Applied Clay Science最新文献

{"title":"Photoinduced cooling effect of water-retentive composite of TiO2 and saponite","authors":"Yosuke Kageshima ,&nbsp;Koharu Yagawa ,&nbsp;Katsuya Teshima ,&nbsp;Hiromasa Nishikiori","doi":"10.1016/j.clay.2025.107712","DOIUrl":"10.1016/j.clay.2025.107712","url":null,"abstract":"<div><div>TiO₂ coating of a building envelope is expected to contribute to the mitigation of the heat-island effect because of the photoinduced cooling effect. However, the limited water adsorbability and retentivity of the TiO₂ thin film can require successive sprinkling of water onto a building to achieve the sufficient cooling effect. In this study, a thin film consisting of a mixture of TiO₂ and saponite was prepared through a sol–gel method. The high water retentivity of saponite was found to enhance the photoinduced cooling effect of the TiO₂-based thin film. The photoinduced temporal change in the water adsorbability and retentivity of the highly hydrophilic composite was successfully monitored by using a hydrophilic xanthene dye adsorbed onto the coating as a probe. The effect of environmental humidity on the photoinduced cooling effect was also investigated. We found that higher humidity in the surrounding environment triggered stronger photoinduced cooling effects of the composite film. Especially during summer in Japan, when humidity is high, the TiO₂–saponite composite film did not require intentional water sprinkling to achieve cooling effects.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107712"},"PeriodicalIF":5.3,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101106","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}

{"title":"Kaolinite to smectite transformation: A crystal chemistry study by analytical electron microscopy","authors":"Emilia García-Romero ,&nbsp;Eva Manchado ,&nbsp;Mercedes Suárez","doi":"10.1016/j.clay.2025.107710","DOIUrl":"10.1016/j.clay.2025.107710","url":null,"abstract":"<div><div>Kaolinite and smectite coexist in variable proportions along the Tamame de Sayago deposit in Zamora, Spain, suggesting a close genetic relationship. Kaolinite is formed through the weathering of the Variscan granite, while smectite is subsequently derived from kaolinite through a superimposed hydrothermal process that contributes to Si and Mg content. The transformation of smectites into kaolinite has been widely investigated, however, the reverse transformation of kaolinite into smectite is rarely documented. In this study, a group of representative samples from the deposit were studied via analytical electron microscopy and high-resolution transmission electron microscopy to determine the crystal chemistry of particles and explain the genetic relationship between the two clay minerals. The results showed that the crystal chemistry of particles varied, both among the particles of a sample and at different points within single particles. Chemical composition varied progressively from compositions of kaolinite to kaolinite/smectite and ultimately montmorillonite, with most particles displaying intermediate compositions. SiO₂ and MgO contents increased progressively from kaolinite to montmorillonite through intermediate compositions. The morphologies and compositions of particles suggest the predominance of a solid-state transformation of kaolinite to smectite via interstratified kaolinite-smectite in areas less affected by hydrothermal fluids. Point analyses revealed the existence of domains with different compositions within single pseudohexagonal particles, suggesting the existence of areas with different degrees of transformation in single particles. In areas closer to faults, through which Si and Mg could circulate, dissolution-crystallisation was likely the main process responsible for smectite neoformation. Occasionally, epitaxial smectite growth was observed along the edges of kaolinite crystals. The simultaneous operation but different intensities of three processes solid-state transformation, epitaxy, and dissolution-precipitation generated particles with a complex crystal chemistry related to the existence of interstratified phases.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107710"},"PeriodicalIF":5.3,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101109","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}

{"title":"Hydrocalumite and hydrocalumite-type compounds: A special type of layered double hydroxides","authors":"Alejandro Jiménez ,&nbsp;Raquel Trujillano ,&nbsp;Antonio Gil ,&nbsp;Vicente Rives ,&nbsp;Miguel Ángel Vicente","doi":"10.1016/j.clay.2025.107707","DOIUrl":"10.1016/j.clay.2025.107707","url":null,"abstract":"<div><div>An exhaustive bibliographical review of one of the most peculiar Layered Double Hydroxides, LDH, namely hydrocalumite and hydrocalumite–type compounds, has been carried out. The main differences that make hydrocalumite a special and interesting LDH are described, as well as the main methods of synthesis. A comprehensive comparison is also made with respect to MgAl–carbonate hydrotalcite with a Mg/Al molar ratio of 2. Thermal behavior of hydrocalumite is also different than that of other LDH, leading to the formation of attractive Mixed Metallic Oxides, MMO. Thus, the applications of hydrocalumite, hydrocalumite–type compounds and the derived MMO in environmental remediation and heterogeneous catalysis and photocatalysis are presented. Hydrocalumite, contrary to hydrotalcite, is not currently commercialized on an industrial scale, probably because its preparation is more complicated. Considering the excellent properties of hydrocalumite and the price, abundance and biocompatibility of its components, the scaling of its production should be a key challenge to take advantage in its industrial application.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"267 ","pages":"Article 107707"},"PeriodicalIF":5.3,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143101107","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}

{"title":"Multi-functional nanoarchitectonics of allophane via addition reactions with acrylonitrile through C-O bond formation","authors":"Qingcheng Zhang,&nbsp;Qingbin Xie,&nbsp;Mohammad Fahimizadeh,&nbsp;Meiqing Chen,&nbsp;Yuchen Diao,&nbsp;Weisen Cai,&nbsp;Peng Yuan","doi":"10.1016/j.clay.2025.107706","DOIUrl":"10.1016/j.clay.2025.107706","url":null,"abstract":"<div><div>Organic functional groups, such as the cyano group (-CN), were introduced onto the Allophane (Allo) surface through addition reactions to achieve precise control over Allo surface properties. Polyacrylonitrile (PAN), Allo and surface-treated Allo were characterized using FT-IR, XRD, XPS and ²⁷Al NMR techniques. It was found that an additional reaction occurs between Allo and acrylonitrile (AN), forming a C-O covalent bond between the unsaturated carbon‑carbon bonds (C=C) of AN and the aluminum hydroxyl groups (Al-OH) on the Allo surface. This reaction constructs an (Al)O-C(C) structure, rearranging the electron density in the aluminum‑oxygen octahedral units, thereby affecting the short-range quasi-crystalline structure within Allo. Concurrently, -CN groups were attached to the Allo surface, while alkenes such as acrylic acid and sodium acrylate introduced organic functional groups like -COOH and -CONH₂ onto the Allo surface. This approach provides a new method for grafting functional groups onto the Allo surface and a novel strategy to modify the surface properties of Allo to obtain multifunctional, high-performance Allo nanocomposite materials.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"266 ","pages":"Article 107706"},"PeriodicalIF":5.3,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137571","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}

{"title":"Surfactant mediated intercalation of a hydrophobic drug into layered double hydroxides: Probing the structural features by the photophysical behaviour of piroxicam","authors":"Nawal Fodil Cherif ,&nbsp;François Réveret ,&nbsp;Anthony Barros ,&nbsp;Vagner Roberto Magri ,&nbsp;Fabrice Leroux ,&nbsp;Damien Boyer ,&nbsp;Vera Regina Leopoldo Constantino ,&nbsp;Christine Taviot-Guého","doi":"10.1016/j.clay.2025.107708","DOIUrl":"10.1016/j.clay.2025.107708","url":null,"abstract":"<div><div>Piroxicam (PIR), a hydrophobic drug with ionisable properties, can adopt various prototropic forms and conformations, which make its structural and dynamic properties highly dependent on its environment. In this study, PIR was, for the first time, incorporated into Zn²⁺/Al³⁺ layered double hydroxides using a surfactant-mediated intercalation method (Zn₂Al-DS_@%PIR), which first involved the encapsulation of PIR within dodecyl sulfate (DS) micelles. A comprehensive investigation of the DS-PIR assembly within the interlayer space of the LDH is proposed, particularly emphasizing the utilization of the optical properties of PIR as a structural probe. The structural and chemical properties of the Zn₂Al-DS_@%PIR samples prepared with different PIR contents (0.16, 0.90 and 2.06 wt%) were assessed by X-ray diffraction, Fourier transform infrared (FTIR) and thermal analysis. By exploiting PIR's photochemical properties in both solid-state and solution, it was gained deeper insights into PIR molecular arrangement within the LDH interlayer space. FTIR results showed the stabilization of the ZZZ conformation form for intercalated PIR, while thermal analyses revealed an improved thermal stability of PIR of 80 °C for the sample with a maximum PIR loading content of 2.06 wt%. Interestingly, fluorescence results clearly confirmed the intercalation of PIR in LDH, both as global neutral and anionic forms, and allowed to infer their location in the interlayer space. A protective effect against photodegradation was also observed. This work can contribute to advancements in the challenging intercalation of other hydrophobic drugs.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"266 ","pages":"Article 107708"},"PeriodicalIF":5.3,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137572","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}

{"title":"Mechanochemical activation of non-conventional precursors for use as suplementary cementitious materials","authors":"A. Seco ,&nbsp;M.A. Martín-Antunes ,&nbsp;S. Espuelas ,&nbsp;A. Fernández ,&nbsp;E. Prieto","doi":"10.1016/j.clay.2025.107705","DOIUrl":"10.1016/j.clay.2025.107705","url":null,"abstract":"<div><div>This work analyzes the effect of Mechanochemical Activation (MA) of a Commercial low-grade kaolinite and low-grade illite, a feldspar, a diatomite and a clayey soil (non-commercial) as supplementary cementitious materials. Milling was conducted at different times for up to 360 min. MA decreased the particles size and increased the specific surface area except for low-grade illite. However, prolonged milling produced agglomeration in feldspar, diatomite and clayey soil. MA partially reduced diffractogram peaks and modified the dehydroxylation losses of mass in the thermogravimetric tests. MA's effect over the solubility of SiO₂ and Al₂O₃ was not conclusive, with differences among aluminosilicate minerals and with no relationships with their physical parameters or chemical structures. Feldspar was the only one not to show Strength Activity Index (SAI) increases due to MA. Low-grade illite, feldspar and diatomite combinations surpassed 75 % on the SAI. No clear relationships were observed between the combinations SAI and their physical parameters, chemical structure or SiO₂ and Al₂O₃ availability.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"266 ","pages":"Article 107705"},"PeriodicalIF":5.3,"publicationDate":"2025-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137570","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}

{"title":"Combined effect of 2D nature and structural glass behaviour and true magnetic contribution to the low-temperature heat capacity of layered double hydroxides","authors":"V. Tkáč ,&nbsp;Yu.G. Pashkevich ,&nbsp;E.L. Fertman ,&nbsp;R. Tarasenko ,&nbsp;E. Čižmár ,&nbsp;A. Feher ,&nbsp;A.V. Fedorchenko ,&nbsp;C.S. Neves ,&nbsp;D.E.L. Vieira ,&nbsp;A.N. Salak","doi":"10.1016/j.clay.2024.107695","DOIUrl":"10.1016/j.clay.2024.107695","url":null,"abstract":"<div><div>Heat capacity of cobalt-aluminium and magnesium-aluminium layered double hydroxides (LDH) with the divalent-to-trivalent cations ratio (<em>n</em>) of 2 and 3, and intercalated with NO₃⁻, CO₃²⁻ and OH⁻, was measured as a function of temperature between 2 and 100 K. Magnetic contribution to the heat capacity (<em>C</em>_mag) of Co_<em>n</em>Al LDH was extracted from comparison of the <em>C</em>(<em>T</em>) dependences with the respective reduced dependences of their non-magnetic counterparts, Mg_<em>n</em>Al LDH. At the lowest measured temperatures, the magnetic contribution to the heat capacity (<em>C</em>_mag) of Co-containing LDH was found to be almost two orders of magnitude bigger than their lattice contribution. In a zero magnetic field, the low-temperature <em>C</em>_mag of Co₂Al LDH was measured to be proportional to <em>T</em>^2.6, while for Co₃Al LDH, <em>C</em>_mag ∼ <em>T</em>² was observed. An application of an external magnetic field was revealed to converge these dependences to <em>C</em>_mag ∼ <em>T</em>³ in compounds with both <em>n</em> = 2 and 3. However, the conversion in Co₂Al LDH occurred at lower values of external magnetic field (50 kOe) than that in Co₃Al LDH (90 kOe).</div><div>It was revealed from the <em>C</em>(<em>T</em>) behaviour of the non-magnetic LDH at the lowest measured temperatures that they possess the features typical for both a 2D solid and a structural glass. The reduced <em>C</em>(<em>T</em>)/<em>T</em>³ heat capacity of Mg_<em>n</em>Al LDH intercalated with nitrate was found to demonstrate a so-called boson peak, which is a manifestation of a glassy state. The observed low-temperature structural glassy state in LDH was associated with the disorder of the intercalated species.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"266 ","pages":"Article 107695"},"PeriodicalIF":5.3,"publicationDate":"2025-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137596","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}

{"title":"Performance and mechanism of the controllable gaseous ClO2 generation with modified sepiolite-based porous materials","authors":"Nana Chang ,&nbsp;Wanting Li ,&nbsp;Mingming Fei ,&nbsp;Min Tie ,&nbsp;Hao Ling ,&nbsp;Yunlei Zhao ,&nbsp;Xiayi Hu","doi":"10.1016/j.clay.2024.107692","DOIUrl":"10.1016/j.clay.2024.107692","url":null,"abstract":"<div><div>ClO₂ is a strong oxidizing fungicide widely used to protect people from bacterial diseases. It is of great urgency to develop a safe, fast and easy-to-use ClO₂-based antimicrobial material to safeguard people's lives and health. In this work, the cheap natural porous ore sepiolite is adopted and modified by FeCl₃ and AlCl₃ as acidic activators. Several characterizations suggested the unchanged morphology and bond structure but the enlarged pore size improved the ClO₂-releasing amount, which could reach to 13,903 μg with 25 % FeCl₃-sepiolite and 12,670 μg with 15 % AlCl₃-sepiolite. The separated FeCl₃/AlCl₃-sepiolite and NaClO₂-sepiolite effectively extended the ClO₂ releasing life. Meanwhile, increased temperature and humidity were beneficial for enhancing the ClO₂ releasing amount. The mechanism investigation confirmed the ambient moisture promoted the contact to achieve ClO₂ generation reactions. The above results showed that the well-developed metal chloride modification in sepiolite exhibits a good prospects in terms of industry and environment.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"266 ","pages":"Article 107692"},"PeriodicalIF":5.3,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137592","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}

{"title":"Rare earth modification of smectites and their use in luminescent up-conversion emission","authors":"M. Čičkan ,&nbsp;R. Klement ,&nbsp;M. Matejdes ,&nbsp;V. Kureková ,&nbsp;D. Furka ,&nbsp;S. Furka ,&nbsp;K. Tomanová ,&nbsp;P. Veteška ,&nbsp;M. Janek","doi":"10.1016/j.clay.2024.107685","DOIUrl":"10.1016/j.clay.2024.107685","url":null,"abstract":"<div><div>The spectroscopic response of synthetic smectites after cation exchange with selected rare earth elements (REE) in the UV-VIS region was investigated for luminescence activity. Hectorite (Optigel SH) and Sumecton (Sumecton-SA), both swellable smectites, underwent modification through exchange reactions using Er³⁺ and equimolar mixture of Er³⁺/Yb³⁺ cations. REEs were chosen for their optical activity, stemming from multiple 4f-4f electron orbital levels and excitation/deexcitation transitions induced in the UV-VIS region. The optical responses of raw and modified smectites were verified after heating of exchanged samples up to temperatures of 400 °C, 800 °C, and 1200 °C for 1 h, to synthesize new optically active materials. Efficient up-conversion was observed in samples heated at 1200 °C, exhibiting characteristic green ∼525 and 550 nm, ²H_11/2/⁴S_3/2 → ⁴I_15/2 and red ∼660 nm, ⁴F_9/2 → ⁴I_15/12 emissions, due to new phases formed from smectite-REE matrices. The X-ray diffraction and scanning electron microscopy analysis confirmed the presence of the Er₂Si₂O₇ and/or Yb₂Si₂O₇ phase. The presence of REE cations induced homogeneous growth of ∼100 to 300 nm large crystals found by scanning electron microscopy in Sumecton, while larger crystal particle size distribution up to 5 μm particles were found for the REE modified Hectorite.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"266 ","pages":"Article 107685"},"PeriodicalIF":5.3,"publicationDate":"2025-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137595","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}

{"title":"Layer double hydroxide (LDH): Synthesis and incorporation in alkoxysilanes for stone conservation","authors":"B.A. Silva ,&nbsp;S. Piçarra ,&nbsp;A.P. Ferreira Pinto ,&nbsp;M.F. Pereira ,&nbsp;M. Rucha ,&nbsp;M.F. Montemor ,&nbsp;B. Sena da Fonseca","doi":"10.1016/j.clay.2024.107687","DOIUrl":"10.1016/j.clay.2024.107687","url":null,"abstract":"<div><div>Layer double hydroxides (LDH) carry potential as additives for modifying alkoxysilanes in building materials conservation due to their unique ability to exchange ions with the surrounding environment. This paper reported, for the first time, the potential benefits of CaAl-LDH (LDH-S) prepared by the co-precipitation method as additives in alkoxysilanes for stone consolidation. The LDH prepared in this work were compared with commercial CaAl-LDH (LDH-C). Both additives revealed high crystallinity and purity; however, LDH-S had larger dimensions (approximately 85 vs 55 nm) and formed agglomerates upon drying. While consolidants containing LDH additions above 0.5 % (<em>w</em>/<em>v</em>) showed increased viscosity and susceptibility to cracking, concentrations up to 2 % did not compromise the penetration of the alkoxysilane oligomers into stone pores or significantly jeopardized their capacity to strengthen the stone in depth. At higher concentrations, both LDH tended to accumulate on the surface of the stone investigated (limestone with pores of approximately 0.8 μm). Contrarily, the smaller LDH-C, at lower concentrations (0.125 % to 0.5 %), demonstrated a viable incorporation with adequate distribution over the surface. The incorporation of LDH into alkoxysilanes mitigated the formation of hard crust; prevented siloxanes accumulation near the surface and minimized adverse effects on the appearance of light-coloured stones. These findings indicate that the incorporation of small amounts of LDH into alkoxysilanes consolidants is viable and paves the way for introducing new functionalities into diverse conservation treatments since LDH can carry antifouling or biocide agents.</div></div>","PeriodicalId":245,"journal":{"name":"Applied Clay Science","volume":"266 ","pages":"Article 107687"},"PeriodicalIF":5.3,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143137593","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}