Pub Date : 2024-11-29DOI: 10.1016/j.clay.2024.107646
Chao Xu , Xingqing Zhao , Huaiyu Duan , Wei Gu , Du Zhang , Rucheng Wang , Xiancai Lu
Direct contact of bacteria with minerals can provide better leaching effect than indirect contact in the process of bioleaching. As a leaching assistant, surfactant can change the surface tension of ore leaching solution, improve the bacterial adsorption capacity and enhance the biological leaching effect. Thus, this study investigated the mechanisms by which chemical and biological surfactants influence bacterial metabolism, bacterial adsorption, and leaching in the bioleaching process of lepidolite. With the addition of the biosurfactant rhamnolipid and chemical surfactants sodium dodecyl sulfate and Tween-20, FTIR of leaching residues indicated that non-polar functional groups appeared, and the contact angles decreased from 75.22° to 10.64°, 6.8°, 43.18°. Surfactants reduced the surface tension at the solid-liquid interface through the combined action of their hydrophilic head groups and hydrophobic tail groups, thereby increasing the contact area and adsorption efficiency between bacteria and minerals. Additionally, surfactants weaken the chemical bonds of mineral metals and promote the complexation of -COOH and -OH groups in organic acids with minerals. Surfactants-assisted bacterial attachment altered mineral lattice structure via microenvironment creation and bacterial metabolized organic acids.
{"title":"Mechanism of surfactant effect on bacterial adsorption during bioleaching of lepidolite","authors":"Chao Xu , Xingqing Zhao , Huaiyu Duan , Wei Gu , Du Zhang , Rucheng Wang , Xiancai Lu","doi":"10.1016/j.clay.2024.107646","DOIUrl":"10.1016/j.clay.2024.107646","url":null,"abstract":"<div><div>Direct contact of bacteria with minerals can provide better leaching effect than indirect contact in the process of bioleaching. As a leaching assistant, surfactant can change the surface tension of ore leaching solution, improve the bacterial adsorption capacity and enhance the biological leaching effect. Thus, this study investigated the mechanisms by which chemical and biological surfactants influence bacterial metabolism, bacterial adsorption, and leaching in the bioleaching process of lepidolite. With the addition of the biosurfactant rhamnolipid and chemical surfactants sodium dodecyl sulfate and Tween-20, FTIR of leaching residues indicated that non-polar functional groups appeared, and the contact angles decreased from 75.22° to 10.64°, 6.8°, 43.18°. Surfactants reduced the surface tension at the solid-liquid interface through the combined action of their hydrophilic head groups and hydrophobic tail groups, thereby increasing the contact area and adsorption efficiency between bacteria and minerals. Additionally, surfactants weaken the chemical bonds of mineral metals and promote the complexation of -COOH and -OH groups in organic acids with minerals. Surfactants-assisted bacterial attachment altered mineral lattice structure via microenvironment creation and bacterial metabolized organic acids.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"264 ","pages":"Article 107646"},"PeriodicalIF":5.3,"publicationDate":"2024-11-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142747505","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-26DOI: 10.1016/j.clay.2024.107644
Anbei Deng , Qian Fang , Qile Geng , Hanlie Hong , Lulu Zhao , Chen Liu , Xiaoliang Cai , Yiming Wang
Clay mineralogy and geochemical characteristics of two soil profiles developed on intrusive (quartz monzonite) and extrusive (rhyolite) rocks in subtropical China were investigated to reveal clay mineralogical responses to weathering of different parent rocks under a subtropical climate. Overall chemical weathering intensity and biotic weathering intensity do not show significant differences between the two profiles, suggesting that the difference in parent lithology and rock's cooling history did not exert a significant control on weathering intensity. The differences between two profiles are mainly reflected in clay mineralogy and evolution of elemental loss/gain. The soil developed on intrusive rock is characterized by having morphologically diverse halloysite, little chlorite, less illite, and poorly crystallized illite. Elemental addition/depletion shows evident differences between the two profiles. Differences in clay mineralogy and geochemical characteristics can be linked to parent lithology and magma cooling history, which influence texture, parent composition and condition of water-rock interaction. For example, beyond expectation, soil developed on extrusive rock is conducive to the formation of halloysite because prolonged water stagnation favors preferential transformation of feldspar into halloysite. In addition, for each profile, biotic weathering and abiotic weathering jointly determined the formation and transformation of clay minerals. The widespread presence of porous volcanic glass in the rhyolite-derived soil may provide favorable nutritional conditions for microbial growth, producing large amounts of organic acids, which are an important factor influencing the alteration of illite to secondary minerals.
{"title":"Clay mineralogical and geochemical responses to weathering of intrusive vs. extrusive rocks under a subtropical climate","authors":"Anbei Deng , Qian Fang , Qile Geng , Hanlie Hong , Lulu Zhao , Chen Liu , Xiaoliang Cai , Yiming Wang","doi":"10.1016/j.clay.2024.107644","DOIUrl":"10.1016/j.clay.2024.107644","url":null,"abstract":"<div><div>Clay mineralogy and geochemical characteristics of two soil profiles developed on intrusive (quartz monzonite) and extrusive (rhyolite) rocks in subtropical China were investigated to reveal clay mineralogical responses to weathering of different parent rocks under a subtropical climate. Overall chemical weathering intensity and biotic weathering intensity do not show significant differences between the two profiles, suggesting that the difference in parent lithology and rock's cooling history did not exert a significant control on weathering intensity. The differences between two profiles are mainly reflected in clay mineralogy and evolution of elemental loss/gain. The soil developed on intrusive rock is characterized by having morphologically diverse halloysite, little chlorite, less illite, and poorly crystallized illite. Elemental addition/depletion shows evident differences between the two profiles. Differences in clay mineralogy and geochemical characteristics can be linked to parent lithology and magma cooling history, which influence texture, parent composition and condition of water-rock interaction. For example, beyond expectation, soil developed on extrusive rock is conducive to the formation of halloysite because prolonged water stagnation favors preferential transformation of feldspar into halloysite. In addition, for each profile, biotic weathering and abiotic weathering jointly determined the formation and transformation of clay minerals. The widespread presence of porous volcanic glass in the rhyolite-derived soil may provide favorable nutritional conditions for microbial growth, producing large amounts of organic acids, which are an important factor influencing the alteration of illite to secondary minerals.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"264 ","pages":"Article 107644"},"PeriodicalIF":5.3,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142720800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-24DOI: 10.1016/j.clay.2024.107641
Nadine J. Kanik , Arkadiusz Derkowski , Stephan Kaufhold , Reiner Dohrmann
The recent and efficient spectroscopic, “O-D (using D2O water) method”, for layer charge (LC) determination of materials containing smectitic, wettable surfaces was used to identify subtle LC changes of thermally reacted samples (between ∼80 and 250 °C) from the Alternative Buffer Material (ABM) tests 2 and 5 conducted at the Äspö Hardrock Laboratory (HRL), Sweden. The tests were in situ intermediate-scale field experiments designed to simulate an engineered barrier around canisters containing radioactive waste within a deep geological repository. The tests consisted of several different bentonites compacted into 31 (ABM2) and 30 (ABM5) discs, stacked vertically around a central heater, and emplaced in a crystalline rock borehole in the HRL. Previous investigations of the ABM2 and 5 bentonites did not reveal specific mineralogical reactions of smectites, which may be observed at temperatures above 100 °C. The data presented in the present study, however, showed LC changes, in the ABM5 test, within the individual bentonite discs along a thermal gradient from the outside edge of the discs toward the heater contact, at which the temperature reached a maximum of 250 °C. Considerably less LC changes were observed for the bentonites in ABM2, in which heating reached a maximum of only ∼140 °C. Moreover, the LC data presented in the present study were found to be consistent with previously obtained cation exchange capacity (CEC) results and explained the observed changes in CEC along the thermal gradients across the discs. Both CEC and LC displayed a strong decreasing trend toward the heater contact in ABM5, and very weak increases toward the heater contact in ABM2. Of the several bentonites used in the tests, those with an initially higher LC, generally showed the greatest decrease of apparent LC after being reacted at high temperatures in the ABM5 package. The bentonites with an initially low to medium smectitic LC, appeared to undergo the least changes at the high temperatures achieved in the ABM5 package. The observed decrease of apparent LC is interpreted as resulting from the adsorption of interlayer cations at the siloxane surface, possibly in the ditrigonal cavity of the tetrahedral sheet, causing partial neutralization of the negative charge of the 2:1 layer. The minute increase in LC in the ABM2 package also showed a correlation with CEC but was within the measurement uncertainty.
{"title":"Probing subtle alterations of smectite layer charge by the spectroscopic OD method in bentonite from the Alternative Buffer Materials tests in Äspö, Sweden","authors":"Nadine J. Kanik , Arkadiusz Derkowski , Stephan Kaufhold , Reiner Dohrmann","doi":"10.1016/j.clay.2024.107641","DOIUrl":"10.1016/j.clay.2024.107641","url":null,"abstract":"<div><div>The recent and efficient spectroscopic, “O-D (using D<sub>2</sub>O water) method”, for layer charge (LC) determination of materials containing smectitic, wettable surfaces was used to identify subtle LC changes of thermally reacted samples (between ∼80 and 250 °C) from the Alternative Buffer Material (ABM) tests 2 and 5 conducted at the Äspö Hardrock Laboratory (HRL), Sweden. The tests were in situ intermediate-scale field experiments designed to simulate an engineered barrier around canisters containing radioactive waste within a deep geological repository. The tests consisted of several different bentonites compacted into 31 (ABM2) and 30 (ABM5) discs, stacked vertically around a central heater, and emplaced in a crystalline rock borehole in the HRL. Previous investigations of the ABM2 and 5 bentonites did not reveal specific mineralogical reactions of smectites, which may be observed at temperatures above 100 °C. The data presented in the present study, however, showed LC changes, in the ABM5 test, within the individual bentonite discs along a thermal gradient from the outside edge of the discs toward the heater contact, at which the temperature reached a maximum of 250 °C. Considerably less LC changes were observed for the bentonites in ABM2, in which heating reached a maximum of only ∼140 °C. Moreover, the LC data presented in the present study were found to be consistent with previously obtained cation exchange capacity (CEC) results and explained the observed changes in CEC along the thermal gradients across the discs. Both CEC and LC displayed a strong decreasing trend toward the heater contact in ABM5, and very weak increases toward the heater contact in ABM2. Of the several bentonites used in the tests, those with an initially higher LC, generally showed the greatest decrease of apparent LC after being reacted at high temperatures in the ABM5 package. The bentonites with an initially low to medium smectitic LC, appeared to undergo the least changes at the high temperatures achieved in the ABM5 package. The observed decrease of apparent LC is interpreted as resulting from the adsorption of interlayer cations at the siloxane surface, possibly in the ditrigonal cavity of the tetrahedral sheet, causing partial neutralization of the negative charge of the 2:1 layer. The minute increase in LC in the ABM2 package also showed a correlation with CEC but was within the measurement uncertainty.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"263 ","pages":"Article 107641"},"PeriodicalIF":5.3,"publicationDate":"2024-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1016/j.clay.2024.107624
Hao Zhang , Chaopeng Fu , Jianhao Ding , Guoqiang Xu , Chunhui Zhou , Zhenyu He , Zhimin Ou , Dongshen Tong , Minyang Qiu , Xiangdong Zhou , Xiaonian Li
An electrostatic adsorption-based, surface-enhanced Raman scattering (SERS) assay for the detection of charged analytes was developed, which utilized Ag-deposited laponite nanoparticles (Ag@Lap NPs) as both a SERS substrate and negatively charged absorber for the capture of positively charged analytes, such as methylene blue (MB) and rhodamine B (RB). The strong electrostatic interaction between the MB analyte and the Ag@Lap NPs resulted in an effective concentration of MB on the Ag content of Ag@Lap and provided a limit of detection (LOD) sensitivity of 10−11 M, which was more sensitive by a factor of 25,000 over the LOD of MB (0.25 × 10−6 M) in a similar SERS assay using bare Ag NPs with low charges. Additionally, a 100-fold improvement in LOD was also observed for RB analyte on Ag@Lap NPs over that on bare Ag NPs. Unlike positively charged, the negatively charged analytes, such as direct black-168 (DB-168) and methyl orange (MO), exhibited a weaker adsorption on the same negatively charged surface of Ag@Lap NPs due to electrostatic repulsion, leading to a lower SERS sensitivity. These results indicated that the electrostatic attraction between the analytes and SERS substrate played an important role in enriching the number of analytes on the active substrate to significantly improve the SERS intensity, suggesting a new strategy, which could be easily adapted to environmental analysis and biosensor applications by concentrating and detecting charged analytes, such as pollutants and dye molecules in nanotags.
{"title":"An ultra-sensitive SERS approach by electrostatic enrichment of charged analytes on Ag/laponite nanocomposites","authors":"Hao Zhang , Chaopeng Fu , Jianhao Ding , Guoqiang Xu , Chunhui Zhou , Zhenyu He , Zhimin Ou , Dongshen Tong , Minyang Qiu , Xiangdong Zhou , Xiaonian Li","doi":"10.1016/j.clay.2024.107624","DOIUrl":"10.1016/j.clay.2024.107624","url":null,"abstract":"<div><div>An electrostatic adsorption-based, surface-enhanced Raman scattering (SERS) assay for the detection of charged analytes was developed, which utilized Ag-deposited laponite nanoparticles (Ag@Lap NPs) as both a SERS substrate and negatively charged absorber for the capture of positively charged analytes, such as methylene blue (MB) and rhodamine B (RB). The strong electrostatic interaction between the MB analyte and the Ag@Lap NPs resulted in an effective concentration of MB on the Ag content of Ag@Lap and provided a limit of detection (LOD) sensitivity of 10<sup>−11</sup> M, which was more sensitive by a factor of 25,000 over the LOD of MB (0.25 × 10<sup>−6</sup> M) in a similar SERS assay using bare Ag NPs with low charges. Additionally, a 100-fold improvement in LOD was also observed for RB analyte on Ag@Lap NPs over that on bare Ag NPs. Unlike positively charged, the negatively charged analytes, such as direct black-168 (DB-168) and methyl orange (MO), exhibited a weaker adsorption on the same negatively charged surface of Ag@Lap NPs due to electrostatic repulsion, leading to a lower SERS sensitivity. These results indicated that the electrostatic attraction between the analytes and SERS substrate played an important role in enriching the number of analytes on the active substrate to significantly improve the SERS intensity, suggesting a new strategy, which could be easily adapted to environmental analysis and biosensor applications by concentrating and detecting charged analytes, such as pollutants and dye molecules in nanotags.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"263 ","pages":"Article 107624"},"PeriodicalIF":5.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702958","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1016/j.clay.2024.107638
Andrew J. Hambly, Jeroen S. van Duijneveldt, Paul J. Gates
The role that clay mineral acidity, specific surface area (SSA) and pore size distribution (PSD) have on the adsorption and oxidation of β-carotene by montmorillonite bleaching clays was investigated. Five commercially available clay minerals were studied, including three acid-activated montmorillonites (AACs) (K10, K30 and 22B), one aluminium-pillared montmorillonite (Al-PC) and an untreated montmorillonite (SWy-3). Each underwent physicochemical characterisation. X-ray diffraction and N2 gas sorption techniques provided structural and textural information. Titration with n-butylamine in the presence of Hammett and arylmethanol indicators characterised the concentration and strength of clay acid sites. The kinetics of β-carotene adsorption were then measured as a means of comparing their adsorptive power. The tendency of each clay to oxidise β-carotene to a variety of carotenoid-oxidation-products (COPs) was examined by analysing extracts of each clay with ultra-high-performance liquid-chromatography mass-spectrometry (UPLC-MS). The AACs adsorption and oxidation of β-carotene exceeded that of SWy-3 and Al-PC. This was attributed to a greater number of stronger acid sites, and a higher SSA. The clay PSD was also shown to play a significant role. 22B, which had a narrower PSD than K10 or K30, showed a lower tendency to adsorb β-carotene despite having the greatest number of strong acid sites. Lastly, the AACs had a greater oxidative power than SWy-3 or Al-PC and produced COPs in greater abundance than the other clays. They also produced more COPs of a higher oxidation state relative to β-carotene. These findings provide helpful information for the selection of efficient adsorbents for use in vegetable oil bleaching.
{"title":"Adsorption and oxidation of β-carotene by montmorillonite bleaching clays","authors":"Andrew J. Hambly, Jeroen S. van Duijneveldt, Paul J. Gates","doi":"10.1016/j.clay.2024.107638","DOIUrl":"10.1016/j.clay.2024.107638","url":null,"abstract":"<div><div>The role that clay mineral acidity, specific surface area (SSA) and pore size distribution (PSD) have on the adsorption and oxidation of β-carotene by montmorillonite bleaching clays was investigated. Five commercially available clay minerals were studied, including three acid-activated montmorillonites (AACs) (K10, K30 and 22B), one aluminium-pillared montmorillonite (Al-PC) and an untreated montmorillonite (SWy-3). Each underwent physicochemical characterisation. X-ray diffraction and N<sub>2</sub> gas sorption techniques provided structural and textural information. Titration with <em>n</em>-butylamine in the presence of Hammett and arylmethanol indicators characterised the concentration and strength of clay acid sites. The kinetics of β-carotene adsorption were then measured as a means of comparing their adsorptive power. The tendency of each clay to oxidise β-carotene to a variety of carotenoid-oxidation-products (COPs) was examined by analysing extracts of each clay with ultra-high-performance liquid-chromatography mass-spectrometry (UPLC-MS). The AACs adsorption and oxidation of β-carotene exceeded that of SWy-3 and Al-PC. This was attributed to a greater number of stronger acid sites, and a higher SSA. The clay PSD was also shown to play a significant role. 22B, which had a narrower PSD than K10 or K30, showed a lower tendency to adsorb β-carotene despite having the greatest number of strong acid sites. Lastly, the AACs had a greater oxidative power than SWy-3 or Al-PC and produced COPs in greater abundance than the other clays. They also produced more COPs of a higher oxidation state relative to β-carotene. These findings provide helpful information for the selection of efficient adsorbents for use in vegetable oil bleaching.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"263 ","pages":"Article 107638"},"PeriodicalIF":5.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1016/j.clay.2024.107639
Ibrahim Q. Mohammed , Tarang Sarin , Pragya Singh , Fadhil A. Lawa , Sherif Farouk , Khaled Al-Kahtany , Santanu Banerjee
Although glauconite is a common authigenic mineral in Late Cretaceous marine deposits, the influence of depositional conditions on the composition of glauconite is poorly understood. This study documents the origin and significance of five green clay layers in the Kurdistan region of Iraq in three formations, viz. Gulneri, Kometan, and Shiranish, comprised of carbonaceous mudstone, marl, marly limestone, dolomite, and limestone with occasional phosphates. Two sets of green clays within the ∼255 m thick, primarily transgressive marine sedimentary succession formed in distinct depositional domains, viz., inner shelf (proximal), and outer shelf to the middle slope (distal). Both sets of green clays formed primarily as pellets and as infillings. Characteristic reflections of ∼10 Å (001) and ∼ 3.35 Å (003), with high K2O (>7 wt%) content and lamellar structure exhibited by green clays indicated evolved to highly evolved glauconite. The proximal set of green clay was identified as evolved to highly evolved Al-glauconite with low Fe2O3(total) (<15 wt%) and high Al2O3 (>10 wt%). The distal set of green clay was highly evolved, containing high (>15 wt%) Fe2O3(total) and low (<10 wt%) Al2O3. The proximal set exhibited minor (<10 %) smectite interstratification, whereas the distal set of glauconite was almost entirely devoid of smectite interstratification. The compositional variation of glauconite across the basin was primarily dictated by substrate and depositional setting; the proximal set of glauconite formed by replacing Al-rich smectite and kaolinite, while the distal set formed in Fe-Al smectite. The phosphates within the glauconites formed under suboxic conditions during the initial stages of glauconitization.
{"title":"The influence of depositional conditions on chemical and mineralogical composition of glauconite: Case study from the Late Cretaceous Dokan Basin in Kurdistan region of Iraq","authors":"Ibrahim Q. Mohammed , Tarang Sarin , Pragya Singh , Fadhil A. Lawa , Sherif Farouk , Khaled Al-Kahtany , Santanu Banerjee","doi":"10.1016/j.clay.2024.107639","DOIUrl":"10.1016/j.clay.2024.107639","url":null,"abstract":"<div><div>Although glauconite is a common authigenic mineral in Late Cretaceous marine deposits, the influence of depositional conditions on the composition of glauconite is poorly understood. This study documents the origin and significance of five green clay layers in the Kurdistan region of Iraq in three formations, viz. Gulneri, Kometan, and Shiranish, comprised of carbonaceous mudstone, marl, marly limestone, dolomite, and limestone with occasional phosphates. Two sets of green clays within the ∼255 m thick, primarily transgressive marine sedimentary succession formed in distinct depositional domains, viz., inner shelf (proximal), and outer shelf to the middle slope (distal). Both sets of green clays formed primarily as pellets and as infillings. Characteristic reflections of ∼10 Å (001) and ∼ 3.35 Å (003), with high K<sub>2</sub>O (>7 wt%) content and lamellar structure exhibited by green clays indicated evolved to highly evolved glauconite. The proximal set of green clay was identified as evolved to highly evolved Al-glauconite with low Fe<sub>2</sub>O<sub>3</sub>(total) (<15 wt%) and high Al<sub>2</sub>O<sub>3</sub> (>10 wt%). The distal set of green clay was highly evolved, containing high (>15 wt%) Fe<sub>2</sub>O<sub>3</sub>(total) and low (<10 wt%) Al<sub>2</sub>O<sub>3</sub>. The proximal set exhibited minor (<10 %) smectite interstratification, whereas the distal set of glauconite was almost entirely devoid of smectite interstratification. The compositional variation of glauconite across the basin was primarily dictated by substrate and depositional setting; the proximal set of glauconite formed by replacing Al-rich smectite and kaolinite, while the distal set formed in Fe-Al smectite. The phosphates within the glauconites formed under suboxic conditions during the initial stages of glauconitization.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"263 ","pages":"Article 107639"},"PeriodicalIF":5.3,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-20DOI: 10.1016/j.clay.2024.107637
Fan Yang, Xue-Jing Ma, Jun-Hu Liu, Bi Chen, Kang Yang, Xin-Yu Liu, Wei-Bin Zhang
The rational design and optimization of electrode materials can effectively enhance the electrochemical performance of supercapacitors. In this work, by utilizing the microemulsion method to combine the nanoflake-structured Co-Ni-B material with the highly porous hollow tubular structure of acid-etched halloysite (eHal), the stable and porous Co-Ni-B@eHal composites have been successfully synthesized. Simultaneously, the bimetallic composition in Co-Ni-B can offer a wealth of redox reactions, while the eHal tubes provide support and facilitate the ionic transport channels. The optimal electrode exhibits a high specific capacitance of 1534 F g−1 at a current density of 0.5 A g−1 and maintains 99.67 % of its initial specific capacitance at a current density of 20 A g−1, demonstrating excellent rate performance. Furthermore, it shows remarkable cyclic stability, retaining a specific capacitance of approximately 100 % after 60,000 cycles at a current density of 5 A g−1. The assembled Co-Ni-B@eHal-based asymmetric supercapacitor operates at a working voltage of 1.5 V and achieves a maximum energy density of 105.73 W h kg−1 at a power density of 375 W kg−1. These findings offer new insights into the development of bimetallic boride-based nanostructures and clay minerals in the field of electrochemical energy storage.
合理设计和优化电极材料可有效提高超级电容器的电化学性能。本研究利用微乳液法将纳米片状结构的Co-Ni-B材料与酸蚀埃洛石（eHal）的高孔空心管状结构相结合，成功合成了稳定多孔的Co-Ni-B@eHal复合材料。同时，Co-Ni-B 中的双金属成分可提供丰富的氧化还原反应，而 eHal 管则可提供支持并促进离子传输通道。最佳电极在 0.5 A g-1 的电流密度下具有 1534 F g-1 的高比电容，在 20 A g-1 的电流密度下保持了 99.67 % 的初始比电容，表现出卓越的速率性能。此外，它还具有出色的循环稳定性，在 5 A g-1 的电流密度下循环 60,000 次后，比电容仍保持在约 100%。组装好的 Co-Ni-B@eHal 非对称超级电容器工作电压为 1.5 V，在功率密度为 375 W kg-1 的情况下，最大能量密度为 105.73 W h kg-1。这些发现为双金属硼基纳米结构和粘土矿物在电化学储能领域的发展提供了新的见解。
{"title":"Acid-etched halloysite and Co-Ni-B composites for high-performance supercapacitor application","authors":"Fan Yang, Xue-Jing Ma, Jun-Hu Liu, Bi Chen, Kang Yang, Xin-Yu Liu, Wei-Bin Zhang","doi":"10.1016/j.clay.2024.107637","DOIUrl":"10.1016/j.clay.2024.107637","url":null,"abstract":"<div><div>The rational design and optimization of electrode materials can effectively enhance the electrochemical performance of supercapacitors. In this work, by utilizing the microemulsion method to combine the nanoflake-structured Co-Ni-B material with the highly porous hollow tubular structure of acid-etched halloysite (eHal), the stable and porous Co-Ni-B@eHal composites have been successfully synthesized. Simultaneously, the bimetallic composition in Co-Ni-B can offer a wealth of redox reactions, while the eHal tubes provide support and facilitate the ionic transport channels. The optimal electrode exhibits a high specific capacitance of 1534 F g<sup>−1</sup> at a current density of 0.5 A g<sup>−1</sup> and maintains 99.67 % of its initial specific capacitance at a current density of 20 A g<sup>−1</sup>, demonstrating excellent rate performance. Furthermore, it shows remarkable cyclic stability, retaining a specific capacitance of approximately 100 % after 60,000 cycles at a current density of 5 A g<sup>−1</sup>. The assembled Co-Ni-B@eHal-based asymmetric supercapacitor operates at a working voltage of 1.5 V and achieves a maximum energy density of 105.73 W h kg<sup>−1</sup> at a power density of 375 W kg<sup>−1</sup>. These findings offer new insights into the development of bimetallic boride-based nanostructures and clay minerals in the field of electrochemical energy storage.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"263 ","pages":"Article 107637"},"PeriodicalIF":5.3,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702957","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-15DOI: 10.1016/j.clay.2024.107629
Chunhui Meng , Yunhong Jiao , Weihong Wu , Quan Li , Yuying Yang , Hongqiang Qu
Design of flame retardant epoxy resins (EP) with good flame retardant and mechanical properties has been an important topic of research. In this paper, an amino-functionalized phosphonitrile intermediate (HCCP-APTES) was synthesized by nucleophilic substitution reaction between hexachlorocyclotriphosphonitrile (HCCP) and 3-aminopropyltriethoxysilane (APTES). Hal-based flame retardants (HCCP-APTES@Hal) with different ratios were prepared by chemically cross-linking them on the outer surface of halloysite (Hal). Hal and HCCP-APTES@Hal were added to EP to study their effects on the flame retardant and mechanical properties of EP. The flame retardant (3HCCP-APTES@Hal) when the mass ratio of HCCP-APTES: Hal was 3:1 was added to EP at 6 wt% and the LOI value was 27.20 %. And the cone calorimetry test (CCT) results showed that the peak heat release rate (PHRR) and peak smoke production rate (PSPR) decreased by 36.84 % and 52.08 %, respectively, compared with pure EP. HCCP-APTES-modified Hal well-improved the interfacial compatibility with EP, which led to the enhancement of mechanical properties. This study proposes new ideas and strategies for the modification of Hal and the preparation of multifunctional Hal-based flame retardants in the future.
设计具有良好阻燃性和机械性能的阻燃环氧树脂（EP）一直是一项重要的研究课题。本文通过六氯环三磷腈（HCCP）和 3-氨基丙基三乙氧基硅烷（APTES）之间的亲核取代反应，合成了氨基官能化磷腈中间体（HCCP-APTES）。通过化学交联的方法，在哈洛来石（Hal）的外表面制备出了不同比例的哈洛来石基阻燃剂（HCCP-APTES@Hal）。将 Hal 和 HCCP-APTES@Hal 添加到 EP 中，研究它们对 EP 阻燃性能和机械性能的影响。当 HCCP-APTES.Hal 的质量比为 3:1 时，将阻燃剂（3HCCP-APTES@Hal）添加到 EP 中：Hal 的质量比为 3:1 时，在 EP 中的添加量为 6 wt%，LOI 值为 27.20 %。锥形量热试验（CCT）结果表明，与纯 EP 相比，峰值放热率（PHRR）和峰值产烟率（PSPR）分别降低了 36.84 % 和 52.08 %。HCCP-APTES 改性 Hal 很好地改善了与 EP 的界面相容性，从而提高了机械性能。这项研究为今后改性 Hal 和制备多功能 Hal 基阻燃剂提出了新的思路和策略。
{"title":"Synthesis of phosphonitrile derivative-modified halloysite flame retardants and their simultaneous enhancement of epoxy resins flame retardancy and mechanical properties","authors":"Chunhui Meng , Yunhong Jiao , Weihong Wu , Quan Li , Yuying Yang , Hongqiang Qu","doi":"10.1016/j.clay.2024.107629","DOIUrl":"10.1016/j.clay.2024.107629","url":null,"abstract":"<div><div>Design of flame retardant epoxy resins (EP) with good flame retardant and mechanical properties has been an important topic of research. In this paper, an amino-functionalized phosphonitrile intermediate (HCCP-APTES) was synthesized by nucleophilic substitution reaction between hexachlorocyclotriphosphonitrile (HCCP) and 3-aminopropyltriethoxysilane (APTES). Hal-based flame retardants (HCCP-APTES@Hal) with different ratios were prepared by chemically cross-linking them on the outer surface of halloysite (Hal). Hal and HCCP-APTES@Hal were added to EP to study their effects on the flame retardant and mechanical properties of EP. The flame retardant (3HCCP-APTES@Hal) when the mass ratio of HCCP-APTES: Hal was 3:1 was added to EP at 6 wt% and the LOI value was 27.20 %. And the cone calorimetry test (CCT) results showed that the peak heat release rate (PHRR) and peak smoke production rate (PSPR) decreased by 36.84 % and 52.08 %, respectively, compared with pure EP. HCCP-APTES-modified Hal well-improved the interfacial compatibility with EP, which led to the enhancement of mechanical properties. This study proposes new ideas and strategies for the modification of Hal and the preparation of multifunctional Hal-based flame retardants in the future.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"263 ","pages":"Article 107629"},"PeriodicalIF":5.3,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662747","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-14DOI: 10.1016/j.clay.2024.107628
Yijie Wang , Zhen-Yu Yin , Pierre-Yves Hicher , Liming Hu
The vapor sorption isotherm (VSI) is significant for studying soil-water interactions. The non-coincidence between the adsorption isotherm and desorption isotherm is termed hysteresis. The VSI of expansive soils exhibits a unique hysteresis at low humidity, whose underlying microscopic mechanism has not yet been fully investigated. In this study, molecular simulations were used to generate the VSI of Ca-montmorillonite (Ca-Mt), successfully reproducing the hydration-induced swelling and dehydration-induced shrinkage in Mt. The specially designed simulation procedure ensured that the simulated hysteresis was consistent with experimental results at the humidity range of 0.1–0.5. We analyzed the variations in external and interlayer water content, as well as the basal spacing with humidity, highlighting the influence of interlayer hydration in the presence of the hysteresis. Through analyses of density, cation hydration state, and hydrogen bond, we found that the cations moved away from the mineral surface during adsorption, providing more space for water retention, and the formation of hydrogen bonds impeded the desorption of newly added water, leading to the hysteresis. Furthermore, we compared the VSI results of Mts with different interlayer cations (Ca2+ and Na+). Within the humidity range of the VSI test, the hydration shell of interlayer Ca2+ comprised 8 water molecules, whereas the hydration shell of interlayer Na+ comprised 4–6 water molecules. In the desorption isotherm simulation, water molecules in the hydration shell of Na+ could be displaced by the mineral surface at low humidity, unlike those of Ca2+, resulting in distinct hysteresis shapes in their VSI results at low humidity.
水汽吸附等温线（VSI）对研究土壤与水的相互作用具有重要意义。吸附等温线和解吸等温线之间的不重合称为滞后。膨胀性土壤的 VSI 在低湿度时表现出一种独特的滞后现象，其微观机理尚未得到充分研究。本研究利用分子模拟生成了钙蒙脱石（Ca-Mt）的 VSI，成功地再现了 Mt 的水化诱导膨胀和脱水诱导收缩。我们分析了外部和层间含水量以及基底间距随湿度的变化，突出了层间水合作用对滞后现象的影响。通过对密度、阳离子水合状态和氢键的分析，我们发现阳离子在吸附过程中远离了矿物表面，为水分的保留提供了更大的空间，而氢键的形成阻碍了新加入水分的解吸，从而导致了滞后现象的产生。此外，我们还比较了含有不同层间阳离子（Ca2+ 和 Na+）的 Mts 的 VSI 结果。在 VSI 测试的湿度范围内，层间 Ca2+ 的水合壳由 8 个水分子组成，而层间 Na+ 的水合壳由 4-6 个水分子组成。在解吸等温线模拟中，与 Ca2+ 不同，Na+ 水合壳中的水分子在低湿度时可被矿物表面置换，从而导致它们在低湿度时的 VSI 结果出现明显的滞后形状。
{"title":"Hysteresis at low humidity on vapor sorption isotherm of Ca-montmorillonite: The key role of interlayer cations","authors":"Yijie Wang , Zhen-Yu Yin , Pierre-Yves Hicher , Liming Hu","doi":"10.1016/j.clay.2024.107628","DOIUrl":"10.1016/j.clay.2024.107628","url":null,"abstract":"<div><div>The vapor sorption isotherm (VSI) is significant for studying soil-water interactions. The non-coincidence between the adsorption isotherm and desorption isotherm is termed hysteresis. The VSI of expansive soils exhibits a unique hysteresis at low humidity, whose underlying microscopic mechanism has not yet been fully investigated. In this study, molecular simulations were used to generate the VSI of Ca-montmorillonite (Ca-Mt), successfully reproducing the hydration-induced swelling and dehydration-induced shrinkage in Mt. The specially designed simulation procedure ensured that the simulated hysteresis was consistent with experimental results at the humidity range of 0.1–0.5. We analyzed the variations in external and interlayer water content, as well as the basal spacing with humidity, highlighting the influence of interlayer hydration in the presence of the hysteresis. Through analyses of density, cation hydration state, and hydrogen bond, we found that the cations moved away from the mineral surface during adsorption, providing more space for water retention, and the formation of hydrogen bonds impeded the desorption of newly added water, leading to the hysteresis. Furthermore, we compared the VSI results of Mts with different interlayer cations (Ca<sup>2+</sup> and Na<sup>+</sup>). Within the humidity range of the VSI test, the hydration shell of interlayer Ca<sup>2+</sup> comprised 8 water molecules, whereas the hydration shell of interlayer Na<sup>+</sup> comprised 4–6 water molecules. In the desorption isotherm simulation, water molecules in the hydration shell of Na<sup>+</sup> could be displaced by the mineral surface at low humidity, unlike those of Ca<sup>2+</sup>, resulting in distinct hysteresis shapes in their VSI results at low humidity.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"263 ","pages":"Article 107628"},"PeriodicalIF":5.3,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142662748","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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