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Advanced functional two‐dimensional (2D) nanomaterials offer unique advantages in drug delivery systems for disease treatment. Kaolinite (Kaol), a nanoclay mineral, is a natural 2D nanomaterial because of its layered silicate structure with nanoscale layer spacing. Recently, Kaol nanoclay is used as a carrier for controlled drug release and improved drug dissolution owing to its advantageous properties such as surface charge, strong biocompatibility, and naturally layered structure, making it an essential development direction for nanoclay‐based drug carriers. This review outlines the main physicochemical characteristics of Kaol and the modification methods used for its application in biomedicine. The safety and biocompatibility of Kaol are addressed, and details of the application of Kaol as a drug delivery nanomaterial in antibacterial, anti‐inflammatory, and anticancer treatment are discussed. Furthermore, the challenges and prospects of Kaol‐based drug delivery nanomaterials in biomedicine are discussed. This review recommends directions for the further development of Kaol nanocarriers by improving their physicochemical properties and expanding the bioapplication range of Kaol. [ABSTRACT FROM AUTHOR]

Excellent inflammation suppression and wound healing using calcined kaolinite have been achieved. Mechano-bactericidal interactions between bacteria and nanoclay change the structure of the phospholipid bilayers of the cell membrane and in turn affect the biochemical functions of bacterial exosomes. The inflammation response was inhibited and wound healing was enhanced due to the mechano-bactericidal interactions. [ABSTRACT FROM AUTHOR]

The increasing prevalence of antimicrobial resistance (AMR), particularly among Gram-negative organisms, has led to a significant challenge in treating infections with antibiotics. Despite the long-term efforts to explore antibacterial agents or drugs, potentiating antibacterial activity while minimizing toxicity to human health remains a significant challenge. In this study, zinc-kaolinite composites were prepared using the calcination method to achieve effective and selective antibacterial activity while maintaining non-toxicity to mammalian cells. The interfacial interactions between kaolinite and zinc ions resulted in the immobilization of the latter by cation-π interaction and polar interactions. This led to a disordered structure and different geometrical configurations at the interface, with the spatial coefficient of the zinc ions changing from 0.64 to 2.08. Furthermore, the interfacial interactions regulate the intrinsic mobility and dissolution rates of zinc ions in solution, resulting in the controlled release of zinc ions. Moreover, a well-oriented structure and steady-flow rheological behaviors enable zinc-kaolinite composites to search for bacteria, thereby achieving selective antibacterial activity. The release behavior of zinc ions at the site of the bacterial surrounding environment significantly reduces toxicity and side effects. The comprehensive investigation of interfacial interaction and antibacterial performance provides new perspectives for the development of metal ion-based antibacterial materials in public health environments. Zinc ion diffusion is controlled by interfacial interactions of nanoclay-metal ions for high delivery and selectivity, continuous action over long contact times, reduced toxicity, and efficient antimicrobial activity. [Display omitted] • The controlled release of zinc ions was achieved by interfacial interactions. • The kaolinite particles in solution could form a well-oriented network in space. • The antibacterial activity was affected by the geometrical and rheological behaviors. • The selectivity was achieved by double-layer forces with no toxicity to mammalian cells. [ABSTRACT FROM AUTHOR]

Engineered nanoparticle–support interaction is an effective strategy for tuning the structures and performance of engineered nanoparticles. Here, we show that tuning the dehydroxylation of kaolinite nanoclay as the support could induce zinc oxide–kaolinite interactions. We used free energy theory, electron microscopy, and X-ray photoemission spectroscopy to identify interaction strengths between metal oxides and the underlying nanoclay induced by dehydroxylation. Desirable exposure of nanoparticle sites and the geometrical and crystal structure were obtained by tuning the interface interactions between ZnO nanoparticles and nanoclay. The surface free energy of zinc oxide–nanoclay results in different interfacial interactions, and the properties of the surface free energy electron-donating (γ−) and electron-accepting (γ+) parameters have significant effects on the electron acceptor. This could, in turn, promote stronger interactions between zinc oxide and the kaolinite surface, which produce more active (0001) Zn-polar surfaces with promoting zinc oxide nanoparticles growing along the <0001> direction. Reactive oxygen species, leached zinc ions, and electron transfer can modulate the antibacterial activities of the samples as a function of interface free energy. This further demonstrates the interfacial interactions induced by dehydroxylation. This work has new application potential in biomedicine and materials science. [ABSTRACT FROM AUTHOR]

Death from acute hemorrhage is a major problem in military conflicts, traffic accidents, and surgical procedures, et al. Achieving rapid effective hemostasis for pre-hospital care is essential to save lives in massive bleeding. An ideal hemostasis material should have those features such as safe, efficient, convenient, economical, which remains challenging and most of them cannot be achieved at the same time. In this work, we report a rapid effective nanoclay-based hemostatic membranes with nanoclay particles incorporate into polyvinylpyrrolidone (PVP) electrospun fibers. The nanoclay electrospun membrane (NEM) with 60 wt% kaolinite (KEM1.5) shows better and faster hemostatic performance in vitro and in vivo with good biocompatibility compared with most other NEMs and clay-based hemostats, benefiting from its enriched hemostatic functional sites, robust fluffy framework, and hydrophilic surface. The robust hemostatic bandages based on nanoclay electrospun membrane is an effective candidate hemostat in practical application. Rapid, easy and effective haemostasis is needed to reduce the loss of life from traumatic haemorrhage. Here, the authors report on the creation of polymer-nanoclay electrospun membranes and demonstrate haemostatic effects showing superior effects to other clay based haemostats. [ABSTRACT FROM AUTHOR]

Abstract: Uncontrolled bleeding following trauma is associated with a high risk of death. Here, an emerging kaolinite nanoclay composite (iron oxide‐kaolinite, α‐Fe2O3‐kaolinKAc) is developed, based on the natural hemostat hematitum used in traditional Chinese medicine to effectively control hemorrhage. α‐Fe2O3‐kaolinKAc stops bleeding in ≈183 ± 16 s and exhibits higher hemostatic activity than the related compounds FeOOH‐kaolinKAc (298 ± 14 s), γ‐Fe2O3‐kaolinKAc (212 ± 11 s), and Fe3O4‐kaolinKAc (218 ± 15 s). This rapid effect is attributed to efficient absorption of the fluid in blood, activation of blood platelets, and induction of the coagulation cascade by kaolinite and the aggregation of red blood cells induced by α‐Fe2O3. α‐Fe2O3‐kaolinKAc shows slight hemolysis (<0.11%) as compared to kaolinite (30%), which accelerates wound healing. The biocompatibility, hemostatic activity, and low cost of α‐Fe2O3‐kaolinKAc make it a safe and effective agent for preventing massive blood loss after traumatic injury. [ABSTRACT FROM AUTHOR]

Kaolinite (Kaol) was intercalated with dimethyl sulfoxide (DMSO) and subsequently methanol (MeOH) to prepare intercalation compounds Kaol-DMSO and Kaol-MeOH. Kaol-MeOH was used as an intermediate to synthesize Kaol-sodium dodecyl sulfate (SDS) intercalation compound (Kaol-SDS) via displacement reaction. The ultrasonic exfoliation of Kaol-SDS produced a resultant Kaol-SDS-U. The samples were characterized by X-ray diffraction (XRD), Fourier transformation infrared spectroscopy (FTIR), thermal analysis, scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and particle size analysis. The results revealed that the intercalation of sodium dodecyl sulfate into kaolinite layers caused an obvious increase of the basal spacing from 0.72-4.21 nm. The dehydroxylation temperature of Kaol-SDS was obviously lower than that of original kaolinite. During the intercalation process of sodium dodecyl sulfate, a few kaolinite layers were exfoliated and curled up from the edges of the kaolinite sheets. After sonication treatment, the kaolinite layers were further transformed into nanoscrolls, and the exfoliated resultant Kaol-SDS-U possessed a smaller particle size close to nanoscale. [ABSTRACT FROM AUTHOR]

Clay mineral and its derivatives can play an important role in stabilizing functional- groups and nanostructures. Here, a TP-SiNSs (TiSi2O5(OH)2·(OH2)2) nanocomposite, with highly dispersed and stabilized TiO2 precursor (TP, Ti(OH)4 gel) on template-free 2D silica nanosheets (SiNSs, Si2O3(OH)2), is presented, which is derived from kaolinite, a natural 2D layer mineral. Unique lead sorption behaviors are observed for balanced hydrophobicity-hydrophilicity, short sorption equilibrium time (within 5 min), large applied sorption capacities (≈38 000 kg polluted drinking water per kg TP-SiNSs, effluent Pb(II) contents <10 µg L-1), and excellent renewability. The highly dispersed surface titanium hydroxyl groups, together with 2D hierarchical porous nanostructure of TP-SiNSs effectively facilitate the selective adsorption of Pb(II) ions, inhibit the pore blockage after Pb(II) adsorption, and prolong the service life. The detailed adsorption mechanism as a function of pH value and ion concentration is clarified by density functional theory (DFT) calculations, and the higher adsorption selectivity of TP-SiNSs for Pb(II) over Ca(II) and Mg(II) is attributed to surface complex on TP-SiNSs, which induces strong bonding between Pb(II) and titanium hydroxyl groups. The interface geometry and electronic structure calculations demonstrate that the stabilized and spatially distributed titanium hydroxyl group on TP-SiNSs can greatly enhance the surface adsorption ability. [ABSTRACT FROM AUTHOR]

In this work, a series of transition metal (Cr, Mn, Fe, and Co) doped kaolinite nanoclays were investigated by density functional theory (DFT) calculations. The influence of metal doping on geometric structure and electronic structure of kaolinite was analyzed. The ferromagnetic (FM), antiferromagnetic (AFM), and nonmagnetic (NM) states of transition metal (TM) doped kaolinite structures were studied. The crystal volume, lattice parameters, bond length, charge, and spin were calculated by dispersion-corrected density functional theory (DFT-D2). The results indicated that Cr and Fe dopants showed more stable under AFM state, while Mn preferred both AFM and FM states, and Co dopant preferred NM state. Also, the transition metal doping could induce lattice volume expansion and some dopant states in the band gap. [ABSTRACT FROM AUTHOR]

An enhanced antibacterial activity of Fe2O3 nanoparticles was achieved by controlling the distribution density of Fe2O3 nanoparticles on modified kaolinite nanosheets (Fe2O3–KlnKAc) by adjusting the pH value of the reaction system. A proper distribution density of Fe2O3 nanoparticles generating higher levels of hydroxyl radicals led to a higher antibacterial activity. [ABSTRACT FROM AUTHOR]

A composite phase-change material (PCM) consisting of a binary organic mixture of capric-lauric acid and coal-series kaolinite (Kc) as was prepared by vacuum impregnation. Dimethyl sulfoxide was used as intercalation agent to increase the interlayer Kc space, enhancing the storage energy density of the composite PCM. Capric (CA) and lauric (LA) acids were inserted into the interlayers of the Kc intercalation complexes (I-Kc). The chemical structure and thermal properties of the composite PCM were characterized in detail. The thermal performance of the corresponding cement paste composite PCM panel was also evaluated. The latent heat of the CA-LA/I-Kc was 42.36 J g−1 at a melting temperature of 16.96 °C at a CA-LA content of 36.93 %. The melting temperature of the composite PCM changed to −0.33 °C and the latent heat storage capacity to 0.22 J g−1 after one month of thermal cycling, which shows the excellent thermal reliability of the composite PCM and potential application for thermal energy storage in energy-efficient buildings. [ABSTRACT FROM AUTHOR]

A preparation strategy for constructing Pd-deposited ZnO/kaolinite was described in detail in this paper. Natural rod-like kaolinite served as a support to disperse ZnO nanoparticles through a thermal treatment. The ZnO nanoparticles were assembled on the surface of kaolinite rods to produce ZnO/kaolinite nanocomposites, which were then employed as a supporting material for the dispersion of Pd nanoparticles. The samples were characterized by XRD, FTIR, TEM, XPS, UV–vis spectroscopy, and photocatalytic property measurements. The results indicated that an obvious chemical binding existed between ZnO nanoparticles and the kaolinite surface. The shift of the binding energy of metallic Pd demonstrated a strong interaction between the metallic Pd and ZnO nanocrystals. The as-synthesized Pd–ZnO/kaolinite exhibited superior photocatalytic activity for the photodegradation of methylene blue compared with Pd/ZnO, ZnO/kaolinite, and pure ZnO, which indicated that the hybridization of the metal, kaolinite rods, and semiconductor could provide enhanced photocatalytic activity through a synergistic effect. [ABSTRACT FROM AUTHOR]

Antimony doped tin oxide nanoparticles (Sb–SnO2) were uniformly coated on the surfaces of rod-/flake-like kaolinites (Kaol) to synthesize kaolinite-based conductive powders (Sb–SnO2)Kaol, which was then added into polypropylene (PP) matrix to produce conductive (Sb–SnO2)Kaol–PP nanocomposites. The effects of (Sb–SnO2)Kaol characteristics on the volume resistivity and mechanical properties of (Sb–SnO2)Kaol–PP were in detail investigated. The results indicated that surface-modified (Sb–SnO2)Kaol could improve the dispersion in PP matrix, and the as-synthesized nanocomposites showed better electrical property than that without surface modification. The volume resistivity of (Sb–SnO2)Kaol–PP reached 7.3×108 Ω·cm at the (Sb–SnO2)Kaol concentration of 40%, 6–7 order of magnitude lower than that of pure PP. The as-synthesized (Sb–SnO2)Kaol–PP nanocomposites could show potential applications in the conductive fields. [ABSTRACT FROM AUTHOR]

Abstract: The physicochemical aspects of four soft kaolins were investigated using X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electron microscopy (TEM), Fourier transformation infrared spectroscopy (FTIR), differential scanning calorimetry-thermogravimetry (DSC-TG) specific surface area and surface zeta potential measurements. The correlation between degree of crystal order, thermal stability, morphology and surface characteristics of the kaolinites were examined and discussed. The endothermic peak temperatures, in particular, showed a clear positive correlation with the calculated crystallinity index of the kaolinites. The physicochemical characteristics of a natural kaolinite rod were considered in greater detail. Rod-like kaolinite had lower degree of order and zeta potential (pH<3) than the platy kaolinites but was more ordered than expected for halloysite, and did not show a distinct central void. A schematic morphology for the proposed arrangement of curved kaolinite layers making up the rods is presented. [Copyright &y& Elsevier]

In this article, we reported the synthesis of novel Sb-SnO/kaolinite (SK) nanocomposites by assembling antimony-doped tin oxide (ATO) nanoparticles on the surface of kaolinite rods without addition of dispersant. The samples were characterized by X-ray diffraction, transmission electron microscopy (TEM), high-resolution TEM, X-ray photoelectron spectroscopy (XPS), and N adsorption-desorption techniques. The crystal size and loading density of ATO nanoparticles onto kaolinite rods could be controlled through the synthetic conditions. The color and resistivity of the composites varied with the loading density of ATO nanoparticles. Investigations of the interfacial binding between ATO layer and rod surface indicated that surface characteristics could facilitate the deposition of various metal oxides nanoparticles. XPS analysis demonstrated that the entrance of Sb into SnO crystallite led to the improvement of conductivity and the color change of the composites. The formation mechanism for SK composites was also discussed. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we reported the synthesis of composite conductive powders of antimony-doped tin oxide (Sb–SnO2) coated onto kaolinite. Structure and morphology of the samples were systematically characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), Fourier transform infrared (FTIR) and X-ray photoelectron spectrum (XPS). The results showed that Sb–SnO2 nanoparticles (<10nm) were successfully coated as thin layers on the surface of kaolinite. The antimony-doped tin oxide/kaolinite (ATK) composites retained the flake morphology like the original kaolinite and had a resistivity of 273.2Ω·cm. Sb–SnO2 layers were proved to attach to the kaolinite surface via the Sn–O–Si or Sn–O–Al bonds. The growth mode of Sb–SnO2 layers onto the kaolinite was investigated. [Copyright &y& Elsevier]

Nanoclay materials have a wide range of industrial applications. The structural design of kaolinite (Kaol) is beneficial to expand its application and improve the high value-added utilization. In this review, we have discussed how the Density Functional Theory (DFT) and molecular dynamics (MD) calculations were used to explain the molecular structure of nanoclay materials during structural design and the constitutive relationships for application. With some specific examples here, the structures of Kaol (bulk, edges and the thermodynamic structures), the adsorption of molecules (water, hydrated cations, organic molecules and the mixtures) on the surface of Kaol, the intercalation of small and macro molecules into layers of Kaol, the interfacial hybridization of Kaol, and the doping structures of Kaol performed with DFT and MD were reviewed and discussed in details. This work can give a reference for the calculation of all nanoclay materials, even extend to other two-dimensional layered materials. We have also pointed out the challenges and potential future perspectives associated with DFT and MD in this field. The molecular structure of nanoclay materials during structural design and the constitutive relationships for application were discussed with Density Functional Theory (DFT) and molecular dynamics (MD) calculations. Challenges and potential future perspectives of Kaol with DFT and MD were also pointed out. This work can give a reference for the calculation of all nanoclay materials, even extend to other 2D materials. [Display omitted] • Molecular structures of modified kaolinite were reviewed with DFT and MD • Constitutive relationships of modified kaolinite were reviewed with DFT and MD • Challenges and prospects of kaolinite with DFT and MD were pointed out • It's a reference for the calculation of other nanoclays and 2D materials [ABSTRACT FROM AUTHOR]

Reactive oxygen species (ROS) releasing materials are increasingly used in nanomedicines due to their effectiveness against a broad spectrum of microbes. However, most ROS‐releasing materials rely on external stimuli such as photoirradiation, either through photodynamic or photocatalytic processes, which limits their practical applications. Herein, this work presents a novel nanoclay mediated self‐promoted ROS releasing material called oxygen vacancies‐rich ZnO/kaolinite (Ov‐rich ZnO/Kaol). Both experiments and density functional theory (DFT) calculations reveal that the introduction of kaolinite increases the content of Ov in ZnO, and the change in the electronic structure promotes the process of oxygen adsorption and activation, resulting in the generation of ·O2−through oxygen reduction without photoirradiation. Molecular dynamics simulations confirm that Ov enhances the interaction between the material and bacterial membrane, promoting the bacterial‐killing effect of ·O2−. More importantly, Ov‐rich ZnO/Kaol is successfully prepared on a pilot scale and used to manufacture antibacterial gauze, which showed at least 99% antibacterial activity against both Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) in the absence of light. The as‐prepared material also exhibited satisfactory biocompatibility and biosafety. This method can offer a more benign approach to address the limitations of traditional photoirradiation‐dependent photosensitizers for antimicrobial gauze. [ABSTRACT FROM AUTHOR]

Building on Concrete Results with Phase‐Change Materials: A composite phase‐change material (PCM) consisting of coal‐series kaolinite (Kc) and a binary organic mixture of capric–lauric acid was prepared by vacuum impregnation, as described in the Full Paper on page 77 by Huaming Yang and Songyang Liu of Central South University in Changsha, China. Dimethyl sulfoxide was used as an intercalation agent to increase the interlayer Kc space, thereby enhancing the storage energy density of the composite. The composite shows improved thermal reliability and chemical stability in comparison to previous results, and the technology could be used to help reduce indoor temperature and energy consumption. [ABSTRACT FROM AUTHOR]

Hierarchical porous SiO 2 -AlOOH composite nanosheets (HPSA) with a three-dimensional (3D) structure were prepared from two-dimensional (2D) layered mineral kaolinite (A1 2 Si 2 O 5 (OH) 4 ) via a template-free structural reorganization method. The obtained material was subjected to homogeneous and effective amino-functionalization by grafting it with (3-aminopropyl) triethoxysilane. Owing to the enhanced 3D hierarchical meso-macroporous structure containing highly dispersed protonated amino groups ( NH 3 + ), the as-prepared amino-functionalized HPSA (NH 2 -HPSA) showed unique adsorption performance towards the congo red anionic dye. It provides feasibilities to fabricate other functional hierarchical porous materials from clay minerals, which can offer potential applications in adsorption, separation, catalysis and other environmental remediation fields. [ABSTRACT FROM AUTHOR]

Thermal energy storage using phase change materials is considered as a significant strategy for relieving the energy crisis. Herein an emerging paraffin-based composite form-stable phase change material (FSPCM) was fabricated using carbon-coated nanoscroll (CAN) as supporting material prepared via in-situ carbonizing the delaminated kaolinite (Kaol). The effect of carbonization temperature on the thermal performance of composite FSPCM was investigated. The samples were characterized using XRD, FTIR, DSC, XPS, SEM, TEM, TG, and nitrogen adsorption-desorption isotherms. The results indicated that the pore properties of the exfoliated and carbonized Kaol significantly increased, which was beneficial to the high loading and leakage-proof. The optimum paraffin content of CAN composite FSPCMs without leakage is 60.63%, 63.14%, and 59.99% for calcination at 600 °C, 700 °C, and 800 °C, respectively. Paraffin/CAN composite FSPCMs have the phase temperatures of 51–58 °C and high latent heat of 123–142 J/g. Compared with pure paraffin, the thermal conductivities of paraffin/CAN composite FSPCMs were increased by 1.98, 1.92, and 2.01 times for calcination at 600 °C, 700 °C, and 800 °C, respectively. The composite FSPCMs exhibit excellent thermal and chemical stability after 1000 thermal cycles, indicating that paraffin/CAN composite FSPCMs have excellent potential in the solar energy storage system. Image 1 • Carbon-coated nanoscroll was prepared via delaminating and carbonizing kaolinite. • Loading of paraffin in nanoscroll reaches up to 63.14% without leakage. • Paraffin/CAN composite PCMs show good chemical stability and reliability. • Thermal conductivity of composite PCMs was enhanced by around 2 times. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Ag nanoparticles (AgNPs) of 1.6 ∼ 4 nm were assembled on 2D silica nanosheets (SiNSs). • Sn(II) species in AgNPs/SiNSs can effectively guarantee the stability of AgNPs. • AgNPs/SiNSs showed enhanced catalytic reduction reaction over 4-nitrophenol. Abstract A facile, environment-friendly route is illustrated for the efficient assembly of stable and uniform silver nanoparticles (AgNPs) on the surface of two-dimensional (2D) silica nanosheets (SiNSs, derived from natural kaolinite mineral) via in-situ reduction using Sn(II) as reductant. Compared to the common reduction method using NaBH 4 reductant, the loaded AgNPs on AgNPs/SiNSs nanocomposite showed higher purity, uniformity and stability (antioxygenation). The catalytic reduction of 4-nitrophenol (4-NP) over AgNPs/SiNSs nanocatalyst was almost complete within 40 s without stirring and the apparent kinetic rate constant k app (80.19 × 10−3 s−1) is much higher than those of other substrate-supported Ag/Au nanocatalysts. The effects of support material and assembly approach of AgNPs on the catalytic performance were discussed in detail. The high turnover frequency (TOF) for AgNPs/SiNSs nanocatalyst (3.52 min−1) indicates that the high-density dispersion of uniform small-sized AgNPs on 2D SiNSs surface is responsible for the excellent catalytic property, which offer many active sites for effective contact with the reactants and fast interfacial electron transfer from the AgNPs surface to 4-NP. It exhibits the great potential of 2D silica nanosheets as support materials for the efficient assembly of uniform noble-metal nanoparticles. Moreover, the 2D AgNPs/SiNSs nanocomposite holds a stable catalytic efficiency (around 100%) over five reaction cycles. The high efficiency and convenience have been demonstrated by purifying the 4-NP polluted water in the "filtering and catalyzing" device, in which the polluted water could become colorless within 10 s. [ABSTRACT FROM AUTHOR]

Modified kaolinite nanolayers were prepared from two-dimensional (2D) raw kaolin through a combination of calcination, acid leaching, and ultrasonic dispersion. The obtained nanolayers were subjected to effective modification with amino functional groups through grafting with (3-aminopropyl) triethoxysilane (APTES). The resultant materials were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS), scanning transmission electron microscopy (STEM), Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The results revealed that the chemically modified materials exhibited increased specific surface area and pore structures, and chemical treatments showed obvious effects on the adsorption performance of kaolin. Owing to the protonation of the amino groups, the organic modified material exhibited excellent adsorption performance for Congo red and efficient regeneration. The chemically modified kaolinite nanolayers show significant potential applications in the fields of adsorption, separation, catalysis, and other environmental remediation. [ABSTRACT FROM AUTHOR]

Latent heat thermal energy storage (LHTES) system that centers on organic phase change materials (PCM) is regarded as an efficient strategy for the utilization of solar energy. The leakage problem and insensitivity to the sunlight of organic PCM significantly limit the large-scale application in the solar energy storage field. In the current study, a composite shape-stabilized phase change material (ss-PCM) for solar energy utilization was fabricated by incorporating stearic acid (SA) into the carbon-coated aluminosilicate nanolayers developed through intercalation of kaolinite with potassium acetate and then calcination. The resulting composite ss-PCM without leakage possesses excellent encapsulation ability (63.8%) and high latent enthalpy (132.0 J/g), which are ascribed to the higher specific surface area and pore volume of the carbon-coated aluminosilicate nanolayers, and good compatibility. The photo-thermal conversion efficiency of the final composite ss-PCM is up to 92.1%. After 500 heating-cooling cycles, the number of thermal cycles does not show an apparent effect on the enthalpy of the composite ss-PCM, implying its outstanding thermal cycle stability. The mechanism of leakage proof and photo-thermal conversion performance enhancement of composite ss-PCM were explored. The leakproof ability of composite ss-PCM is not only related to the solid capillary force and surface tension of carbon-coated aluminosilicate nanolayers but also the strong chemical bond between SA molecules and these nanolayers. The carbon layers of the supporting material provide an excellent light absorption property. Hence, this work may offer a new idea for designing and constructing the clay mineral (kaolinite) with a special nanolayer structure for preparing composite ss-PCM with superior photo-thermal conversion and solar energy storage capacity. [Display omitted] • A facile route was introduced to synthesize carbon coated aluminosilicate nanosheets (KK600). • The final composite ss-PCM with high enthalpy and long-term cyclic stability was achieved. • The interaction between SA and KK600 was revealed by in-situ FTIR. • The photo-thermal conversion efficiency of the final composite ss-PCM is up to 92.1%. [ABSTRACT FROM AUTHOR]

Three kinds of kaolinites (platelet, PKaol; layered, LKaol; and rod, RKaol) were used to stabilize paraffin to prepare PKaol/paraffin, LKaol/paraffin, and RKaol/paraffin composites. The effects of kaolinite microstructure on the thermal storage properties of the composites were investigated in detail. It was found that the crystallinity of the paraffin in the composites increased when the proportion of kaolinite pores that are smaller than 5 nm decreased; the pore size also affected the transfer of the heat within the paraffin in the region near the kaolinite. The paraffin in LKaol/paraffin composite showed higher crystallinity ( F c , 98.4%) and greater effective energy storage per unit mass ( E ef , 215.6 J·g − 1 ) than that in the two other composites, indicating that most of the paraffin can contribute to energy storage. This is probably because the LKaol pore structure is more suitable for supporting phase change materials (PCM). This also led to less phonon scattering and therefore a larger phonon mean free path for paraffin in this composite, and a higher thermal conductivity (0.78 W·m − 1 ·K − 1 ). Furthermore, the effect of nanopore confinement within the composites was elucidated at the atomic level. The as-prepared PCM have potential for application in solar thermal energy storage and solar heating. [ABSTRACT FROM AUTHOR]

Highlights: [•] Spherical CdS nanoparticles were uniformly assembled onto kaolinite rods. [•] CdS/kaolinite nanocomposites showed better luminescence properties than pure CdS. [•] Hydrogen bonds could be formed between kaolinite and polyvinylpyrrolidone. [•] Atomic-level interaction between CdS particles and kaolinite surfaces was depicted. [Copyright &y& Elsevier]

Ulcerative colitis (UC) affects millions of people worldwide and is currently incurable. As such, there is an urgent need for effective drugs that will promote UC remission. This study investigated the therapeutic effects of five typical natural minerals on UC induced by dextran sulfate sodium (DSS): kaolinite (Kaol), halloysite (Hal), diatomite (Dia), montmorillonite (Mt), and palygorskite (Pal). These minerals were characterized by lamellar, tubular, columnar porous, and fibrous morphologies, as well as centered size distribution and negative charge. In vivo experiments indicated that natural minerals had a remission effect on UC and altered gut flora, especially Kaol. These results suggest that natural minerals can serve as drugs, or drug carriers, to attain synergistic effects with other drugs for UC therapy. Unlabelled Image • Five natural minerals for ulcerative colitis (UC) therapy were in vivo evaluated. • Natural minerals exhibited different therapeutic efficiency on ulcerative colitis. • Microflora in UC mice colon could be altered toward balance by clay minerals. [ABSTRACT FROM AUTHOR]

To explore the effect of particle size distributions of supports on thermal performances of phase change materials (PCMs), shape-stabilized composites were prepared by using stearic acid (SA) to hybridize size-different kaolinite (Kaol). The samples were characterized using SEM, XRD, FTIR, BET and DSC techniques. The results indicated that superior thermal capacity was ascribed to higher loading capacity and crystallinity of SA, which was closely related to the layout state of Kaol within the composites. Enhanced thermal conductivity could be achieved with the increasing crystallinity, the descending interfacial thermal resistance and efficient heat conductive network. The establishment of heat transfer network depended largely on the mutual proportion between small-sized and large-sized particles in supports. The tiny particles were inferred to act as junctions to bridge the separately dispersed plates, which was contributed to the continuous heat conducting pathways. The results suggested that particle size distributions of Kaol could exert a great influence on thermal performances of composites. Furthermore, Kaol could obviously uplift the thermal stability of composites, and the thermal cycling test has validated its excellent thermal reliability. We believe that this study will play an enlightening role in the design and fabrication of highly-efficient shape-stabilized PCMs for solar energy storage. Unlabelled Image • Kaolinite-based stearic acid composite was prepared via vacuum-assisted method. • Effect of kaolinite size distribution on thermal performance was studied. • Uniformization of kaolinite size helped to improve thermal enthalpy. • Construction of heat conductive network depended on particle size distribution. [ABSTRACT FROM AUTHOR]

Uncontrolled bleeding following trauma is associated with a high risk of death. The two-dimensional (2D) nanoclay kaolinite as an effective hemostatic has been developed for early intervention to prevent blood loss. However, the interfacial interactions between kaolinite and blood cells in hemostasis, and the effects of the stacking structure or particle size of kaolinite on bleeding control are unclear. Here, the interactions between kaolinite and blood cells were analyzed qualitatively and quantitatively by using scanning electron microscopy, confocal laser-scanning microscopy, and flow cytometry. The results showed that kaolinite not only bonds with platelets but also induces platelets aggregation, and does not disturb red blood cells, which facilitates the formation of blood clotting in hemostasis. Further, kaolinite nanoclay with smaller nanosheets and looser aggregation showed higher hemostatic activity, which was attributed to the higher water absorption capacity, and the ability to activate the intrinsic coagulation pathway and platelets activation and aggregation. Accordingly, controlling the particle size or thickness and aggregate status of kaolinite or 2D nanoclay nanosheets could be an alternative strategy for enhancing the hemostatic activity of 2D nanoclay-based materials. Unlabelled Image • Interactions between kaolinite nanoclay and blood cells in hemostasis are analyzed. • Kaolinite could bond with platelets and induce platelets aggregation. • Interfacial interactions facilitate the formation of blood clotting in hemostasis. • Kaolinite nanoclay with smaller nanosheets showed higher hemostatic activity. [ABSTRACT FROM AUTHOR]