Pub Date : 2024-11-14DOI: 10.1016/j.micromeso.2024.113423
Eder Amayuelas , Sandeep Kumar Sharma , Jaideep Mor , Luis Bartolomé , Liam J.W. Johnson , Davide Caporale , Andrea Le Donne , Gianmarco Sigolo , Łukasz Scheller , Viviana Cristiglio , Pawel Zajdel , Simone Meloni , Yaroslav Grosu
Wetting-dewetting of nanoporous materials is of key importance for a wide range of natural and technological cases, which include separation, chromatography, ionic channels. Heterogeneous lyophobic systems (HLS) consisting of a lyophobic nanoporous material and a non-wetting liquid are attractive for thermomechanical energy storage, conversion and dissipation under pressure/temperature variations. In recent years, metal-organic frameworks (MOFs) are entering many fields, including those mentioned above due to their wide structural diversity, structural flexibility and high tunability. In this work, we investigate the hitherto unexplored effects of forced wetting (intrusion-extrusion) of a hybrid mixed-linker ZIF-7-8 MOF (Zn-methylimidazole0.794–benzimidazole0.206) with water. Surprisingly, despite its structural similarity to ZIF-8, the hybrid ZIF-7-8 MOF demonstrates a non-hysteretic water intrusion-extrusion cycle that is in strong contrast to both ZIF-8 and ZIF-7 MOFs, which have pronounced intrusion-extrusion hysteresis. We used a combination of high-pressure intrusion-extrusion experiments, neutron diffraction structural analysis and atomistic simulations to put forward several hypotheses regarding the observed transformation from shock absorber/bumper behavior of ZIF-8 and ZIF-7 to molecular spring behavior of hybrid ZIF-7-8. These results open a new route for tuning the intrusion-extrusion (wetting-dewetting) hysteresis for numerous applications.
{"title":"Effect of linker hybridization on the wetting of hydrophobic metal-organic frameworks","authors":"Eder Amayuelas , Sandeep Kumar Sharma , Jaideep Mor , Luis Bartolomé , Liam J.W. Johnson , Davide Caporale , Andrea Le Donne , Gianmarco Sigolo , Łukasz Scheller , Viviana Cristiglio , Pawel Zajdel , Simone Meloni , Yaroslav Grosu","doi":"10.1016/j.micromeso.2024.113423","DOIUrl":"10.1016/j.micromeso.2024.113423","url":null,"abstract":"<div><div>Wetting-dewetting of nanoporous materials is of key importance for a wide range of natural and technological cases, which include separation, chromatography, ionic channels. Heterogeneous lyophobic systems (HLS) consisting of a lyophobic nanoporous material and a non-wetting liquid are attractive for thermomechanical energy storage, conversion and dissipation under pressure/temperature variations. In recent years, metal-organic frameworks (MOFs) are entering many fields, including those mentioned above due to their wide structural diversity, structural flexibility and high tunability. In this work, we investigate the hitherto unexplored effects of forced wetting (intrusion-extrusion) of a hybrid mixed-linker ZIF-7-8 MOF (Zn-methylimidazole<sub>0.794</sub>–benzimidazole<sub>0.206</sub>) with water. Surprisingly, despite its structural similarity to ZIF-8, the hybrid ZIF-7-8 MOF demonstrates a non-hysteretic water intrusion-extrusion cycle that is in strong contrast to both ZIF-8 and ZIF-7 MOFs, which have pronounced intrusion-extrusion hysteresis. We used a combination of high-pressure intrusion-extrusion experiments, neutron diffraction structural analysis and atomistic simulations to put forward several hypotheses regarding the observed transformation from shock absorber/bumper behavior of ZIF-8 and ZIF-7 to molecular spring behavior of hybrid ZIF-7-8. These results open a new route for tuning the intrusion-extrusion (wetting-dewetting) hysteresis for numerous applications.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"383 ","pages":"Article 113423"},"PeriodicalIF":4.8,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658628","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.micromeso.2024.113413
Elsa Tsegay Tikue , Su Kyung Kang , Hee Ju Ko , Se Wan Kim , Abduljelil Worku Sabir , Pyung Soo Lee
Zeolite-based polymer composites have garnered significant attention for their applications in separation, catalysis, and energy storage, owing to the unique properties of zeolites. The development of core–shell structures provides a promising strategy to enhance these properties, enabling the fine-tuning of zeolite characteristics within composite films. In this study, we present an innovative approach that leverages surface zeta potential differences to facilitate the growth of an organophilic metal–organic framework (MOF) on hydrophilic zeolite surfaces. Specifically, UiO-66 was successfully attached and grown on Linde Type A (LTA) zeolite particles, resulting in the formation of a robust core–shell structure (LTA@UiO-66). This core–shell architecture significantly minimized interfacial voids when embedded into a polyimide (PI, Matrimid® 5218) matrix, yielding composite films (LTA@UiO-66/PI) with superior mechanical integrity and enhanced gas-separation performance. The LTA@UiO-66/PI films demonstrated remarkable ideal selectivity for O2/N2 (10.7) and CO2/CH4 (47), outperforming traditional LTA/PI composites. These enhancements are attributed to the synergistic effects between the LTA core and the UiO-66 shell, which preserve the molecular sieving capability of the zeolite while ensuring strong adhesion and a void-free interface with the polymer matrix. The findings underscore the significant potential of zeolite-based core–shell structures in advancing industrial applications, particularly in the domains of sustainable gas separation and purification technologies.
{"title":"Fabrication of LTA zeolite core and UiO-66 shell structures via surface zeta potential modulation and sequential seeded growth for zeolite/polymer composite membranes","authors":"Elsa Tsegay Tikue , Su Kyung Kang , Hee Ju Ko , Se Wan Kim , Abduljelil Worku Sabir , Pyung Soo Lee","doi":"10.1016/j.micromeso.2024.113413","DOIUrl":"10.1016/j.micromeso.2024.113413","url":null,"abstract":"<div><div>Zeolite-based polymer composites have garnered significant attention for their applications in separation, catalysis, and energy storage, owing to the unique properties of zeolites. The development of core–shell structures provides a promising strategy to enhance these properties, enabling the fine-tuning of zeolite characteristics within composite films. In this study, we present an innovative approach that leverages surface zeta potential differences to facilitate the growth of an organophilic metal–organic framework (MOF) on hydrophilic zeolite surfaces. Specifically, UiO-66 was successfully attached and grown on Linde Type A (LTA) zeolite particles, resulting in the formation of a robust core–shell structure (LTA@UiO-66). This core–shell architecture significantly minimized interfacial voids when embedded into a polyimide (PI, Matrimid® 5218) matrix, yielding composite films (LTA@UiO-66/PI) with superior mechanical integrity and enhanced gas-separation performance. The LTA@UiO-66/PI films demonstrated remarkable ideal selectivity for O<sub>2</sub>/N<sub>2</sub> (10.7) and CO<sub>2</sub>/CH<sub>4</sub> (47), outperforming traditional LTA/PI composites. These enhancements are attributed to the synergistic effects between the LTA core and the UiO-66 shell, which preserve the molecular sieving capability of the zeolite while ensuring strong adhesion and a void-free interface with the polymer matrix. The findings underscore the significant potential of zeolite-based core–shell structures in advancing industrial applications, particularly in the domains of sustainable gas separation and purification technologies.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"383 ","pages":"Article 113413"},"PeriodicalIF":4.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.micromeso.2024.113412
Ziheng Shen , Alexander I. Wiechert , Seungrag Choi , Austin P. Ladshaw , Lawrence L. Tavlarides , Costas Tsouris , Sotira Yiacoumi
Reprocessing is considered a competent strategy for spent nuclear fuel management, yet radioiodine (129I) is emitted in reprocessing off-gas as a hazardous byproduct. Silver functionalized silica aerogel (Ag0-aerogel), a promising iodine capture material, experiences a reduction in its capacity after prolonged exposure to off-gas components at elevated temperatures, a phenomenon termed as aging. To fully understand this process, we isolated the contribution of each aging factor, exposing Ag0-aerogel samples to N2 and dry air gas streams, respectively, at 150 °C for different time periods. Aged samples were loaded with I2 to examine the capacity change and comprehensively characterized to investigate the evolution of their properties. Results show that temperature alone did not alter Ag0-aerogel's capacity but triggered Ag0 nanoparticles sintering and generated organic sulfur species. The presence of O2 reduced the capacity by ∼20 %, causing (i) formation of silver sulfide (Ag2S) crystals and (ii) oxidation of Ag-thiolate (Ag-S-r) to Ag sulfonate (Ag-SO3-r). Given that Ag2S readily adsorbs I2, the formation of Ag-SO3-r is the major inhibitor for iodine adsorption. This hypothesis was supported by density functional theory (DFT) simulations. These findings unraveled key mechanisms of Ag0-aerogel aging, which are useful in the development of materials that withstand realistic spent-nuclear-fuel-reprocessing off-gas conditions.
{"title":"Influence of elevated temperature and oxygen on the capture of radioactive iodine by silver functionalized silica aerogel","authors":"Ziheng Shen , Alexander I. Wiechert , Seungrag Choi , Austin P. Ladshaw , Lawrence L. Tavlarides , Costas Tsouris , Sotira Yiacoumi","doi":"10.1016/j.micromeso.2024.113412","DOIUrl":"10.1016/j.micromeso.2024.113412","url":null,"abstract":"<div><div>Reprocessing is considered a competent strategy for spent nuclear fuel management, yet radioiodine (<sup>129</sup>I) is emitted in reprocessing off-gas as a hazardous byproduct. Silver functionalized silica aerogel (Ag<sup>0</sup>-aerogel), a promising iodine capture material, experiences a reduction in its capacity after prolonged exposure to off-gas components at elevated temperatures, a phenomenon termed as aging. To fully understand this process, we isolated the contribution of each aging factor, exposing Ag<sup>0</sup>-aerogel samples to N<sub>2</sub> and dry air gas streams, respectively, at 150 °C for different time periods. Aged samples were loaded with I<sub>2</sub> to examine the capacity change and comprehensively characterized to investigate the evolution of their properties. Results show that temperature alone did not alter Ag<sup>0</sup>-aerogel's capacity but triggered Ag<sup>0</sup> nanoparticles sintering and generated organic sulfur species. The presence of O<sub>2</sub> reduced the capacity by ∼20 %, causing (i) formation of silver sulfide (Ag<sub>2</sub>S) crystals and (ii) oxidation of Ag-thiolate (Ag-S-r) to Ag sulfonate (Ag-SO<sub>3</sub>-r). Given that Ag<sub>2</sub>S readily adsorbs I<sub>2</sub>, the formation of Ag-SO<sub>3</sub>-r is the major inhibitor for iodine adsorption. This hypothesis was supported by density functional theory (DFT) simulations. These findings unraveled key mechanisms of Ag<sup>0</sup>-aerogel aging, which are useful in the development of materials that withstand realistic spent-nuclear-fuel-reprocessing off-gas conditions.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"383 ","pages":"Article 113412"},"PeriodicalIF":4.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658630","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.micromeso.2024.113408
Sebastian Pfeifer , Christoph Pasel , Christian Bläker , Tobias Eckardt , Nele Klinkenberg , Jakob Eggebrecht , Kristin Gleichmann , Dieter Bathen
In this study, the catalytic reaction of H2S and CO2 to COS and H2O during the adsorptive treatment of a model natural gas on modified Linde type-A (LTA) zeolites is investigated. Breakthrough curves of all 4 components were measured at 25 °C in a fixed bed adsorber on eight NaA and CaNaA zeolites with different calcium exchange ratios. The COS breakthrough curves are discussed with regard to the properties of the materials in the exchange series (number of cations, cation position, cation type). The COS curves reveal that catalytic formation of COS occurs at cation positions II and III, whereas no COS formation occurs at position I. Ca2+-ions are more catalytically active than Na+-Ions due to their higher ionic charge. The quantities of COS formed prove that the reaction water plays a significant role in the termination of the reaction. The reaction water adsorbs on the catalytically active cations so that no further COS formation can occur. The feed water, on the other hand, mainly leads to a displacement of the previously adsorbed components (CO2, H2S, COS).
本研究调查了改性林德 A 型（LTA）沸石在吸附处理模型天然气过程中将 H2S 和 CO2 催化反应为 COS 和 H2O 的情况。在 25 °C 的固定床吸附器中，在不同钙交换比的八种 NaA 和 CaNaA 沸石上测量了所有四种成分的突破曲线。根据交换系列材料的特性（阳离子数量、阳离子位置、阳离子类型）对 COS 突破曲线进行了讨论。COS 曲线显示，阳离子位置 II 和 III 会催化形成 COS，而位置 I 则不会形成 COS。形成的 COS 数量证明，反应水在反应终止过程中起着重要作用。反应水吸附在具有催化活性的阳离子上，因此不会再形成 COS。另一方面，进料水主要导致先前吸附的成分（CO2、H2S、COS）被置换。
{"title":"Catalytic COS formation on ion-exchanged LTA zeolites during adsorption","authors":"Sebastian Pfeifer , Christoph Pasel , Christian Bläker , Tobias Eckardt , Nele Klinkenberg , Jakob Eggebrecht , Kristin Gleichmann , Dieter Bathen","doi":"10.1016/j.micromeso.2024.113408","DOIUrl":"10.1016/j.micromeso.2024.113408","url":null,"abstract":"<div><div>In this study, the catalytic reaction of H<sub>2</sub>S and CO<sub>2</sub> to COS and H<sub>2</sub>O during the adsorptive treatment of a model natural gas on modified Linde type-A (LTA) zeolites is investigated. Breakthrough curves of all 4 components were measured at 25 °C in a fixed bed adsorber on eight NaA and CaNaA zeolites with different calcium exchange ratios. The COS breakthrough curves are discussed with regard to the properties of the materials in the exchange series (number of cations, cation position, cation type). The COS curves reveal that catalytic formation of COS occurs at cation positions II and III, whereas no COS formation occurs at position I. Ca<sup>2+</sup>-ions are more catalytically active than Na<sup>+</sup>-Ions due to their higher ionic charge. The quantities of COS formed prove that the reaction water plays a significant role in the termination of the reaction. The reaction water adsorbs on the catalytically active cations so that no further COS formation can occur. The feed water, on the other hand, mainly leads to a displacement of the previously adsorbed components (CO<sub>2</sub>, H<sub>2</sub>S, COS).</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"383 ","pages":"Article 113408"},"PeriodicalIF":4.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.micromeso.2024.113410
Mei Yang , Yu Li , Xiaohui Shi , Ning Fen , Lu Ma , Wenxin Ji , Yi Xiao , Keren Shi , Yonggang Sun , Yuanyuan Li , Yulong Ma
The generation of a large amount of coal gasification coarse slag (CGCS) restricts the sustainable development of the modern coal chemical industry. This paper uses CGCS as raw material, adopts a solid phase synthesis method, saves water resources, is a new method of synthesizing zeolite with low secondary pollution. Different types of anions were used to induce the synthesis of zeolites. Using XRD, FT-IR, 27Al-NMR, 29Si-NMR, BET, SEM, and experimental research methods, the activation and depolymerization of CGCS in the solid phase reaction and the guiding role of anions in crystal growth were studied. The results revealed that the anionic structure with triple rotational axis symmetry can induce the synthesis of single-phase CAN zeolite. Using this rule, CAN zeolite was synthesized using CGCS as raw material and Cr6+ containing wastewater with triple rotation axis symmetry as the structural guide agent, and Cr6+ in wastewater was structurally fixed. Compared to the adsorption effect of CGCS on Cr6+, the results showed that the synthesized CAN zeolite was found to effectively fix Cr6+ (74.98 mg/g) from wastewater, which was much higher than that of CGCS (24.85 mg/g).
大量煤气化粗渣（CGCS）的产生制约了现代煤化工的可持续发展。本文以煤气化粗渣为原料，采用固相合成法，节约水资源，是一种低二次污染的沸石合成新方法。采用不同类型的阴离子诱导合成沸石。利用 XRD、FT-IR、27Al-NMR、29Si-NMR、BET、SEM 和实验研究方法，研究了 CGCS 在固相反应中的活化和解聚以及阴离子对晶体生长的引导作用。结果表明，具有三重旋转轴对称性的阴离子结构可诱导合成单相 CAN 沸石。利用这一规律，以 CGCS 为原料，以具有三重旋转轴对称性的含 Cr6+ 废水为结构引导剂，合成了 CAN 沸石，并对废水中的 Cr6+ 进行了结构固定。结果表明，与 CGCS 对 Cr6+ 的吸附效果相比，合成的 CAN 沸石能有效固定废水中的 Cr6+（74.98 mg/g），远高于 CGCS（24.85 mg/g）。
{"title":"Study of the structure guide mechanism of solid phase synthesis of CAN zeolite from coal gasification slag and its fixation of the Cr6+ structure in wastewater","authors":"Mei Yang , Yu Li , Xiaohui Shi , Ning Fen , Lu Ma , Wenxin Ji , Yi Xiao , Keren Shi , Yonggang Sun , Yuanyuan Li , Yulong Ma","doi":"10.1016/j.micromeso.2024.113410","DOIUrl":"10.1016/j.micromeso.2024.113410","url":null,"abstract":"<div><div>The generation of a large amount of coal gasification coarse slag (CGCS) restricts the sustainable development of the modern coal chemical industry. This paper uses CGCS as raw material, adopts a solid phase synthesis method, saves water resources, is a new method of synthesizing zeolite with low secondary pollution. Different types of anions were used to induce the synthesis of zeolites. Using XRD, FT-IR, <sup>27</sup>Al-NMR, <sup>29</sup>Si-NMR, BET, SEM, and experimental research methods, the activation and depolymerization of CGCS in the solid phase reaction and the guiding role of anions in crystal growth were studied. The results revealed that the anionic structure with triple rotational axis symmetry can induce the synthesis of single-phase CAN zeolite. Using this rule, CAN zeolite was synthesized using CGCS as raw material and Cr<sup>6+</sup> containing wastewater with triple rotation axis symmetry as the structural guide agent, and Cr<sup>6+</sup> in wastewater was structurally fixed. Compared to the adsorption effect of CGCS on Cr<sup>6+</sup>, the results showed that the synthesized CAN zeolite was found to effectively fix Cr<sup>6+</sup> (74.98 mg/g) from wastewater, which was much higher than that of CGCS (24.85 mg/g).</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"383 ","pages":"Article 113410"},"PeriodicalIF":4.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658612","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-12DOI: 10.1016/j.micromeso.2024.113411
Abd-Alkhaliq Salih Mijwel , Nur Irfah Mohd Pauzi , Haiyam Mohammed Alayan , Haitham Abdulmohsin Afan , Ali Najah Ahmed , Mustafa M. Aljumaily , Mohammed A. Al-Saadi , Ahmed El-Shafie
Water quality nowadays, under climate change, has become a risk and challenging problem to save water from deterioration. Advanced solutions such as nanomaterials and artificial intelligence for simulation have become some of the best and essential solutions. Therefore, this study assessed the artificial intelligence models' accuracy in simulating the elimination of Bisphenol A (BPA) using synthesized carbon nanotubes (CNTs). We concluded that the pseudo-second-order model's (R2) correlation coefficient is (0.999) significantly higher than the other models. Because the findings between the Model and Actual Values are so accurate, the adsorption of BPA on CNT could be modeled using the pseudo-second-order model, qe = 144.928(mg/g) and K2 = 0.0016. The correlation coefficient of Pseudo-First-Order model's (R2) is (0.825) qe = 27.107(mg/g) and K1 = 0.0161, and the Intraparticle diffusion model's (R2) is (0.821),qe = 151.98(mg/g) and Kd = 2.4. The Langmuir model performed the best in isothermal experiments, with correlation coefficients of R2 = 0.9441, qm = 181.81, and RL = 0.0375. Based on the information provided, we may conclude that the Langmuir model accounts for more BPA adsorption than the other models. We employed the feedforward neural network (FFNN) and the recurrent neural network (RNN). The FFNN achieved a coefficient of 0.971, while the RNN obtained a higher correlation coefficient of 0.98.
{"title":"Artificial intelligence -driven insights into bisphenol A removal using synthesized carbon nanotubes","authors":"Abd-Alkhaliq Salih Mijwel , Nur Irfah Mohd Pauzi , Haiyam Mohammed Alayan , Haitham Abdulmohsin Afan , Ali Najah Ahmed , Mustafa M. Aljumaily , Mohammed A. Al-Saadi , Ahmed El-Shafie","doi":"10.1016/j.micromeso.2024.113411","DOIUrl":"10.1016/j.micromeso.2024.113411","url":null,"abstract":"<div><div>Water quality nowadays, under climate change, has become a risk and challenging problem to save water from deterioration. Advanced solutions such as nanomaterials and artificial intelligence for simulation have become some of the best and essential solutions. Therefore, this study assessed the artificial intelligence models' accuracy in simulating the elimination of Bisphenol A (BPA) using synthesized carbon nanotubes (CNTs). We concluded that the pseudo-second-order model's (R2) correlation coefficient is (0.999) significantly higher than the other models. Because the findings between the Model and Actual Values are so accurate, the adsorption of BPA on CNT could be modeled using the pseudo-second-order model, qe = 144.928(mg/g) and K2 = 0.0016. The correlation coefficient of Pseudo-First-Order model's (R2) is (0.825) qe = 27.107(mg/g) and K1 = 0.0161, and the Intraparticle diffusion model's (R2) is (0.821),qe = 151.98(mg/g) and Kd = 2.4. The Langmuir model performed the best in isothermal experiments, with correlation coefficients of R2 = 0.9441, qm = 181.81, and RL = 0.0375. Based on the information provided, we may conclude that the Langmuir model accounts for more BPA adsorption than the other models. We employed the feedforward neural network (FFNN) and the recurrent neural network (RNN). The FFNN achieved a coefficient of 0.971, while the RNN obtained a higher correlation coefficient of 0.98.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"383 ","pages":"Article 113411"},"PeriodicalIF":4.8,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-10DOI: 10.1016/j.micromeso.2024.113388
K.S.C. Morton , M. Appel , C.L.M. Woodward , J. Armstrong , A.J. O’Malley
The dynamical behaviour of common lignin derivatives anisole and guaiacol within commercial acidic zeolite catalysts was investigated using quasielastic neutron scattering (QENS) and molecular dynamics (MD) simulations, to understand the diffusion mechanisms of simpler lignin-derived compounds in potential industrial catalysts for their conversion into value-added fuels and chemicals. QENS experiments probing timescales of 340 ps observed and quantified localised jump diffusion within the frameworks of industrial acidic H-Y and H-Beta samples (Si/Al = 15 and 12.5 respectively), and methyl rotations which differed in rate between systems. As the zeolite pore diameter increased from H-Beta to H-Y, and as molecular size decreased from guaiacol to anisole, an increase in the proportion of diffusing molecules was observed by a factor of 2–3 across the temperature range. Faster rates of diffusion, longer jump distances, and expanded regions of confined diffusion were observed for the smaller anisole molecule in both frameworks and for both molecules in H-Y over H-Beta, indicating that the ratio between catalyst pore diameter and molecular size significantly affects local diffusivity in these catalysts. QENS observables generated from the MD simulations over the experimental timescale reproduced this confined diffusion, along with the trends in mobility with molecular size and framework topology. Upon probing an extended nanosecond timescale with the MD, anisole still diffused more quickly than guaiacol in both zeolites, and guaiacol diffused more quickly in H-Y than in H-Beta as per the localised motions. However, in contrast with experimentally observed/modelled localised motions, nanoscale diffusion of anisole was faster in H-Beta than in H-Y due to the straight channels of H-Beta facilitating continuous diffusion over the nanoscale, whereas in H-Y the diffusion rate beyond the confining region was slower due to the barriers to jumping between supercages. In addition to its larger molecular size, guaiacol’s hydroxyl group allowed for stronger interactions with the zeolite Brønsted acid sites than the methoxy group which both molecules possess, hindering diffusion further. The study highlights the complex interplay between molecular shape, functionality, steric pore hindrance and acid site interactions on the local and nanoscale mobility of important derivatives of lignin in potential catalysts for their conversion to fuels and useful chemicals.
{"title":"The effect of pore structure on the local and nanoscale mobility of anisole and guaiacol in commercial zeolite catalysts","authors":"K.S.C. Morton , M. Appel , C.L.M. Woodward , J. Armstrong , A.J. O’Malley","doi":"10.1016/j.micromeso.2024.113388","DOIUrl":"10.1016/j.micromeso.2024.113388","url":null,"abstract":"<div><div>The dynamical behaviour of common lignin derivatives anisole and guaiacol within commercial acidic zeolite catalysts was investigated using quasielastic neutron scattering (QENS) and molecular dynamics (MD) simulations, to understand the diffusion mechanisms of simpler lignin-derived compounds in potential industrial catalysts for their conversion into value-added fuels and chemicals. QENS experiments probing timescales of <span><math><mo>∼</mo></math></span>340 ps observed and quantified localised jump diffusion within the frameworks of industrial acidic H-Y and H-Beta samples (Si/Al = 15 and 12.5 respectively), and methyl rotations which differed in rate between systems. As the zeolite pore diameter increased from H-Beta to H-Y, and as molecular size decreased from guaiacol to anisole, an increase in the proportion of diffusing molecules was observed by a factor of 2–3 across the temperature range. Faster rates of diffusion, longer jump distances, and expanded regions of confined diffusion were observed for the smaller anisole molecule in both frameworks and for both molecules in H-Y over H-Beta, indicating that the ratio between catalyst pore diameter and molecular size significantly affects local diffusivity in these catalysts. QENS observables generated from the MD simulations over the experimental timescale reproduced this confined diffusion, along with the trends in mobility with molecular size and framework topology. Upon probing an extended nanosecond timescale with the MD, anisole still diffused more quickly than guaiacol in both zeolites, and guaiacol diffused more quickly in H-Y than in H-Beta as per the localised motions. However, in contrast with experimentally observed/modelled localised motions, nanoscale diffusion of anisole was faster in H-Beta than in H-Y due to the straight channels of H-Beta facilitating continuous diffusion over the nanoscale, whereas in H-Y the diffusion rate beyond the confining region was slower due to the barriers to jumping between supercages. In addition to its larger molecular size, guaiacol’s hydroxyl group allowed for stronger interactions with the zeolite Brønsted acid sites than the methoxy group which both molecules possess, hindering diffusion further. The study highlights the complex interplay between molecular shape, functionality, steric pore hindrance and acid site interactions on the local and nanoscale mobility of important derivatives of lignin in potential catalysts for their conversion to fuels and useful chemicals.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"383 ","pages":"Article 113388"},"PeriodicalIF":4.8,"publicationDate":"2024-11-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.micromeso.2024.113398
Ann M. Kulisiewicz , Sergio J. Garibay , Trenton B. Tovar , Matthew A. Browe , Jill B. Harland , Jason K. Navin
Metal-organic frameworks (MOFs) with Zr-based secondary building units (SBUs) have shown promise as materials for the catalytic degradation of chemical warfare agents (CWAs). The Zr-based SBU within the MOF has been previously determined to be the active site for catalytic hydrolysis reactions within these materials. However, MOF structure dictates access to the SBU active sites with microporous MOFs showing catalysis solely on the surface of the particles of the MOF and MOFs with analogous SBUs exhibiting different reaction rates under the same reaction conditions. The multitude of variables inherent to MOF structures (e.g. pore size, pore structure, connectivity, crystal size, functional groups, defects, and monocarboxylic acid modulators (MCAMs) used in synthesis) complicate the fundamental understanding of the SBU's reactivity in the hydrolysis reaction independent of topological constraints. In this work, we have explored the catalytic activity of a simplified SBU system consisting of Zr6 and Zr12 clusters decorated with MCAMs varying in size and functionality to simulate the chemical environment of the SBU within the MOF structure. The zirconium clusters were then supported on mesoporous silica (SBA-15) functionalized with either sulfuric or phosphoric acid groups that bind to the zirconium nodes, covalently tethering the clusters to the silica support. These novel porous materials were designed to mimic the porous nature of the MOF structure to determine the effect on hydrolysis reactivity. The final silica-bound zirconium clusters showed enhanced reactivity towards the hydrolysis of dimethyl nitrophosphate (DMNP), a nerve agent simulant, under buffered conditions compared to the bare Zr clusters and showed key differences in the catalytic activity based on the chemical environment imparted by both the MCAM and the modified support. In addition, the use of an acid-modified silica scaffolding allowed for the incorporation of adjacent amine moieties on the SBA-15 support to facilitate hydrolysis of DMNP under neutral aqueous conditions, a benefit over typical Zr-based MOF catalysts that require a buffer for appreciable reactivity.
{"title":"Controlling the heterogeneous catalysis of zirconium clusters within a porous SBA-15 scaffold","authors":"Ann M. Kulisiewicz , Sergio J. Garibay , Trenton B. Tovar , Matthew A. Browe , Jill B. Harland , Jason K. Navin","doi":"10.1016/j.micromeso.2024.113398","DOIUrl":"10.1016/j.micromeso.2024.113398","url":null,"abstract":"<div><div>Metal-organic frameworks (MOFs) with Zr-based secondary building units (SBUs) have shown promise as materials for the catalytic degradation of chemical warfare agents (CWAs). The Zr-based SBU within the MOF has been previously determined to be the active site for catalytic hydrolysis reactions within these materials. However, MOF structure dictates access to the SBU active sites with microporous MOFs showing catalysis solely on the surface of the particles of the MOF and MOFs with analogous SBUs exhibiting different reaction rates under the same reaction conditions. The multitude of variables inherent to MOF structures (e.g. pore size, pore structure, connectivity, crystal size, functional groups, defects, and monocarboxylic acid modulators (MCAMs) used in synthesis) complicate the fundamental understanding of the SBU's reactivity in the hydrolysis reaction independent of topological constraints. In this work, we have explored the catalytic activity of a simplified SBU system consisting of Zr<sub>6</sub> and Zr<sub>12</sub> clusters decorated with MCAMs varying in size and functionality to simulate the chemical environment of the SBU within the MOF structure. The zirconium clusters were then supported on mesoporous silica (SBA-15) functionalized with either sulfuric or phosphoric acid groups that bind to the zirconium nodes, covalently tethering the clusters to the silica support. These novel porous materials were designed to mimic the porous nature of the MOF structure to determine the effect on hydrolysis reactivity. The final silica-bound zirconium clusters showed enhanced reactivity towards the hydrolysis of dimethyl nitrophosphate (DMNP), a nerve agent simulant, under buffered conditions compared to the bare Zr clusters and showed key differences in the catalytic activity based on the chemical environment imparted by both the MCAM and the modified support. In addition, the use of an acid-modified silica scaffolding allowed for the incorporation of adjacent amine moieties on the SBA-15 support to facilitate hydrolysis of DMNP under neutral aqueous conditions, a benefit over typical Zr-based <span>MOF</span> catalysts that require a buffer for appreciable reactivity.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"382 ","pages":"Article 113398"},"PeriodicalIF":4.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656289","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-09DOI: 10.1016/j.micromeso.2024.113405
E.V. Butyrskaya , T.V. Eliseeva , D.T. Le
The adsorption isotherms of L-histidine on MKN-SWCNT-S1 CNTs from aqueous solution at temperatures of 25, 35, 45, 55, 65 and 80 °C were interpreted within the framework of the single-layer cluster adsorption model. A new approach to determine the equilibrium parameters of the cluster adsorption isotherm equation and sorbate structure on CNTs, as well as a nonlinear modelling method, was applied. To confirm the cluster nature of amino acid adsorption on CNTs, the clustering criterion proposed in the previous work was applied, and the cluster structure was evaluated, which is significant for the application of CNTs in biomedicine. The found equilibrium parameters of adsorption were applied to the determination of thermodynamic characteristics of adsorption (changes in Gibbs energy, enthalpy and entropy) of L-histidine on CNTs and the character of adsorption was analysed.
{"title":"Cluster adsorption of L-histidine on carbon nanotubes at different temperatures","authors":"E.V. Butyrskaya , T.V. Eliseeva , D.T. Le","doi":"10.1016/j.micromeso.2024.113405","DOIUrl":"10.1016/j.micromeso.2024.113405","url":null,"abstract":"<div><div>The adsorption isotherms of L-histidine on MKN-SWCNT-S1 CNTs from aqueous solution at temperatures of 25, 35, 45, 55, 65 and 80 °C were interpreted within the framework of the single-layer cluster adsorption model. A new approach to determine the equilibrium parameters of the cluster adsorption isotherm equation and sorbate structure on CNTs, as well as a nonlinear modelling method, was applied. To confirm the cluster nature of amino acid adsorption on CNTs, the clustering criterion proposed in the previous work was applied, and the cluster structure was evaluated, which is significant for the application of CNTs in biomedicine. The found equilibrium parameters of adsorption were applied to the determination of thermodynamic characteristics of adsorption (changes in Gibbs energy, enthalpy and entropy) of L-histidine on CNTs and the character of adsorption was analysed.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"383 ","pages":"Article 113405"},"PeriodicalIF":4.8,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1016/j.micromeso.2024.113406
Ming-Jaan Ho , Kuan-Ying Chen , Minsi Yan , Yun-Ting Chen , Wei-Syuan Jhuang , Ho-Hsiu Chou , Jui-Ming Yeh
In this study, the impact of three distinct cross-linking agents—1,3,5-benzene tricarbonyl trichloride (BTC), tris(4-aminophenyl)amine (TAPA), and 3-aminopropyltrimethoxysilane (APTMS)—on the dielectric and thermal properties of polyimide aerogels was investigated. Poly(amic acid) (PAA) was synthesized by reacting diamine ODA with dianhydride BPDA in NMP, followed by cross-linker introduction in acetic anhydride and pyridine. The analysis reveals that BTC and TAPA, both organic cross-linkers with varying aromatic content, influence the dielectric properties differently. APTMS, an organosilane, introduces inorganic siloxane linkages, enhancing the thermal stability of the aerogels.
Key findings include that BTC-crosslinked aerogels achieved the lowest dielectric constant, 1.215, and dielectric loss, 0.025, making them particularly effective for high-frequency applications. In contrast, TAPA and APTMS-crosslinked aerogels displayed higher dielectric constants and losses. Differential Scanning Calorimetry (DSC) revealed that PI-APTMS exhibited the highest glass transition temperature (Tg), followed closely by PI-TAPA, both significantly higher than the non-crosslinked polyimide aerogel (NAPI), indicating excellent thermal properties. The melting points (Tm) of PI-APTMS and PI-BTC were similar, around 294 °C, attributed to the density of structural stacking. At the same time, PI-TAPA exhibited a lower Tm, likely due to its superior network structure.
Thermogravimetric analysis (TGA) further indicated that PI-TAPA had the highest thermal decomposition temperature (T5d), with all aerogels remaining stable above 420 °C. These results underscore the potential of BTC-crosslinked polyimide aerogels for applications requiring minimal dielectric loss and low constants. We also highlight the influence of organic versus inorganic cross-linkers on thermal and dielectric performance, advancing the field of high-speed communication materials.
本研究调查了三种不同的交联剂--1,3,5-苯三羰基三氯化物（BTC）、三（4-氨基苯基）胺（TAPA）和 3-氨基丙基三甲氧基硅烷（APTMS）--对聚酰亚胺气凝胶介电性能和热性能的影响。聚酰胺（PAA）是通过二胺 ODA 与二酐 BPDA 在 NMP 中反应，然后在乙酸酐和吡啶中引入交联剂合成的。分析表明，BTC 和 TAPA 这两种具有不同芳香族含量的有机交联剂对介电性能的影响各不相同。主要发现包括：BTC 交联气凝胶的介电常数（1.215）和介电损耗（0.025）最低，因此特别适用于高频应用。相比之下，TAPA 和 APTMS 交联气凝胶的介电常数和介电损耗较高。差示扫描量热法（DSC）显示，PI-APTMS 显示出最高的玻璃化转变温度（Tg），紧随其后的是 PI-TAPA，两者均明显高于非交联聚酰亚胺气凝胶（NAPI），表明其具有优异的热性能。PI-APTMS 和 PI-BTC 的熔点（Tm）相似，都在 294 °C 左右，这归因于结构堆叠的密度。热重分析（TGA）进一步表明，PI-TAPA 的热分解温度（T5d）最高，所有气凝胶在 420 ℃ 以上仍保持稳定。这些结果凸显了 BTC 交联聚酰亚胺气凝胶在要求最小介电损耗和低常数的应用中的潜力。我们还强调了有机交联剂和无机交联剂对热性能和介电性能的影响，从而推动了高速通信材料领域的发展。
{"title":"Effect of three distinctive crosslinking agents on the dielectric properties of as-prepared polyimide aerogels prepared from super-critical fluid technique","authors":"Ming-Jaan Ho , Kuan-Ying Chen , Minsi Yan , Yun-Ting Chen , Wei-Syuan Jhuang , Ho-Hsiu Chou , Jui-Ming Yeh","doi":"10.1016/j.micromeso.2024.113406","DOIUrl":"10.1016/j.micromeso.2024.113406","url":null,"abstract":"<div><div>In this study, the impact of three distinct cross-linking agents—1,3,5-benzene tricarbonyl trichloride (BTC), tris(4-aminophenyl)amine (TAPA), and 3-aminopropyltrimethoxysilane (APTMS)—on the dielectric and thermal properties of polyimide aerogels was investigated. Poly(amic acid) (PAA) was synthesized by reacting diamine ODA with dianhydride BPDA in NMP, followed by cross-linker introduction in acetic anhydride and pyridine. The analysis reveals that BTC and TAPA, both organic cross-linkers with varying aromatic content, influence the dielectric properties differently. APTMS, an organosilane, introduces inorganic siloxane linkages, enhancing the thermal stability of the aerogels.</div><div>Key findings include that BTC-crosslinked aerogels achieved the lowest dielectric constant, 1.215, and dielectric loss, 0.025, making them particularly effective for high-frequency applications. In contrast, TAPA and APTMS-crosslinked aerogels displayed higher dielectric constants and losses. Differential Scanning Calorimetry (DSC) revealed that PI-APTMS exhibited the highest glass transition temperature (T<sub>g</sub>), followed closely by PI-TAPA, both significantly higher than the non-crosslinked polyimide aerogel (NAPI), indicating excellent thermal properties. The melting points (T<sub>m</sub>) of PI-APTMS and PI-BTC were similar, around 294 °C, attributed to the density of structural stacking. At the same time, PI-TAPA exhibited a lower T<sub>m</sub>, likely due to its superior network structure.</div><div>Thermogravimetric analysis (TGA) further indicated that PI-TAPA had the highest thermal decomposition temperature (T<sub>5d</sub>), with all aerogels remaining stable above 420 °C. These results underscore the potential of BTC-crosslinked polyimide aerogels for applications requiring minimal dielectric loss and low constants. We also highlight the influence of organic versus inorganic cross-linkers on thermal and dielectric performance, advancing the field of high-speed communication materials.</div></div>","PeriodicalId":392,"journal":{"name":"Microporous and Mesoporous Materials","volume":"383 ","pages":"Article 113406"},"PeriodicalIF":4.8,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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