Layered Double Hydroxide Nanocomposites Research Articles

Cellulose-based Co[sbnd]Fe LDH composite as a nano-adsorbent for sulfamethoxazole and cefixime residues: Evaluation of performance, green metrics and cytotoxicity

The increase in antibiotic residues poses a serious threat to ecological and aquatic environments, necessitating the development of cost-effective, convenient, and recyclable adsorbents. In our study, we used cellulose-based layered double hydroxide (LDH) as an efficient adsorbent and nanocarrier for both sulfamethoxazole (SMX) and cefixime (CFX) residues due to their biodegradability and biocompatibility. Chemical processes are measured according to green chemistry metrics to identify which features adhere to the principles. A GREEnness Assessment (ESA), Analytical GREEnness Preparation (AGREEprep), and Analytical Eco-Scale Assessments (ESA) were used to assess the suitability of the proposed analytical method. We extensively analyzed the synthesized CoFe LDH/cellulose before and after the adsorption processes using XRD, FTIR, and SEM. We investigated the factors affecting the adsorption process, such as pH, adsorbent dose, concentrations of SMX and CFX and time. We studied six nonlinear adsorption isotherm models at pH 5 using CoFe LDH, which showed maximum adsorption capacities (qmax) of 272.13 mg/g for SMX and 208.00 mg/g for CFX. Kinetic studies were also conducted. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was performed on Vero cells in direct contact with LDH nanocomposites to evaluate the cytotoxicity and side effects of cellulose-based CoFe LDH. The cellulose-based CoFe LDH nanocomposite demonstrated excellent cytocompatibility and less cytotoxic effects on the tested cell line. These results validate the potential use of these unique LDH-based cellulose cytocompatible biomaterials for water treatment applications. The cost of the prepared adsorbents was investigated.

Tailored thymoquinone intercalated Layered Double Hydroxide (LDH) nanocomposites to accelerate mineralization for enhanced osteogenesis

The tunable nature of two-dimensional nanostructured Layered Double Hydroxides [LDH] and their effective intercalation ability with biomolecules make them inevitable functional hybrid materials for versatile biomedical applications. In an attempt to meet the limitations in existing bone reconstruction practice, the present work reports the synthesis of zinc and iron-based LDH [Zn-Fe LDH] and its subsequent intercalation with thymoquinone [TQ-Zn-Fe LDH] to augment osteoblastic differentiation and proliferation for accelerated bone mineralization. Structural studies depicted the polycrystalline and amorphous nature of ZnFe LDH and TQ-Zn-Fe LDH respectively. The biocompatible nature of LDHs was proven by negative cytotoxicity, cell adhesion, and proliferation assays studied in MG-63 cell lines. Gene expression studies of the nanocomposites showed a fold change of 5–10 in osteoblastic differentiation and proliferation. However, TQ-Zn-Fe LDH treated cells showed significantly higher protein translation levels of osteogenesis markers and elevated alkaline phosphatase secretion and calcium deposition on day 21, confirming their osteogenic efficiency. Thus, acquired results speculate the osteogenic potential of thymoquinone intercalated TQ-Zn-Fe-LDH to meet the limitations in bone reconstruction practice.

Carbon supported ternary layered double hydroxide nanocomposite for Fluoxetine removal and subsequent utilization of spent adsorbent as antidepressant

Fluoxetine (FLX) is one of the most persistent pharmaceuticals found in wastewater due to increased use of antidepressant drugs in recent decades. In this study, a nanocomposite of ternary ZnCoAl layered double hydroxide supported on activated carbon (LAC) was used as an adsorbent for FLX in wastewater effluents. The nanocomposite was characterized using Fourier Transform Infrared Spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), and surface area analysis (BET). The adsorption investigations showed that the maximum removal capacity was achieved at pH 10, with a 0.1 g/L adsorbent dose, 50 mL volume of solution, and at a temperature of 25 °C. The FLX adsorption process followed the Langmuir–Freundlich model with a maximum adsorption capacity of 450.92 mg/g at FLX concentration of 50 µg/mL. Density functional theory (DFT) computations were used to study the adsorption mechanism of FLX and its protonated species. The safety and toxicity of the nanocomposite formed from the adsorption of FLX onto LAC (FLX-LAC) was investigated in male albino rats. Acute toxicity was evaluated using probit analysis after 2, 6, and 24 h to determine LD50 and LD100 values in a rat model. The FLX-LAC (20 mg/kg) significantly increased and lengthened the sleep time of the rats, which is important, especially with commonly used antidepressants, compared to the pure standard FLX (7 mg/kg), regular thiopental sodium medicine (30 mg/kg), and LAC alone (9 mg/kg). This study demonstrated the safety and longer sleeping duration in insomniac patients after single-dose therapy with FLX-LAC. Selective serotonin reuptake inhibitors (SSRIs) like FLX were found to have decreased side effects and were considered the first-line mood disorder therapies.

Elongational flow‐induced microstructure evolutions in polypropylene/layered double hydroxides nanocomposites

AbstractIn this work, the effect of the non‐isothermal elongational flow on the morphology and mechanical properties of polypropylene (PP)‐based nanocomposites containing Mg‐Al layered double hydroxides (LDHs) modified with stearate or oleate functional groups has been investigated. In particular, nanocomposites containing 5 and 10 wt% of LDHs prepared through melt compounding were subjected to uniaxial elongational flow at the exit of the extruder, leading to the formation of fibers characterized by different draw ratios (DRs). The mechanical characterization of the fibers demonstrated a progressive enhancement of the tensile strength as a function of the DR with increasing the content of nanofillers. Notably, for the fibers stretched at a DR of 200 and containing 10 wt% of LDHs modified with oleate groups, the tensile strength increased fourfold as compared to that of the unfilled matrix. These results have been attributed to a progressive enhancement of the extent of the dispersions of the embedded LDHs induced by the application of the elongational flow, as also confirmed by morphological analyses. In all, the obtained results demonstrated the beneficial effect of the elongational flow in promoting the achievement of superior mechanical properties in LDHs‐containing nanocomposites, hence widening the application field of these nanostructured materials.Highlights PP/organomodified LDH nanocomposites were obtained through melt compounding. Nonisothermal elongational flow was applied to the extrudates at the die exit. Anisotropic fibers showed progressively enhanced tensile strength values. Elongational flow promoted a gradual evolution of the material microstructure. A gradual improvement of the nanofiller dispersion was observed upon elongation.

Development of polysaccharide-coated layered double hydroxide nanocomposites for enhanced oral insulin delivery.

Oral insulin (INS) is predicted to have the most therapeutic advantages in treating diabetes to repress hepatic glucose production through its potential to mimic the endogenous insulin pathway. Many oral insulin delivery systems have been investigated. Layered double hydroxide (LDH) as an inorganic material has been widely used in drug delivery thanks to its appealing features such as good biocompatibility, low toxicity, and excellent loading capability. However, when used in oral drug delivery, the effectiveness of LDH is limited due to the acidic degradation in the stomach. In this study, to overcome these challenges, chitosan (Chi) and alginate (Alg) dual-coated LDH nanocomposites with the loading of insulin (Alg-Chi-LDH@INS) were developed by the layered-by-layered method for oral insulin delivery with dynamic size of ~ 350.8nm, negative charge of ~ - 13.0mV, and dispersity index 0.228. The insulin release profile was evaluated by ultraviolet-visible spectroscopy. The drug release profiles evidenced that alginate and chitosan coating partially protect insulin release from a burst release in acidic conditions. The analysis using flow cytometry showed that chitosan coating significantly enhanced the uptake of LDH@INS by Caco-2 cells compared to unmodified LDH and free insulin. Further in the in vivo study in streptozocin-induced diabetic mice, a significant hypoglycemic effect was maintained following oral administration with great biocompatibility (~ 50% blood glucose level reduction at 4h). This research has thus provided a potential nanocomposite system for oral delivery of insulin.

Fabrication of the CNTs/NiAl–LDH nanocomposite as a carrier of a luminescent sensor for DNA detection

Since the 21st century, nanocomposites based on layered double hydroxide (LDH) and carbon nanotubes (CNTs) are extensively employed as heat stabilizers, supercapacitors and electrocatalysts, due to their high conductivity, outstanding stability and environmental friendliness. Herein, CNTs/NiAl–LDH composite were obtained by one-step hydrothermal method and used as a platform for Ru(phen)3Cl2 (tris(1,10-phenanthroline)ruthenium (II) dichloride) sensor to selectively detect CT DNA (Calf thymus DNA). It was found that CNTs/NiAl–LDH composite could effectively quench the emission of the Ru(phen)3Cl2 sensor in aqueous solution. After adding a certain amount of CT DNA to the above system, the Ru(phen)3Cl2 interacted with CT DNA immediately and released from the CNTs/NiAl–LDH, resulting in the fluorescence recovery. In the concentration range of 4.4–26.3 μg/mL, the increase of luminescence was linearly proportional to the amount of CT DNA added, and the correlation coefficient was 0.9967. The detection limit was 6.09 × 10−8 g/mL.

Exfoliated Poly (styrene-co-urethane) Grafted - Polymethylmethacrylate /Layered Double Hydroxide Nanocomposite Synthesized by Metal Catalyzed Living Radical Polymerization and Solvent Blending Method

Exfoliated Poly (styrene-co-urethane) Grafted - Polymethylmethacrylate /Layered Double Hydroxide Nanocomposite Synthesized by Metal Catalyzed Living Radical Polymerization and Solvent Blending Method

Purpurin intercalated layered double hydroxide nanocomposites for improved CO2 visible photocatalytic reduction: Dye-intercalation stabilization and sensitization

Purpurin(pp) can be used as a photosensitive molecule in photocatalytic systems due to its excellent absorption of visible light, but its application is limited due to its poor stability under light. Layered double hydroxides (LDHs) can act as molecular containers due to their interlayer anion exchangeability, introducing target anions into the interlayer of LDHs and improving the instability of anions by utilizing the 2D confinement environment between LDHs layers. A series of co-intercalation materials with different ratios of pp and dodecyl sulfonate (SDS) were prepared through the hydrothermal method in this work, denoted as SDS-pp(x%)/LDHs. Compared with pp, the absorbance retention rate of SDS-pp(x%)/LDHs increased from 12.5% to 90% after 5 h of light exposure. Then its potential application in visible photocatalytic reduction of CO2 was explored. When the intercalation ratio of pp is 3%, the performance is optimal. Compared with ZnAl LDHs, the yield of CO produced by SDS-pp(3%)/LDHs was increased by 12 times and a small amount of 8-electron reduction product CH4 appeared. Through mechanism exploration, the matching energy level relationship between pp and LDHs promotes electron transfer from pp to LDHs. In addition, the catalyst exhibits good cyclic photocatalytic reduction performance for CO2 due to its stable intercalation structure.

Carbonaceous CoCr LDH nanocomposite as a light-responsive sonocatalyst for treatment of a plasticizer-containing water

The carbonous-based nanocomposites of CoCr layered double hydroxide (LDH) with graphene oxide (GO) and reduced graphene oxide (rGO) were prepared. The successful synthesis of the CoCr LDH in hydrotalcite crystalline structure was deduced from the pattern obtained from X-ray diffraction, and the chemical composition of its surface was checked by X-ray photoelectron spectroscopy. The prosperous decorating of LDH on the sheets of rGO and GO was authenticated by the energy dispersive X-ray spectroscopy analysis and micrographs of scanning electron and transmission electron microscopy. The photo-assisted sonocatalytic activity of the prepared nanocomposites was appraised for the decomposition of dimethyl phthalate (DMP) as a plasticizer. The highest decomposition efficiency of 100% was obtained in the existence of CoCr LDH/rGO nanocomposite (0.5 g/L) during 20 min of reaction time via photo-assisted sonocatalysis. The rGO improved the catalytic activity of the CoCr LDH by increasing the specific surface area from 1.2 m2/g to 4.5 m2/g and reducing the band gap from 1.7 eV to 1.3 eV. Moreover, the results of the colony-forming unit method endorsed antibacterial property improvement of the CoCr LDH via hybridizing with rGO. The results of this research provide an optimistic perspective for applying carbonous-based nanocomposites of CoCr LDH as a novel catalyst with antibacterial properties in photo-assisted sonocatalytic processes.

Antimicrobial properties of promising Zn–Fe based layered double hydroxides for the disinfection of real dairy wastewater effluents

Bacterial resistance to conventional antibiotics is a serious challenge that requires novel antibacterial agents. Moreover, wastewater from dairy farms might contain countless number of pathogens, organic contaminants and heavy metals that consider a threat to the terrestrial and aquatic environment. Therefore, the development of cost-effective, highly operation-convenient, recyclable multifunctional antimicrobial agents became an urgent necessity. Layered double hydroxides (LDH) have shown promising results as antibacterial agents. However, more work is required to further investigate and improve the antimicrobial performance of LDH structures against pathogens. In this study three Zn–Fe based LDH were investigated for real dairy wastewater disinfection. The three LDH samples were cobalt substituted Zn–Fe LDH (CoZnFe), magnesium substituted Zn–Fe LDH (MgZnFe) and MgZnFe-Triazol LDH (MgZnFe-Tz) nanocomposite. Seventy-five wastewater samples were collected from a dairy farm sewage system. The sensitivity of isolated pathogens was tested against two commonly used disinfectants (Terminator and TH4) and was assessed against the three LDH samples at different concentrations. The overall prevalence of S. agalactiae, S. dysgalactiae and Staph. aureus was significantly at 80.0% (P-value = 0.008, X2 = 9.700). There was variable degree of resistance to the tested disinfectants, whereas the antimicrobial activity of CoZnFe LDH was increased significantly at a concentration of 0.005 mg/L followed by MgZnFe LDH while MgZnFe-Tz LDH showed minor antibacterial potency. It was concluded that CoZnFe LDH showed a better biocidal activity in killing the isolated resistant pathogens, making it a good choice tool in combating the zoonotic microbes in wastewater sources.

Ti3SiC2-coupled NiCoMn LDH nanocomposites as positive electrode for high performance supercapacitors

The layered structure of layered double hydroxides (LDH) is essential for its usage as an electrode material, yet the absence of efficient charge exchange across layered structures severely limits LDH’s employment in supercapacitors. In this work, NiCoMn LDH (abbreviated as LDH) and its composite with Ti3SiC2 MAXenes in 3 %, 6 % and 12 % by weight (abbreviated as LDH/M3, LDH/M6 and LDH/M12, respectively) were synthesized using the probe sonication method. The LDH/M6 electrode had a higher maximum specific capacitance (566.6 F/g) than the LDH (480.83 F/g), LDH/M3 (508 F/g), and LDH/M12 (489.1 F/g) electrodes at a current density of 0.5 A/g, which is about 16 %, 11 %, and 14 % higher than the aforementioned electrodes, respectively, demonstrating the effectiveness of using Ti3SiC2 MAXenes nanosheets. At 0.5 A/g, the capacitance of the asymmetric supercapacitor’s ideal LDH/M6 electrode is 162.2 F/g, and the energy and power densities are 72.8 Wh/kg and 450 W/kg, respectively. Its stability results showed an impressive 93 % capacity retention after 4000 cycles. Further, its overall hybrid-type performance was confirmed by analyzing its diffusive-capacitive behavior, which demonstrated 32 % capacitive and 68 % diffusive behavior. This promising performance indicates that LDH/M6 can be used as electrode material in high-performance supercapacitors.

Nickel Cobalt LDH/Graphene Film on Nickel-Foam-Supported Ternary Transition Metal Oxides for Supercapacitor Applications

Layered double hydroxides (LDHs) of transition metals have attained significant attention for supercapacitor applications due to their excellent charge storage, low internal resistance, and superior electrochemical stability. Here, a nanocomposite of reduced graphene oxide/nickel cobalt layered double hydroxide (rGO/NiCo LDH) on the surface of nickel foam (NF) containing hierarchical nickel cobalt copper transition metal oxides (TMOs) is prepared through two-step processes of electrochemical and coprecipitation methods. The TMOs/rGO/NiCo LDH nanocomposite is characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR), Raman, X-ray energy-dispersive (EDS), and X-ray photoelectron (XPS) spectroscopies as well as by transmission electron microscopy (TEM), field-emission scanning electron microscopy (FE-SEM), elemental mapping analysis, nitrogen adsorption/desorption, and contact angle measurements. The supercapacitive behavior of the electrodes has been investigated through cyclic voltammetry (CV), galvanostatic charge–discharge (GCD) measurements, and electrochemical impedance spectroscopy (EIS). The study has shown that the synergetic effect and the electrochemical properties have considerably improved when the layered double hydroxides are synthesized in the presence of rGO. The TMOs/rGO/NiCo LDH nanocomposite exhibits an excellent specific capacitance of 2763 F g–1 at a current density of 1 A g–1 and a stability of 85% after 3000 GCD cycles at a current density of 24 A g–1. Also, a TMOs/rGO/NiCo LDH//rGO asymmetric supercapacitor device is constructed with an aqueous KOH electrolyte, which shows a capacitance of 244 F g–1 at a current density of 1 A g–1. The device attains the highest energy density of 34 Wh kg–1 and power density of 2500 W kg–1, with an excellent cycling stability of 100% after 3000 GCD cycles at a current density of 10 A g–1.

Biomaterials Based on Organic Polymers and Layered Double Hydroxides Nanocomposites: Drug Delivery and Tissue Engineering.

The development of biomaterials has a substantial role in pharmaceutical and medical strategies for the enhancement of life quality. This review work focused on versatile biomaterials based on nanocomposites comprising organic polymers and a class of layered inorganic nanoparticles, aiming for drug delivery (oral, transdermal, and ocular delivery) and tissue engineering (skin and bone therapies). Layered double hydroxides (LDHs) are 2D nanomaterials that can intercalate anionic bioactive species between the layers. The layers can hold metal cations that confer intrinsic biological activity to LDHs as well as biocompatibility. The intercalation of bioactive species between the layers allows the formation of drug delivery systems with elevated loading capacity and modified release profiles promoted by ion exchange and/or solubilization. The capacity of tissue integration, antigenicity, and stimulation of collagen formation, among other beneficial characteristics of LDH, have been observed by in vivo assays. The association between the properties of biocompatible polymers and LDH-drug nanohybrids produces multifunctional nanocomposites compatible with living matter. Such nanocomposites are stimuli-responsive, show appropriate mechanical properties, and can be prepared by creative methods that allow a fine-tuning of drug release. They are processed in the end form of films, beads, gels, monoliths etc., to reach orientated therapeutic applications. Several studies attest to the higher performance of polymer/LDH-drug nanocomposite compared to the LDH-drug hybrid or the free drug.

Ultrasound-assisted photocatalytic decomposition of rifadin with biochar and CNT-based NiCr layered double hydroxides

Modification of layered double hydroxides (LDHs) is known to be beneficial for boosting the consistent formation of reactive oxygen species (ROSs) and enhancing the photocatalytic process. Herein, a facile synthesis method for preparing carbon nanotube (CNT) and biochar (BC)-based NiCr LDH (NC) nanocomposites as a sonophotocatalyst for the efficient degradation of rifadin (RA) was provided. The formation of thin nanosheet structures of NC along with porous and nanotube structures of BC and CNT was well approved by scanning electron microscope (SEM) and high-resolution transmission electron microscope (HRTEM). The bandgaps of the nanocomposites and pristine LDH are determined by differential reflectance spectroscopy (DRS) analysis. Results unveiled that sonophotocatalysis presented high efficacy in comparison with sonocatalysis and photocatalysis. Under optimized conditions, a 15 mg L−1 of RA at pH 8 treated with 1 g L−1 of NiCr LDH/BC (NC/BC) demonstrated 80.3% sonophotocatalytic degradation during 90 min. To shed light on the durability and stability of NC/BC, four consecutive cycles were operated. The chemical structure and surface morphology of the reused catalyst were stable, revealed by SEM and Fourier transform infrared (FTIR) analyses. It is deduced that NC/BC is an advantageous sonophotocatalyst for the decomposition of emerging pharmaceuticals.

Sonocatalytic oxidative desulfurization of diesel oil using a novel BiVO4/FeMn LDH nanocomposite.

A novel BiVO4/FeMn layered double hydroxide (LDH) nanocomposite was fabricated and applied for green and efficient ultrasound-assisted oxidative desulfurization (UAODS) of real fuel (hydrotreated oil). The physicochemical properties of the prepared BiVO4/FeMn LDH nanocomposites are elucidated using techniques such as XRD, FT-IR, BET, SEM, XPS, Raman, and TGA. The desulfurization results revealed that both BiVO4 and FeMn LDH were crucial in the UAODS process in the presence of H2O2 as a green oxidant and acetonitrile as an extracting solvent. The desulfurization activity was optimized by varying the process conditions (time, catalyst weight, type of oxidant, O/S molar ratio, ratio of solvent to oil, and type of sonicator). The prepared nanocomposite exhibited remarkable desulfurization performance, reaching up to 99.8% under the optimized reaction conditions. Moreover, the catalyst exhibited high stability and could be reused four times without a notable decline in the performance. Significantly, this research reveals the robustness of the newly synthesized nanocomposite for efficient UAODS in a short time and low catalyst dosage. The proposed desulfurization mechanism was investigated.

Recent Developments in Titanium Carbide (Ti3C2)-Based Layered Double Hydroxide (LDH) Nanocomposites for Energy Storage and Conversion Applications: A Minireview and Perspectives

As a result of the rapid industrial development and increase of world population, energy and the environment have become the major issues that demand urgent attention. Introducing new materials with layered textures, low cost, and high surface areas could provide attractive strategies to overcome the challenges for sustainable development. In this perspective, titanium carbide (Ti3C2) MXenes and layered double hydroxides (LDHs) are extraordinary nanomaterials due their two-dimensional (2D) structures and excellent properties. Such materials offer the advantages of large surface area and excellent conducting properties. The Ti3C2 MXenes have outstanding 2D structure with outstanding electronic conductivity, whereas LDH has strong adsorption and semiconducting properties. Coupling them would be promising to form a good composite with higher efficiency. The main objectives of this work to investigate the recent development in Ti3C2-based LDH nanocomposites for energy storage and conversion applications. In this article firstly the synthesis techniques adopted for LDH, Ti3C2MXene and LDH/Ti3C2 MXeneare summarized whereas the optical and structural properties involved to obtain highly effecient materials are are also discussed. The advancements to obtain highly efficient hybridized material of LDH and TiC MXene for energy storage, hydrogen production, and carbon dioxide reduction have been systematically explained. Finally, the challenges and perspectives toward the future research of MXene-based LDH composites have been disclosed.

Trends in Layered Double Hydroxides‐Based Advanced Nanocomposites: Recent Progress and Latest Advancements

AbstractRecently, layered double hydroxides (LDHs) have gathered vast interest due to overall positive charge, unique crystallinity, and biocompatibility for diverse applications. Despite the advantageous attributes, these hydrotalcites often result in several limitations concerning the application requirements, such as aggregation, as well as poor chemical and thermal stabilities, hindering their scale‐up progress and practical utilization. In addressing these issues, the recent advancements in the fabrication of intelligent LDHs nanocomposites based on organically (polymer/polyelectrolyte)‐modified and inorganic (metal)‐composited architectures are systematically presented. Initially, a brief note on the shortcomings in various fields and the chemistry of these pristine LDHs is given. Then, various synthetic strategies used to fabricate these emerging LDH nanocomposites are comprehensively emphasized, focusing on the advancements in their structure and applicability. In addition, the effects of various attractive physicochemical attributes of LDHs and their nanocomposite forms are discussed, including their applicability in adsorption, biomedicine, catalysis, energy, and environment‐related applications. In summary, this article is concluded with an outlook concerning the positioning of LDH‐based nanocomposites compared to other innovative materials, as well as the current challenges and future requirements for scale‐up.

Improvement of optical, dielectric and mechanical properties of a new nanocomposite based on polyvinyl alcohol and layered double hydroxide

In this work, films in the form of poly (vinyl alcohol)/Layered Double Hydroxide (PVA/LDH) nanocomposites were synthesized with different amount of LDH (0%; 4% and 6%), and characterized by X-ray diffraction (XRD), infrared spectroscopy scanning electron microscopy (SEM), impedance spectroscopy and UV-Vis-NIR spectroscopy. Different characterizations were used to investigate the electrical/dielectric, optical and mechanical properties of the nanocomposite films XRD and infrared spectroscopy results showed that clay particles exist in the polymer matrix. Electrical modeling was established using an equivalent electrical circuit consisting of two blocks, and confirmed by fitting the experimental conductivity data according to Jonscher’s double power law. Moreover, the reinforcement of the composite matrix by the addition of LDH particles, showed a shift of the relaxations towards the low frequencies, and led to an increase of dielectric constant, conductivity, and absorption of the light in the ultraviolet domain with a decrease of the gap energy. As for the mechanical properties, namely the Young’s modulus, is tripled when the clay content is about 6%.

Ultrathin graphene@NiCo2S4@Ni-Mo layered double hydroxide with a 3D hierarchical flowers structure as a high performance positive electrode for hybrid supercapacitor

This study presents three-dimensional flower-like spheres composed of NiCo2S4@Ni-Mo layered double hydroxide (LDH) nanocomposites, which are grown in situ on reduced graphene oxide (RGO). The RGO@NiCo2S4@NiMo-LDH nanocomposites exhibit remarkable electrochemical properties and have a specific capacitance of 1346 F g−1 at the current density of 1 A g−1. In addition, using RGO@NiCo2S4 @NiMo-LDH hybrid nanosheets and activated carbon (AC) as the positive and negative electrodes, the asymmetric supercapacitor device was successfully assembled, and it showed a significant energy density of 59.38 Wh kg−1 at a power density of 808.19 W kg−1, with good cycle stability. The initial capacity retention rate is 80 % after 10,000 cycles. These results demonstrate the great potential of the synthesized RGO@NiCo2S4@NiMo-LDH composite for the development of high-performance electrode materials for supercapacitors.

Layered Double Hydroxides-Loaded Sorafenib Inhibit Hepatic Stellate Cells Proliferation and Activation In Vitro and Reduce Fibrosis In Vivo.

A core feature of liver fibrosis is the activation of hepatic stellate cells (HSCs), which are transformed into myofibroblasts and lead to the accumulation of extracellular matrix (ECM) proteins. In this study, we combined in vitro cellular efficacy with in vivo antifibrosis performance to evaluate the outcome of sorafenib (SRF) loaded layered double hydroxide (LDH) nanocomposite (LDH-SRF) on HSCs. The cellular uptake test has revealed that sorafenib encapsulated LDH nanoparticles were efficiently internalized by the HSC-T6 cells, synergistically inducing apoptosis of hepatic stellate cells. Moreover, the apoptosis rate and the migration inhibition rate induced by LDHs-SRF were 2.5 and 1.7 times that of SRF. Western Blot showed that the TGF-β1/Smad/EMT and AKT signaling pathway was significantly inhibited in HSC-T6 cells treated with LDHs-SRF. For the in vivo experiment, LDHs-SRF were administered to rat models of CCl4-induced liver fibrosis. H&E, masson and sirius red staining showed that LDHs-SRF could significantly reduce inflammatory infiltrate and collagen fiber deposition and immunohistochemical results found that LDHs-SRF treatment significantly inhibited the protein expressions of α-SMA in the liver, these results suggesting that LDHs-SRF exhibited better anti-fibrotic effect than SRF alone and significantly inhibited the proliferation and activation of rat hepatic stellate cells and collagen fiber synthesis.