Layered Double Hydroxide Nanoparticles Research Articles

Multiple phase transformation of ZIF-L to LDH and Ag nanoparticles decorated on CoNi layered double hydroxides for high-performance supercapacitor and highly efficient hydrogen evolution reaction

ZIF-L-derived binary layered double hydroxide (LDH) established active catalysts have been shown to have potential as electrode materials in the development of high-performance supercapacitors (SCs) and hydrogen evaluation reactions (HER). This study uses conductive nano-silver (Ag) particles in hierarchically integrated CoNi-LDH nanosheets (NSs), which are described. The developed Ag@CoNi-LDH NSs electrode has a very high specific capacitance of 2878 F g−1 at 0.5 A g−1 and an impressive rate capability. This is due to consistent morphology, plentiful electroactive sites, homogeneous particle size, and decreased electronic/ionic impedance. The fabrication of solid-state hybrid supercapacitors (HSCs) using Ag@CoNi-LDH NSs as the positive electrode and activated carbon (AC) as the negative electrode in PVA/KOH polymer gel electrolytes has been described. The prepared supercapacitors achieve a maximum energy density of 105 Wh kg−1 at power densities of 1183 Wh kg−1, coupled with excellent initial capacitance retentions of 97 % after 20,000 cycles. Ag@CoNi-LDH NSs demonstrate effective electrocatalytic activity towards HER with an ultra-low overpotential of 26 mV at 10 mA cm−2 and the associated Tafel value of 35 mV dec−1 using 0.5 M acidic electrolyte. It is possible to attribute the extraordinary electrochemical performance to the thoughtful mixture of two electroactive materials in the future.

Mg–Fe Layered Double Hydroxides/Polyacrylonitrile Nanofibers for Solar-Light Induced Peroxymonosulfate Elimination of Tetracycline Hydrochloride

The photo-induced peroxymonosulfate (photo-PMS) reaction is a promising route to eliminate antibiotics from waste water. To achieve excellent photo-PMS activity in Mg–Fe layered double hydroxides (LDHs) for tetracycline hydrochloride (TCH) degradation under simulative solar-light irradiation, Mg–Fe LDHs-loaded polyacrylonitrile (Mg–Fe/PAN) nanofibers were in-situ prepared via the hydrothermal route. For comparison to the photocatalysis and photo-PMS process, the Mg–Fe/PAN-assisted photo-PMS process exhibited a better elimination activity for TCH elimination. In addition, the photo-PMS activities of Mg–Fe/PAN composites were greatly affected by Mg–Fe LDHs content, TCH concentration, pH, and inorganic salts. Among these Mg–Fe/PAN composites, the optimal MgFe2/PAN with a Mg/Fe molar ratio of 1:2 and a nominal Mg–Fe LDHs content of 2.0 wt. % removed 81.31% TCH solution of 80 mg L−1 TCH within 120 min. This enhanced photo-PMS capacity of MgFe2/PAN was ascribed to the abundant active sites formed by functional groups and oxygen defects for efficient TCH species adsorption and photon capturing, and the tight interface between Mg–Fe LDHs nanoparticles and PAN nanofibers for the rapid separation and transfer of photoinduced e−/h+ pairs. SO4•− and •O2− radicals were vital for the MgFe2/PAN-assisted photo-PMS reaction.

Size-Optimized Layered Double Hydroxide Nanoparticles Promote Neural Progenitor Cells Differentiation of Embryonic Stem Cells Through the Regulation of M6A Methylation.

The committed differentiation fate regulation has been a difficult problem in the fields of stem cell research, evidence showed that nanomaterials could promote the differentiation of stem cells into specific cell types. Layered double hydroxide (LDH) nanoparticles possess the regulation function of stem cell fate, while the underlying mechanism needs to be investigated. In this study, the process of embryonic stem cells (ESCs) differentiate to neural progenitor cells (NPCs) by magnesium aluminum LDH (MgAl-LDH) was investigated. MgAl-LDH with diameters of 30, 50, and 100 nm were synthesized and characterized, and their effects on the cytotoxicity and differentiation of NPCs were detected in vitro. Dot blot and MeRIP-qPCR were performed to detect the level of m6A RNA methylation in nanoparticles-treated cells. Our work displayed that LDH nanoparticles of three different sizes were biocompatible with NPCs, and the addition of MgAl-LDH could significantly promote the process of ESCs differentiate to NPCs. 100 nm LDH has a stronger effect on promoting NPCs differentiation compared to 30 nm and 50 nm LDH. In addition, dot blot results indicated that the enhanced NPCs differentiation by MgAl-LDH was closely related to m6A RNA methylation process, and the major modification enzyme in LDH controlled NPCs differentiation may be the m6A RNA methyltransferase METTL3. The upregulated METTL3 by LDH increased the m6A level of Sox1 mRNA, enhancing its stability. This work reveals that MgAl-LDH nanoparticles can regulate the differentiation of ESCs into NPCs by increasing m6A RNA methylation modification of Sox1.

Orally ingestible medication utilizing layered double hydroxide nanoparticles strengthened alginate and hyaluronic acid-based hydrogel bead for bowel disease management

In the treatment of bowel diseases such as ulcerative colitis through oral administration, an effective drug delivery system targeting the colon is crucial for enhancing efficacy and minimizing side effects of therapeutic agents. This study focuses on the development of a novel nanocomposite hydrogel bead comprising a synergistic blend of biological macromolecules, namely sodium alginate (ALG) and hyaluronic acid (HA), reinforced with layered double hydroxide nanoparticles (LDHs) for the oral delivery of dual therapeutics. The synthesized hydrogel bead exhibits significantly enhanced gel strength and controllable release of methylprednisolone (MP) and curcumin (CUR), serving as an anti-inflammatory drug and a mucosal healing agent, compared to native ALG or ALG/HA hydrogel beads without LDHs. The physicochemical properties of the synthesized LDHs and hydrogel beads were characterized using various techniques, including scanning electron microscopy, zeta potential measurement, transmission electron microscopy, X-ray diffraction, and energy-dispersive X-ray spectroscopy. In vitro release studies of MP and CUR under simulated gastrointestinal tract (GIT) conditions demonstrate the superior controlled release property of the nanocomposite hydrogel bead, particularly in minimizing premature drug release in the upper GIT environment while sustaining release of over 82 % of drugs in the colonic environment. Thus, the modularly engineered carrier designed for oral colon targeting holds promise as a potential candidate for the treatment of ulcerative colitis.

NA-ALGINATE BEADS OF CALCIUM / IRON-LAYERED DOUBLE HYDROXIDE FOR TREATING WATER CONTAMINATED WITH AMOXICILLIN ANTIBIOTIC

The objective of this study was to prepare an adsorbent material from eggshells of chicken banished to the ambient as wastes to satisfy the ecological requirements of sustainable. The preparation process based on the extraction of calcium ions from eggshells and these ions must be reacted with iron to form nanoparticles of (Ca/Fe)-layered double hydroxides (LDHs) which immobilized as Na-alginate beads. Molar ration of calcium to iron, pH and dosage of LDH nanoparticles must be equal to 1, 12 and 5 g/100 mL to ensure that the prepared beads have highest ability to remove of Amoxicillin (AMOX) antibiotic with removal efficiency equal to 32% for operational conditions of Co=100 mg/L, beads dosage=0.5 g/50 mL, speed=200 rpm, pH=7 for 3 hrs. To increase this efficiency to ≥ 90%, best conditions must be time 90 min, pH 7, and beads mass 1.2 g/ 50 mL for Co 100 mg/L at 200 rpm in the batch mode. The Pseudo second order has high capability in the description of such tests with coefficient of determination (R2) ≥ 0.9924 and sum of squared error (SSE) ≤ 0.1287. Hence, the sorption of AMOX onto beads is governed by the chemisorption process. The reflections of XRD analysis proved the presence of (Ca/Fe)-LDH nanoparticles with size of 13.49 nm, calcium hydroxide (Ca(OH)2) and calcium carbonate (CaCO3)

Two‐Way Regulation of MgFe‐LDH on ESC Cell Fate via Temporal Selective Activation of Different Cell Membrane Receptors

AbstractStem cell fate regulation by biomaterials has considerable therapeutic potential; however, the mechanisms whereby biomaterials instruct stem cells for accurate fate regulation still need to be elucidated. Layered double hydroxide (LDH) nanoparticles are widely used for tissue regeneration because of their excellent physicochemical properties and biocompatibility. This study reveals that MgFe‐LDH has bidirectional regulatory effects on the differentiation of mouse embryonic stem cells into neural progenitor cells, essentially suppressing cell differentiation on the 1st day and promoting cell differentiation on the 3rd day. Single‐cell transcriptome sequencing and simulated computation of structural analysis demonstrate that MgFe‐LDH interacts with the membrane receptors leukemia inhibitory factor receptor (LIFR, 15 nm above the cell membrane) and pached1 (PTCH1, 6 nm above the cell membrane) on the 1st and 3rd day of differentiation, respectively. LIFR has more contact with MgFe‐LDH than PTCH1 and relatively weaker electrostatic interaction energies (−11010.0 and −9829.3 kJ mol−1 for PTCH1 and LIFR, respectively). These factors determine receptor binding and activation priority, followed by cell fate regulation. The results indicate that MgFe‐LDH regulate the activity and fate of stem cells dually, thus creating possibilities for personalized therapy in neurodevelopment and regenerative medicine through an in‐depth study of cell membrane receptors.

Intranasal delivery of phenytoin loaded layered double hydroxide nanoparticles improves therapeutic effect on epileptic seizures

Improving the efficiency of antiseizure medication entering the brain is the key to reducing its peripheral toxicity. A combination of intranasal administration and nanomedicine presents a practical approach for treating epileptic seizures via bypassing the blood-brain barrier. In this study, phenytoin (PHT) loaded layered double hydroxide nanoparticles (BSA-LDHs-PHT) were fabricated via a coprecipitation − hydrothermal method for epileptic seizure control. In this study, we expound on the preparation method and characterization of BSA-LDHs-PHT. In-vitro drug release experiment shows both rapid and continuous drug release from BSA-LDHs-PHT, which is crucial for acute seizure control and chronic epilepsy therapy. In-vivo biodistribution assays after intranasal administration indicate excellent brain targeting ability of BSA-LDHs. Compared to BSA-Cyanine5.5, BSA-LDHs-Cyanine5.5 were associated with a higher brain/peripheral ratio across all tested time points. Following intranasal delivery with small doses of BSA-LDHs-PHT, the latency of seizures in the pentylenetetrazole-induced mouse models was effectively improved. Collectively, the present study successfully designed and applied BSA-LDHs-PHT as a promising strategy for treating epileptic seizures with an enhanced therapeutic effect.

Fluorescence study of the interaction between albumin and layered double hydroxides

Layered double hydroxides nanoparticles (LDH-NP) are increasingly studied for biomedical applications. Nevertheless, their interaction with biomolecules such as proteins needs further exploration for an effective application. In this work, the adsorption of bovine serum albumin (BSA) on LDH-NP and the conformation changes of the protein upon adsorption were characterized using fluorescence spectroscopy. First, the quenching of tryptophan residues of BSA by chloride-intercalated LDH-NP was explored and the BSA adsorption capacity of LDH-NP were determined. Then, the structural conformation of the protein was analyzed by fluorescence spectroscopy (including synchronous, polarization and quenching studies) at different surface coverages. Finally, the proclivity of adsorbed BSA molecules to assemble as amyloid fibril was evaluated. Due to the positive charging and low curvature of LDH-NP, BSA molecules were strongly adsorbed, which produced a quenching of the protein fluorescence and a large adsorption capacity. The effect on BSA conformation was dependent on surface coverage (SC): at low values ,t he tryptophan residues were in more hydrophobic environments and more accessible to quenchers than al high ones. At low SC, there is space between the BSA molecules to spread on the surface, which led to a conformation change. Contrarily, the native conformation around tryptophan residues of BSA was preserved at high SC due to the tight packing of the adsorbed protein molecules. As a result, BSA molecules are stabilized against the formation of amyloid fibrils at high SC, while at low SC they present a similar fibrillation than free BSA.

Reduction of intracellular oxidative stress with a copper-incorporated layered double hydroxide.

Biocompatible Cu(II)-doped layered double hydroxide (CMA) nanoparticles were developed to combat reactive oxygen species. The 2-dimensional nanozymes showed both superoxide dismutase- and catalase-like activities in chemical assays, while proving as efficient antioxidants in the reduction of intracellular oxidative stress. The results indicate the great promise of CMA in antioxidant therapies.

Optimization Studies of Mg/Al-NO3 Layered Double Hydroxide Nanoparticles by Hydrothermal Treatment

Layered Double Hydroxides based nanoparticles offer significant advantages in biological applications with high biocompatibility and low cytotoxicity. In this study, nanoparticles (nMg/Al-NO3-LDH) were synthesized by the co-precipitation method and synthesis optimization of the nanoparticles was carried out by hydrothermal treatment. The effect of hydrothermal treatment on Z-average and surface charge was evaluated. Experiments were performed at 80˚C and 100˚C during in the range of 2-48 h by using different stirring rates (250, 1000, and 1500 rpm) and without stirring. Dynamic Light Scattering (DLS) was used to assess the particle size (nm), polydispersity index (PDI), and zeta potential (mV) of the nanoparticles. The chemical structure of nanoparticles was characterized by Fourier Transform Infrared spectrometry (FTIR). As a result, nanoparticles with an optimum particle size of 86.87 nm, a PDI of 0.132 and a zeta potential (mV) of 44.4±8.74 were obtained at 80˚C, 48h and 250 rpm. The data showed that Mg/Al-NO3-LDH nanoparticles have suitable physical properties for biological applications.

Layered double hydroxide nanoparticles for a smartphone digital image colorimetry-based determination of fluoride ions in water, milk and dental products

A novel smartphone digital image colorimetry-based approach was developed for fluoride ion determination, using layered double hydroxide (LDH) nanoparticles (Mg2Al(OH)7) as sorbents for analyte preconcentration and as a source of a central metal ion for a colored complex formation. A cotton rotating disk provided effective retention of the LDH nanoparticles during solid-phase microextraction and elution, excluding time-consuming centrifugation process. In the proposed procedure, the nanoparticles acted as aluminum ion source for alizarin complexone-Al3+-F– complex formation. An image of Eppendorf tube, containing the colored complex solution was obtained by a smartphone and converted, using the RGB model for fluoride ion determination. The procedure had a linear range of 0.20–20 mg L−1 with a limit of detection of 0.06 mg L−1. The developed procedure provided effective fluoride separation from various matrices for its determination by a smartphone without additional sample pretreatment.

Mixed matrix membrane based on PEBAX® filled with layered double hydroxides

The effect of incorporating layered double hydroxide (LDH) nanoparticles containing different molar ratios of metals on the thermal, mechanical, and gas permeation properties of membranes based on PEBAX® was evaluated. The three nanoparticles were synthesized using molar x-ratios (x = Al/(Mg + Al)) equal to 0.20, 0.25 and 0.33. The dispersed nanoparticles changed thermal resistance, improved mechanical properties and CO2/CH4 separation performance of MMM when compared to the membranes of neat PEBAX®. The addition of 2 % of LDH in PEBAX® 1657 promoted an increase of about 17 % in the elastic modulus and 10 % in the stress at break. The best result of permeation tests (1657–0.33–5 % MMM at 0.5 bar), shows increase CO2 permeability by 44 % and CO2/CH4 selectivity by 115 % as compared to the neat material. Gas permeation results showed that LDH with more anions favors the facilitated transport of CO2.

Vapor-Induced Assembly of a Platinum(II) Complex Loaded on Layered Double Hydroxide Nanoparticles.

Invited for the cover of this issue is the group of Masaki Yoshida and Masako Kato at Hokkaido University/Kwansei Gakuin University. The image depicts the changes in the assembly of PtII complexes with humidity on layered double hydroxide (LDH) nanoparticles, resulting in a drastic emission color change from green to orange. Read the full text of the article at 10.1002/chem.202301993.

Front Cover: Vapor‐Induced Assembly of a Platinum(II) Complex Loaded on Layered Double Hydroxide Nanoparticles (Chem. Eur. J. 60/2023)

Front Cover: Vapor‐Induced Assembly of a Platinum(II) Complex Loaded on Layered Double Hydroxide Nanoparticles (Chem. Eur. J. 60/2023)

Vapor-Induced Assembly of a Platinum(II) Complex Loaded on Layered Double Hydroxide Nanoparticles.

Controlled self-assembly of PtII complexes is key to the development of optical and stimuli-responsive materials, but designing and precisely controlling them is still difficult owing to weak intermolecular interactions. Herein, we report the successful water-vapor-induced assembly of an anionic PtII complex [Pt(CN)2 (ppy)]- (Hppy=2-phenylpyridine) electrostatically loaded onto cationically charged layered double hydroxide (LDH) nanoparticles consisting of Mg2+ and Al3+ ions. When the PtII complexes were densely loaded onto the LDH nanoparticles, the assembly was maintained, even in dilute aqueous media. In the case of sparse loading, the PtII complexes were loaded discretely in the dry state; however, when water vapor was adsorbed, the increased mobility of the PtII complexes led to their assembly on the LDH nanoparticles. The presence of water vapor led to a drastic change in luminescence from green to orange.

Synthesis of calcium-bismuth layered double hydroxide (LADH) nanoparticles: Applications as photo-catalyst and fuel additive

The development of calcium-bismuth layered double hydroxide [(Ca-Bi) LADH] microflowers for catalyzing degradation of Congo red (CR) and combustion of fuel is significant and highly desirable. Ca-Bi LADH microflowers are prepared by hydrothermal method with intercalated nitrates ions in inter lamellar spaces with 3–4 µm diameter and exposed active sites. After hydrothermal heating, the product is calcined at 400 °C for 4 and 7 hr to study the effect of calcination time on morphology of LADH. Prepared LADH is characterized by X-Ray diffraction and scanning electron microscopy (SEM). It is clear from XRD pattern that product is consist of hexagonal unit cell and highly crystalline. Synthesized LADH is used as catalyst for degradation of dye and combustion of fuel. The values of apparent rate constant (kapp) of catalytic degradation of CR are 0.0528, 0.0550, 0.0550 and 0.0557 min−1 for 1.0, 1.5, 2.0 and 2.5 mg/mL catalyst dosage respectively. Different parameters like flash point, fire point, kinematic viscosity and cloud point of fuel are increased by increasing additive dosage due to high surface area of LADH. LADH degrades dye in aqueous medium due to large number of adsorption sites. Synthesis of Ca-Bi LADH microflowers involves low cost and environmental friendly materials that can be used for different applications.

Intercalation of Ionic Liquids into LDH Structures for Microwave-Accelerated Polymerizations.

Microwave-accelerated ring-opening polymerization (ROP) of cyclic esters catalyzed by ionic liquid (IL) anions, intercalated into layered double hydroxides (LDHs), has been recently described as a fast and environmentally friendly synthetic way to prepare biodegradable polyester/LDH nanocomposites. However, to observe this synergistic catalytic effect between microwaves and IL anions and to achieve a homogeneous structure of the final polymer nanocomposite, the IL anions must be efficiently intercalated inside the LDH structure. Herein, we investigate the effects of various metal compositions of M2+/Al3+ LDHs (M = Mg, Co, and Ca) and different LDH synthetic routes (one-step direct coprecipitation, two-step coprecipitation/anion exchange, and two-step urea/anion exchange) on the intercalation efficiency of trihexyltetradecylphosphonium bis(2,4,4-trimethylpentyl)phosphinate IL. The most effective IL anion intercalation was observed for Ca2+/Al3+ LDH prepared using the two-step method consisting of coprecipitation and subsequent anion exchange. After optimization, this synthetic pathway led to the production of LDHs with intercalated IL anions and a reduced amount of intercalated water (<0.6 wt %). The catalytic ability of thus optimized LDH particles was demonstrated on the microwave-assisted ROP of ε-caprolactone, showing rapid progress of polymerization. Within minutes, the polycaprolactones with an average molecular mass in the range of 20 000-50 000 g/mol containing fully delaminated and exfoliated LDH nanoparticles were obtained.

Clay-based durable catalyst membranes of porous layered double hydroxide and gold nanoparticle nanocomposites for fast and continuous-flow reactions

We synthesized the hybrid catalyst of a porous layered double hydroxide (LDH) decorated with ultrasmall Au nanoparticles. The porous LDH was prepared by coprecipitation and ethanol washing, producing thin LDH nanoplatelets. Thereafter, spray drying was carried out, affording a few hundred nm of the hydrangea-like structure of the LDH with an extensive open network and a Brunauer–Emmett–Teller surface area of 386 m2/g. Its sizable open frame and active hydroxide surface enabled the uniform decoration of average 4-nm-diameter Au nanoparticles (Au/P-LDH) through one-pot chemical reduction using NaBH4 at room temperature. We applied the Au/P-LDH for the fabrication of catalyst membranes, which are potentially valuable for the continuous flow of catalytic reactions, e.g., the hydrogenation of p-nitrophenol. This study suggested that their porous structure and active Au nanoparticle catalyst allowed fast and mass catalytic functions by simple filtration without washing or catalyst recovery steps. We found no significant damage to the hybrid membrane during the reactions with a few liters; thus, we expect strong bindings of the Au nanoparticles on the surface of the porous LDH.

Optimization of parameters for adsorption of acid yellow 36 dye onto nitrate‐intercalated MgAl LDH nanoparticle using Box–Behnken design

AbstractBACKGROUNDLayered double hydroxide nanoparticles have been extensively investigated and exploited for the removal of harmful anions from contaminated water. For adsorption of acid yellow dye (AY) from contaminated water, nitrate‐intercalated MgAl layered double hydroxide (LDH) nanoparticles were synthesized using the co‐precipitation method with the refluxing condition in a nitrogen atmosphere.RESULTSThe X‐ray diffraction pattern of LDH nanoparticles showed that LDH nanopowder with nitrate in the interlayer position was successfully synthesized. The shift in (003) basal plane diffraction peak to a lower angle (2θ) of 7.75° in the LDH‐AY from 10.40° in the pristine LDH confirmed the intercalation of AY in the interlayer space of LDH. Variable factors for the adsorption of the AY on the LDH nanoparticles were examined in the batch process using ultraviolet–visible spectroscopy and those included the adsorbent dose (5–30 mg), the incubation time (3–60 min), the temperature (25–50 °C), the pH of the AY aqueous suspension (5–9) and the AY concentration (0.03–0.1 mg mL−1). Box–Behnken design was used to optimize the three independent variables of temperature, incubation time and pH of AY solution for the adsorption of the dye. The optimized values of the incubation time, temperature and pH were found to be 25.89 min, 35.99 °C and 5.16, respectively. A maximum adsorption rate of 0.00515 g mg−1 min−1 of AY onto LDH nanoparticles was found at a solution pH of 5 and a temperature of 50 °C. The adsorption kinetics of the AY at different suspension pH values and temperature followed a pseudo‐second‐order kinetic model. Furthermore, an adsorption isotherm study for the adsorption of AY at a temperature of 40 °C and pH 5 followed a Langmuir isotherm model, and the maximum adsorption capacity of the AY was calculated to be 412.55 mg g−1 with excellent regeneration capacity.CONCLUSIONThe study revealed that the synthesized nitrate intercalated Mg Al LDH nanoparticles using the reflux conditions offered promising potential to adsorb acid yellow 36 dye form its aqueous solution. © 2023 Society of Chemical Industry (SCI).

Curcumin in exfoliated layered double hydroxide nanoparticles: Pre-clinical evaluation as lung cancer nanomedicine

Rationally designed ∼ 100 nm sized curcumin (CRC) loaded exfoliated layered double hydroxide nanoparticles (X-LDH/CRC-NPs) have been tested for its suitability as nanomedicine in non-small cell lung cancer (NSCLC) cell lines (A549 and NCI-H460) resulting enhanced apoptosis. Preclinical evaluation on A549 tumor bearing nude mouse model confirmed that such a well-designed X-LDH/CRC NPs would be highly advantageous for treating lung cancers.