal show different changes with the increase of coal rank before pyrolysis experiment. Based on in situ infrared spectroscopy experiments, it was found that the infrared spectrum curves of the same coal sample have obvious changes at different pyrolysis temperatures. As a whole, when the pyrolysis temperature is between 400 and 500°C, the coal structure can be greatly changed. By fitting the infrared spectrum curve, the infrared spectrum parameters of coal were obtained. With the change of temperature, these parameters show regular changes in coal with different ranks. In the XRD study of coal, the absorption intensity of the diffraction peak (002) of coal increases with increasing coal rank. The XRD patterns of coal have different characteristics at different pyrolysis temperatures. Overall, the area of (002) diffraction peak of the same coal sample increases obviously with the increase of temperature. The XRD structural parameter of coal was obtained by using the curve fitting method. The changing process of two parameters (interlayer spacing (d002) and stacking height (Lc)) can be divided into two main stages, but the average lateral size (La) does not change significantly and remains at the 2.98 ± 0.09 nm. In summary, the above two technologies complement each other in the study of coal structure. The temperature range of both experiments is different, but the XRD parameters of coal with different ranks are reduced within the temperature range of less than 500°C, which reflects that the size of coal-heated aromatic ring lamellae is reduced and the distance between lamellae is also reduced, indicating that the degree of condensation of coal aromatic nuclei may be increased. Correspondingly, the FTIR parameters of coal also reflect that, with increasing temperature, the side chains of coal are constantly cracked, the oxygen-containing functional groups are reduced, and the degree of aromatization of coal may be increased.


Carbon ◽  
2008 ◽  
Vol 46 (15) ◽  
pp. 2096-2106 ◽  
Author(s):  
Montserrat R. Cuervo ◽  
Esther Asedegbega-Nieto ◽  
Eva Díaz ◽  
Salvador Ordóñez ◽  
Aurelio Vega ◽  
...  

1997 ◽  
Vol 46 (3) ◽  
pp. 431-436 ◽  
Author(s):  
T. M. Roshchina ◽  
V. Ya. Davydov ◽  
K. B. Gurevich ◽  
A. A. Mandrugin ◽  
N. M. Khrustaleva

2021 ◽  
Vol 1036 ◽  
pp. 137-144
Author(s):  
Zhi Bo Sheng ◽  
Chen Kang Wang ◽  
Ling Zheng Wu ◽  
Wen Liang Jin ◽  
Shen You Song Jin

The graphene-based composites was prepared by the oxidation of graphene nano-platelets. The characterization results of thermogravimetric analysis (TGA) and Fourier transform infrared spectrum (FT-IR) indicated that acid treatment can generate abundant functional groups on the surface of graphene. The determined equilibrium adsorption capacity of FGN for lead was 57.765 mg/g, which is higher than that of many currently reports. The adsorption process was completed within 40 min and the adsorption isotherms confirmed to Langmuir classical isotherms models.


2020 ◽  
pp. 096739112096843
Author(s):  
Shih-Hang Chang ◽  
Ming-Han Hsieh

In this study, we firstly investigated the surface and protein adsorption properties of montmorillonite (MMT)/chitosan (CS) composite films with various MMT/CS weight ratios for metallic implants coating applications. Bicinchoninic acid (BCA) protein assay results show that the neat CS film exhibits a high concentration of bovine serum albumin (BSA) protein adhesion because the abundant carbonyl and amide functional groups on the surface of the CS film easily form hydrogen bonds with the copious carboxylic acid groups on the surface of the BSA protein. The MMT/CS composite films with MMT/CS = 3, 5, 8, and 10 possess a much lower BSA adhesion concentration than that of the neat CS film, as some of the carbonyl and amide functional groups on the surface of the composite films are replaced by the –Si–O–Si and –Al–O–Al groups. Among these MMT/CS composite films, the film with MMT/CS = 5 exhibits the lowest BSA adsorption concentration because it possesses a higher MMT content than those with MMT/CS = 1 and 3 and a smoother and non-porous surface than those with MMT/CS = 8 and 10. According to our results, MMT/CS composite films with appropriate MMT/CS weight ratios exhibit better surface and protein adsorption properties than neat CS for biomedical applications.


2020 ◽  
Vol 981 ◽  
pp. 98-103
Author(s):  
Mona Alis Md. Yasser ◽  
Zaidi Embong ◽  
Erween Abdul Rahim ◽  
Amiril Sahab Abdullah Sani ◽  
Kamaruddin Kamdani

This study was conducted to investigate the efficiency of Minimum Quantity Lubrication (MQL) technique by using Modified Jatropha Oil (MJO) bio-based lubricant with the presence of 10% Ammonium Ionic Liquid (MJO+AIL10%) and 1% Phosphonium Ionic Liquid (MJO+PIL1%) additives respectively at various temperature of 200 °C, 300 °C and 400 °C heat treatment to determine the ability to exhibit corrosion and wear throughout the process. Fourier-Transform Infrared Spectroscopy (FTIR) analysis revealed prominent peaks of functional groups in these bio-lubricants; esters (C-O) and (C=O), alkanes (C-H), hydroxide (O-H), and nitrile groups deposited on the cutting tool surface. Initially, nitrile group is detected on cutting tool surface without lubricants at 2200 to 2300 absorption band reduced to lower intensity and most likely concealed by MJO+AIL10% compared to MJO+PIL1% where the nitrile group remains reflected in FTIR spectrum. In this work, it is proved that MJO+AIL10% has higher viscosity as compared to MJO+PIL1%. in the context of functional groups and supported the previous study on MJO+AIL10% as corrosion inhibitor.


2015 ◽  
Vol 44 (16) ◽  
pp. 7419-7427 ◽  
Author(s):  
Wanjun Mu ◽  
Mei Li ◽  
Xingliang Li ◽  
Zongping Ma ◽  
Rui Zhang ◽  
...  

The hexagonal WO3 nanowires prepared with the assistance of C2H10N·H2SO4 possess a large specific surface area and numerous adsorption functional groups, consequently improving the Sr2+ adsorption capacity considerably.


Sign in / Sign up

Export Citation Format

Share Document