Exploring the effect of oxygen-containing functional groups on the water-holding capacity of lignite

Liu, Jie; Jiang, Xiangang; Cao, Yu; Zhang, Chen; Zhao, Guangyao; Zhao, Maoshuang; Li, Feng

doi:10.1007/s00894-018-3653-4

Cited by 17 publications

(8 citation statements)

References 51 publications

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“…Molecular simulation of the adsorption of some water molecules into porous carbon materials − can be found in literature. Feng et al − used carbon nanotubes, graphene oxide, and small molecules with different OFGs as lignite monomers to investigate the interaction between OFG and water ( n H 2 O@OFG) and found that the interaction energy between water and carboxyl molecules ( n H 2 O@carboxyl) was the largest, followed by the interaction with phenolic hydroxyl, carbonyl, and benzene, which was similar to the results obtained by Wu et al (interaction of 1H 2 O@OFG carboxyl > phenolic hydroxyl > carbonyl > alcoholic hydroxyl > ether). Wu et al also accurately demonstrated the hydrogen bonds (HB), van der Waals interactions, and steric repulsion by reduced density gradient isosurface.…”

Section: Introductionsupporting

confidence: 65%

Water Clusters in Lignite and Desorption Energy Calculation by Density Functional Theory

He¹,

Xiao²,

Miao³

et al. 2019

ACS Omega

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The interaction of water and hydrophilic sites with hydroxyl, carboxyl, and multiple oxygen-containing functional groups (OFGs) in lignite molecules was studied by density functional theory. The adsorption of water molecules on the lignite surface initially resulted in the formation of hydrogen bond-driven stable rings by three to four water molecules, followed by the formation of three-dimensional water clusters like a ″patchwork″. Aqueous layer thickness obtained from the water cluster size was 0.4–0.6 nm, which was consistent with the experimental data. Thus, pore-filling water beyond this range was less affected by the OFGs on the surface. Calculation of the adsorption energy predicts that the water clusters were primarily formed in the hydrophilic sites with three OFGs (site 1, including a carbonyl group, an alcoholic hydroxyl group and an etheroxy group in tetrahydropyran), then in COOH, and in O–H. For isolated hydroxyl groups, the interaction between the hydroxyl group and water molecules was weaker than that between the water molecules. When the water cluster was located at the hydrophilic sites with two or more OFGs, the adsorption energy of lignite–water interaction was higher than that of water–water interaction. Investigating the thermodynamics of the adsorption process at a molecular scale will help in understanding both drying and resorption process of dried lignite during industrial production.

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Section: Introductionsupporting

confidence: 65%

Water Clusters in Lignite and Desorption Energy Calculation by Density Functional Theory

He¹,

Xiao²,

Miao³

et al. 2019

ACS Omega

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“…The SDF has a certain degree of water absorption capacity, which can increase the WHC. The increase in SDF content (6.91–20.82% versus 2.61–5.86%) caused an increase in the WHC of bran, which may be due to the exposure of hydroxyl and carboxyl groups to water molecules as a result of the instantaneous shear stress from SE 31 . SE bran had significantly higher SC than native bran did ( α = 0.01) (Table 2).…”

Section: Discussionmentioning

confidence: 97%

“…The increase in SDF content (6.91-20.82% versus 2.61-5.86%) caused an increase in the WHC of bran, which may be due to the exposure of hydroxyl and carboxyl groups to water molecules as a result of the instantaneous shear stress from SE. 31 SE bran had significantly higher SC than native bran did (⊍ = 0.01) (Table 2). The observed results are consistent with the finding of a recent study, 24 which may be due to the increase in the number of short chains and surface area of SDF due to SE.…”

Section: Effect Of Se Pressure On Functional Properties Of Wheat Branmentioning

confidence: 94%

Effects of steam explosion on the nutritional and functional properties of black‐grained wheat bran and its application

et al. 2023

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Background In recent years, an increasing interest in healthy functional foods has been documented among health‐conscious consumers. Steam explosion (SE)‐treated black‐grained wheat (BGW) bran was explored for the development of chiffon cakes with high nutritional and functional value. Results The content of crude fat and total starch decreased with increasing SE pressure, whereas water‐holding capacity and antioxidant activity increased, suggesting SE at 0.6–1.0 MPa could be an effective technique for enhancing the nutritional and functional properties of wheat bran. The protein, iron, zinc, manganese, selenium, and soluble dietary fiber contents, the water‐holding, oil‐binding, swelling, cholesterol binding, and cation‐exchange capacities, and antioxidant activity of SE BGW bran were better than those of SE white‐grained wheat bran. The addition of SE bran (0.8 MPa) to flour significantly decreased the peak viscosity, final viscosity, and setback and increased the pasting temperature. The effect of SE bran on the pasting properties of low‐gluten and medium‐gluten flour was stronger than that of high‐gluten flour. SE BGW bran altered the physicochemical properties of chiffon cakes. When 6% SE BGW bran (0.8 MPa) was added, chiffon cakes exhibited good specific volume, hardness, chewiness, and other sensory qualities. Conclusions These results indicate that SE at 0.6–1.0 MPa is an effective technique for enhancing the nutritional and functional properties of wheat bran. SE BGW bran can be alternatives to food materials for developing health functional cereal‐based products. © 2022 Society of Chemical Industry.

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“…The adsorption of water is associated with not only the pore characteristics of coal but also the number of oxygen-containing functional groups in coal. 78,79 As shown in Figure 12F, the low-rank coal sample YZG2 has a greater equilibrium moisture content, which is mainly due to the existence of a large amount of oxygen-containing functional groups in the low-rank coal. Conversely, the medium-and high-rank coals have few oxygen-containing functional groups, so their water-holding capacity is mainly influenced by the pore structure of the coal.…”

Section: Relationship Between the Fractal Dimension And Adsorption mentioning

confidence: 99%

Investigation of the fractal characteristics of adsorption‐pores and their impact on the methane adsorption capacity of various rank coals via N₂ and H₂O adsorption methods

Chen

Yang

Gao

et al. 2020

Energy Science & Engineering

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Coal seam is a sedimentary body with complex pore system. The gas adsorption property of coal is greatly determined by the adsorption‐pores (<100 nm), and the fractal dimension can be used an index to estimate the impact of the adsorption‐pores on the methane adsorption capacity of various rank coals. In this paper, low‐temperature N2 adsorption and H2O adsorption methods were used to study the adsorption‐pores structure and its fractal features. The results show that the development of adsorption‐pores closely depends on the coalification, and the degree of pore development exhibits a U‐shaped trend with increasing coal rank. Additionally, the pore size distributions of coal samples from N2 adsorption analysis and H2O adsorption analysis are similar, especially for samples LH7 and WLH8. Fractal analysis indicates that D2(N2) (0.5 < P/P0 < 1) can more accurately characterize the fractal features of adsorption‐pores than D2(H2O), which may be a result of the significant coal‐H2O interaction. Moreover, D2(N2) has stronger correlations with the coal pore parameters. With the increase in D2(N2), the Langmuir volume first decreases and then increases, which is probably associated with the competition effect of the pore structure and surface irregularity of coal. When D2(N2) < 2.7‐2.8, the pore structure plays a key role, while for D2(N2) > 2.7‐2.8, the influence of the specific surface area is more prominent. The equilibrium moisture content of the coal samples also has a positive correlation with D2, except for low‐rank coal sample YZG2 due to the presence of a large amount of oxygen‐containing functional groups, which increases its water‐holding capacity.

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Exploring the effect of oxygen-containing functional groups on the water-holding capacity of lignite

Cited by 17 publications

References 51 publications

Water Clusters in Lignite and Desorption Energy Calculation by Density Functional Theory

Water Clusters in Lignite and Desorption Energy Calculation by Density Functional Theory

Effects of steam explosion on the nutritional and functional properties of black‐grained wheat bran and its application

Investigation of the fractal characteristics of adsorption‐pores and their impact on the methane adsorption capacity of various rank coals via N₂ and H₂O adsorption methods

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Exploring the effect of oxygen-containing functional groups on the water-holding capacity of lignite

Cited by 17 publications

References 51 publications

Water Clusters in Lignite and Desorption Energy Calculation by Density Functional Theory

Water Clusters in Lignite and Desorption Energy Calculation by Density Functional Theory

Effects of steam explosion on the nutritional and functional properties of black‐grained wheat bran and its application

Investigation of the fractal characteristics of adsorption‐pores and their impact on the methane adsorption capacity of various rank coals via N2 and H2O adsorption methods

Contact Info

Product

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About

Investigation of the fractal characteristics of adsorption‐pores and their impact on the methane adsorption capacity of various rank coals via N₂ and H₂O adsorption methods