FTIR study on structural changes of different–rank coals caused by single/multiple extraction with cyclohexanone and NMP/CS 2 mixed solvent

Tian, Bin; Qiao, Yingyun; Tian, Yuanyu; Xie, Kui; Liu, Qing; Zhou, Haifeng

doi:10.1016/j.fuproc.2016.08.035

Cited by 73 publications

(31 citation statements)

References 58 publications

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“…The sample preparation work followed the procedure of Tian et al and Wang et al [71,72]. The characteristic peaks of the minerals and organic functional groups can be obtained from Figure 7d, indicating that there was a close relationship between the organic functional groups and B. licheniformis.…”

Section: Ftir Analysis Of the Minerals At A Mg/ca Molar Ratio Of 0 Anmentioning

confidence: 97%

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Extracellular and Intracellular Biomineralization Induced by Bacillus licheniformis DB1-9 at Different Mg/Ca Molar Ratios

et al. 2018

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Biomineralization has become a research hotspot and attracted widespread attention in the field of carbonate sedimentology. In this study, precipitation of carbonate minerals was induced by Bacillus licheniformis DB1-9 bacteria, (identity confirmed with its phylogenetic tree), to further explore the biomineralization mechanisms. During experiments, lasting up to 24 days with varying Mg/Ca molar ratios and regular monitoring of conditions, ammonia and carbonic anhydrase are released by the bacteria, resulting in a pH increase. Carbonic anhydrase could have promoted carbon dioxide hydration to produce bicarbonate and carbonate ions, and so promoted supersaturation to facilitate the precipitation of carbonate minerals. These include rhombohedral, dumbbell-shaped, and elongated calcite crystals; aragonite appears in the form of mineral aggregates. In addition, spheroidal and fusiform minerals are precipitated. FTIR results show there are organic functional groups, such as C–O–C and C=O, as well as the characteristic peaks of calcite and aragonite; these indicate that there is a close relationship between the bacteria and the minerals. Ultrathin slices of the bacteria analyzed by HRTEM, SAED, EDS, and STEM show that precipitate within the extracellular polymeric substances (EPS) has a poor crystal structure, and intracellular granular areas have no crystal structure. Fluorescence intensity and STEM results show that calcium ions can be transported from the outside to the inside of the cells. This study provides further insights to our understanding of biomineralization mechanisms induced by microorganisms.

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Section: Ftir Analysis Of the Minerals At A Mg/ca Molar Ratio Of 0 Anmentioning

confidence: 97%

“…FTIR Analysis of the Minerals at a Mg/Ca Molar Ratio of 0 and 3 Induced by BacteriaThe sample preparation work followed the procedure of Tian et al and Wang et al[71,72]. The characteristic peaks of the minerals and organic functional groups can be obtained fromFigure 7.…”

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confidence: 99%

Extracellular and Intracellular Biomineralization Induced by Bacillus licheniformis DB1-9 at Different Mg/Ca Molar Ratios

et al. 2018

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“…The organic functional groups on/within the minerals were analyzed by FTIR (Nicolet 380, Thermo Fisher Scientific Inc., Waltham, MA, USA) [77,78] using the potassium bromide method in a scanning range of 400-4000 cm −1 with a resolution of 4 cm −1 .…”

Section: Characterization Of the Extracellular Mineral Precipitatesmentioning

confidence: 99%

Mechanism of Biomineralization Induced by Bacillus subtilis J2 and Characteristics of the Biominerals

et al. 2019

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Biomineralization induced by microorganisms has become a hot spot in the field of carbonate sedimentology; however, the mechanisms involved still need to be explored. In this study, the bacterium Bacillus subtilis J2 (GenBank MG575432) was used to induce the precipitation of calcium carbonate minerals at Mg/Ca molar ratios of 0, 3, 6, 9, and 12. Bacillus subtilis J2 bacteria released ammonia to increase pH, but the ammonia released only made the pH increase to 8.25. Carbonic anhydrase was also produced to catalyze the hydration of carbon dioxide, and this process released carbonate and bicarbonate ions that not only increased pH but also elevated carbonate supersaturation. The biominerals formed at a Mg/Ca molar ratio of 0 were spherulitic, elongated, dumbbell-shaped, and irregularly rhombohedral calcite; at a Mg/Ca molar ratio of 3, the biominerals were calcite and aragonite, the weight ratio of calcite decreased from 26.7% to 15.6%, and that of aragonite increased from 73.3% to 84.4% with increasing incubation time. At higher Mg/Ca molar ratios, the biominerals were aragonite, and the crystallinity and thermal stability of aragonite decreased with increasing Mg/Ca molar ratios. FTIR results showed that many organic functional groups were present on/within the biominerals, such as C–O–C, N–H, C=O, O–H, and C–H. HRTEM-SAED examination of the ultra-thin slices of B. subtilis J2 bacteria showed that nano-sized minerals with poor crystal structure had grown or been adsorbed on the EPS coating. The EPS of the B. subtilis J2 strain contained abundant glutamic acid and aspartic acid, which could be deprotonated in an alkaline condition to adsorb Ca2+ and Mg2+ ions; this made EPS act as the nucleation sites. This study may provide some references for further understanding of the mechanism of biomineralization induced by microorganisms.

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“…It exhibited that HMD‐GO contained amino functional groups. The characteristic bands of GO appeared at 3,420 cm −1 (O‐H stretching vibration), 1,740 cm −1 (C = O stretching in carboxylic acid), 1,630 cm −1 (C = C stretching in aromatic ring), and 1,047 cm −1 (epoxy stretching vibration) . The reaction between GO and HMD was confirmed by the appearance of peaks at 2,836 and 2,911 cm −1 (C‐H stretching of CH 2 ) and a new peak at 1,560 cm −1 along with a broad band at 3,732 cm −1 (N‐H wagging vibration of the amine group) in FT‐IR spectra of HMD‐GO.…”

Section: Resultsmentioning

confidence: 87%

Improving the thermal conductivity and mechanical property of epoxy composites by introducing polyhedral oligomeric silsesquioxane‐grafted graphene oxide

Zhang

Song

et al. 2018

Polymer Composites

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In this work, polyhedral oligomeric silsesquioxane‐graphene oxide (POSS‐GO) was prepared by 1,6‐Hexanediamine (HDM) as a bridge and characterized using Fourier transform infrared spectroscopy, thermogravimetric analysis, X‐ray diffraction, and transmission electron microscope. High thermal conductivity toughening composites were prepared by introducing POSS‐GO into epoxy resin (EP) with solution blending. The introduction of HDM‐POSS molecular chain can not only improve the dispersion of GO in epoxy, but also as “stent” prevent the accumulation of GO. Results show that when the weight loading of GO and POSS‐GO was 1.0 phr, the thermal conductivity of composites improved by 26.32 and 63.16% as compared with neat epoxy. Impact strength of POSS‐GO/EP is 29.29% higher than that of GO/EP at 0.8phr and bending strength tests also showed similar results. When compared with pristine GO, POSS‐GO possessed better thermal conductivity and toughening effect for epoxy, moreover, the mechanism is discussed in this paper. POLYM. COMPOS., 39:E1890–E1899, 2018. © 2018 Society of Plastics Engineers

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FTIR study on structural changes of different–rank coals caused by single/multiple extraction with cyclohexanone and NMP/CS 2 mixed solvent

Cited by 73 publications

References 58 publications

Extracellular and Intracellular Biomineralization Induced by Bacillus licheniformis DB1-9 at Different Mg/Ca Molar Ratios

Extracellular and Intracellular Biomineralization Induced by Bacillus licheniformis DB1-9 at Different Mg/Ca Molar Ratios

Mechanism of Biomineralization Induced by Bacillus subtilis J2 and Characteristics of the Biominerals

Improving the thermal conductivity and mechanical property of epoxy composites by introducing polyhedral oligomeric silsesquioxane‐grafted graphene oxide

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