Clay Nanoparticles Research Articles

Bio-Inspired Impregnations of Carbon Rovings for Tailored Bond Behavior in Carbon Fiber Reinforced Concrete

Nature provides various templates for integrating organic and inorganic materials to create high-performance composites. Biological structures such as nacre and the structural elements of the glass sponge are built up in layers, leading to remarkable fracture toughness. In this work, the brick-and-mortar and layer-by-layer structures found in these biological examples have been abstracted and implemented by using an aqueous polymer dispersion in combination with nanoclay particles and sodium water glass. These dispersions were used as impregnation of carbon rovings in order to form bio-inspired contact zones towards the concrete matrix. The bonding behavior was investigated using the Yarn Pull-Out (YPO) test, and a beneficial behavior of the layered polymer–nanoclay dispersions was observed. Thermogravimetric analysis (TGA) was used to determine the organic impregnation content of the roving. Further, light microscopy of the roving cross-sections prior to YPO and visual analyses of the fractured contact zone of split concrete specimens provided information on the quality of the impregnation and the interaction with the concrete matrix.

Achieving enhanced tensile properties of polyurethane-multiwall carbon nanotubes nanocomposites

Polymeric nanocomposites have emerged as a promising class of materials with improved strength, stiffness, and toughness compared to pure polymers. The incorporation of nanoparticles into polymer matrices, such as carbon nanotubes, graphene, clay nanoparticles, and metal oxides, has shown considerable potential for enhancing the properties of the produced nanocomposites. Herein, the influence of filtered multiwalled carbon nanotubes (MWCNTs) on solution-cast polyurethane (PU) nanocomposite is explored. Scanning electron microscopy (SEM), x-ray diffraction (XRD), Raman spectroscopy, thermogravimetric analysis (TGA), and x-rays photoelectron spectroscopy (XPS), respectively, were employed to characterize the morphology, crystal structure, phase, thermal stability, and oxidation states of the samples. MWCNTs with a higher weight% of MWCNTs showcased superior mechanical properties compared to base polymer (PU). The nanocomposite with 1 wt% of MWCNTs and 99 wt% of PU exhibited the highest stress (19.25 N mm−2) and strain (700.22%) among all fabricated samples. Also, Modulus of elasticity (∼25%), Ultimate tensile strength (∼21%), and elongation at break (∼11%) are increased by incorporating 0.5 wt% MWCNTs into PU matrix. The attainment of these remarkable mechanical properties could be attributed to excellent dispersion, interfacial bonding and structural stability of filtered MWCNTs in the nanocomposites.

Mequinol-Loaded Nano Clay Drug Carriers in a Gelatin Hydrogel for Wound Healing: An Antiinflammatory and Antioxidant Treatment Modality

In the current study, mequinol was loaded into clay nanoparticles and the resulting nanocarriers were dispersed in a gelatin hydrogel to prepare a potential wound dressing material. The developed nanocomposite hydrogels were characterized regarding their biocompatibility, swelling, radical scavenging activity, swelling potential, and release profile. The healing function of the produce wound dressing was investigated in a rat model of diabetic wound healing. In vitro studies showed that our developed hydrogel was not toxic against the skin cells and was conductive for their adhesion and proliferation. In vivo study showed that mequinol-loaded nanocomposite hydrogels augmented the rate of wound size reduction in diabetic rats by improving wounds’ epithelialization and deposition of collagen fibers.

Effect of fillers and weave architecture hybridization on the impact performance of 3D woven hybrid green composites

AbstractThe eco‐friendly characteristics of green composites not only make them economically and technically viable but also contribute to the reduction of pollution. Green composites are developed by combining degradable fibers (primarily cellulosic materials) with natural resins. A disadvantage of green composites is their lower mechanical strength. To address this issue, 3D woven reinforcement along with fillers can be used to enhance the mechanical properties of green composites. In the current study, three different types of novel 3D woven hybrid structures, that is, hybrid through the thickness (HB‐1 (TT), novel woven layer‐to‐layer structure (HB‐2 (LL)), and layer‐to‐layer structure with double warp yarn (HB‐3 (LL)) were developed. Composites were fabricated using the compression molding technique. Three different concentrations (2%, 5%, and 8%) of nano clay (nanoparticles) were used as fillers and mixed in the green epoxy resin. Pendulum (Charpy) and drop weight impact tests of the composites were performed. The results showed that by the addition of nano particles the impact properties were increased. Nanoparticles showed a significant effect on impact strength. Charpy impact test results showed that the HB‐3 (LL) composite sample with 8% nanofillers showed the highest impact performance, while the HB‐1 (TT) composite sample with 8% nanofillers showed the highest impact performance during the drop weight impact test. By comparing the impact strength of the present work with that of similar research previously published, it is evident that our study achieved a remarkable improvement of 19.17%. This increase is due to the novel structures and nano fillers in the composite.Highlights Eco‐friendly green composites: economically feasible, minimizes pollution. Adding 3D woven structures to green composites improves their mechanical properties. Composite materials with nano clay fillers have increased impact resistance. The highest impact performance is shown by HB‐3 (LL) composites with 8% nanofillers.

Abrasion resistance of a carbon fiber reinforced composite based on a nanoclay epoxy nanocomposite matrix

AbstractIn this paper, the abrasion resistance of a carbon fiber composite based on epoxy nanocomposite matrix filled with layered‐silicate clay nanoparticles was evaluated. In the first step of the work, the clay‐epoxy nanocomposite was first studied to assess the dispersion and the performance, and then to select the best content for the fiber composite production. The nanocomposite mixture was prepared by finely dispersing clay nanoparticles into the epoxy monomer through mechanical stirring, then the hardener was added. After this step, the fiber reinforced composite was produced by vacuum infusion, and then the properties were evaluated. The abrasion resistance has been assessed using different approaches. A test was specifically designed to simulate the impact of abrasive powders which could potentially be found in the atmosphere and crash into aircraft or air vehicles (such as for instance volcanic ashes). The results showed that the presence of nanoclay reduces the weight loss of the sample with the impacted surface, which can be clearly correlated to a damage reduction.Highlights Sandblasting tool made to mimic impact of abrasive powder on composite surface Presence of nanoclay does not significantly affect the vacuum infusion process Layered‐silicate nanoparticles lead to improve composites abrasion resistance

Fabrication of magnetic nanocomposite scaffolds based on polyvinyl alcohol-chitosan containing hydroxyapatite and clay modified with graphene oxide: Evaluation of their properties for bone tissue engineering applications

One of the most common systems for bone tissue engineering is polymeric scaffolds. However, the low mechanical properties of polymeric scaffolds, considering the properties required for bone replacement tissue, are the main challenge for researchers in this field. For bone tissue engineering, this research prepared nanocomposite scaffolds based on polyvinyl alcohol-chitosan containing modified clay and hydroxyapatite (HAp). HAp used in these 3D scaffolds was synthesized from a chicken femur, and Cloisite 30B clay nanoparticles were modified by graphene oxide and Fe3O4 nanoparticles to strengthen their mechanical properties. Sample characteristics were determined using FT-IR, XRD, SEM, TGA, swelling rate, laboratory degradation, and biological and mechanical properties. These analyses showed that 2% of modified clay (C30B/GO/Fe3O4, CGF) inside the nanocomposite scaffold increased the compressive strength 23 times compared to the pristine polymer scaffold. Also, adding HAp particles and modified clay simultaneously increased the mineralization on the surface of the scaffolds. Final nanocomposite scaffolds were found to have a compressive strength of 9.31 MPa, a porosity of 75 %, and a porosity size of 50 nm and were in the range of cancellous bone. The final swelling amount is 1790 %, which is the amount that is Favorable for bone scaffold. Finally, the analysis results to determine the samples' toxicity showed that none of the prepared scaffolds were toxic and showed good cell viability.

Enhancing asphaltic mixtures with Calcined Nano Montmorillonite: A performance assessment

There are increasing interest in using nanoclay particles to improve asphalt binder and the produced concrete in pavement engineering. However so far most of the study was to directly use the nanoclays in natural material conditions, which come with some inefficient factors affecting the final effectiveness of the modified asphalt binder and the made concrete. This paper reports extensive experimental research on using preprocessed nanoclay, the Calcined Nano Montmorillonite (CNMM), to modify asphalt binder, compared with using natural Nano Montmorillonite (NMM). The nanoclays were added in asphalt as additive at different content rates ranging from 0% to 10% by the weight of asphalt binder. Experimental tests were performed on both of the modified asphalt binders and the concrete mixes using them. The study showed that at a 10% content CNMM demonstrated 32% improvement on Indirect Tensile Strength (ITS), and 5.25% less permanent deformation after exposed 10,000 load repetitions; at 6% CNMM presented 57.5% improvement on the CTindex for fatigue resistance. Meanwhile, the SEM analysis proved a distinctive morphological difference between NMM and CNMM, which indicates the optimized microscopic structure of the CNMM for the improvement on the interlock and adhesion with asphalt binder. In comparison, the optimum dosage for NMM is identified at 4%, while CNMM is at around 6%. The economic viability of the use of CNMM against the use of NMM has also been discussed in reference to the local material prices. In consideration of a balance between cost and performance, 6% content is recommended for the use of CNMM.

Experimental investigation into effects of the natural polymer and nanoclay particles on the EOR performance of chemical flooding in carbonate reservoirs

This paper aims to investigate the tragacanth gum potential as a natural polymer combined with natural clay mineral (montmorillonite, kaolinite, and illite) nanoparticles (NPs) to form NP–polymer suspension for enhanced oil recovery (EOR) in carbonate reservoirs. Thermal gravimetric analysis (TGA) tests were conducted initially in order to evaluate the properties of tragacanth gum. Subsequently, scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) tests were used to detect the structure of clay particles. In various scenarios, the effects of natural NPs and polymer on the wettability alteration, interfacial tension (IFT) reduction, viscosity improvement, and oil recovery were investigated through contact angle system, ring method, AntonPaar viscometer, and core flooding tests, respectively. The entire experiment was conducted at 25, 50, and 75 °C, respectively. According to the experimental results, the clay minerals alone did not have a significant effect on viscosity, but the addition of minerals to the polymer solution leads to the viscosity enhancement remarkably, resulting mobility ratio improvement. Among clay NPs, the combination of natural polymer and kaolinite results in increased viscosity at all temperatures. Considerable wettability alteration was also observed in the case of natural polymer and illite NPs. Illite in combination with natural polymer showed an ability in reducing IFT. Finally, the results of displacement experiments revealed that the combination of natural polymer and kaolinite could be the best option for EOR due to its substantial ability to improve the recovery factor.

Development of multilayer PVA-MMT and PVA-CS film structures by spin coating-assisted layer-by-layer technique: Effect of PVA, CS and MMT nanoclay orientation on oxygen barrier properties

The orientation of biopolymer macromolecules and nanoclay, specifically Montmorillonite (MMT) nanoplatelets, plays a crucial role in controlling the properties of multi-layer film structures. Understanding the impact of macromolecule and nanoclay platelets’ orientation on barrier properties of packaging films is essential. To investigate the influence of hydrogen bonding in multilayer films structures, two polymers, namely polyvinyl alcohol (PVA) and chitosan (CS), were selected and laminated nanocomposite films were fabricated using the spin coating-assisted layer-by-layer (Spin-LbL) assembly technique. This technique facilitates the production of highly oriented nanocomposite films, where polymer chains and nanoclay particles align parallel to the film surface. Multi-directional 2-D wide-angle X-ray diffraction (2D-WADX) was successfully used to accurately assess the orientation and distribution of MMT nanoplatelets. Additionally, the films underwent characterization using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The 2D-WADX analysis revealed a parallel alignment of both the PVA chains and MMT clay nanoplatelets parallel to film surface. The XRD results confirmed the formation of intercalated nanolaminate structures, hydrogen-bonding interactions, and adjustments in the crystalline structure of PVA matrix. Through contact angle and oxygen permeability measurements, we observed that all quadri-layer film structures exhibited hydrophobic properties and reduced oxygen permeability compared to neat PVA films. Furthermore, the integration of MMT nanoclay, even at low concentrations, contributed to the development of nanocomposite films with improved oxygen barrier properties. Consequently, the quadri-layer films demonstrate great potential for food packaging applications.

Effect of Nano-Clay Dispersion on Pore Structure and Distribution of Hardened Cement Paste

Nano-clay has the potential to improve the properties of cement-based materials. However, the effectiveness of this improvement is influenced by the dispersion of the nano-clay. The effects of different nano-clay dispersion techniques on cement-based material properties and pore structure complexity were studied. The samples were prepared using manual and mechanical dispersion methods. The mechanical properties of the specimens were evaluated, and the pore characteristics of the cement-based materials were analysed using mercury intrusion porosimetry. The study investigated the effect of the dispersion method on the nano-clay dispersion. The complexity of the pore structure was evaluated using a fractal model, and the relationship between the fractal dimension, mechanical properties, and pore structure was analysed. The findings indicate that mechanical dispersion results in better dispersion than manual dispersion, and the mechanical properties of mechanical dispersion are superior to those of manual dispersion. Nano-clay particles can improve the internal pore structure of cement materials. Through mathematical calculation, the surface fractal dimension is between 2.90 and 2.95, with good fractal characteristics. There is a good correlation between the surface fractal dimension and the mechanical properties. The addition of nano-clay can reduce the complexity of the pore structure, and the fractal dimension has an excellent linear relationship with the pore structure.

Improvement of mechanical and wear properties of epoxy/glass fiber/Titanium Carbide+Titanium diborides hybrid composites by adding clay nanoparticles

In previous work, despite the positive effect of the titanium carbide + titanium diboride (TiC+TiB2) on the wear, hardness and erosion properties of the epoxy/glass fiber composites, the particles reduced tensile and flexural strength. This research targets to improve the tensile and flexural properties of the epoxy/glass fiber/TiC+TiB2 composites by adding clay nanoparticles in content of 1, 3, and 5 wt%. The effect of nano-clay content on mechanical (tensile, flexural, and hardness) properties and wear behavior of the hybrid composites was investigated. The field Emission Scanning Electron Microscopy (FE-SEM) images revealed the morphology, the fracture surface and failure mechanisms of the composites. The X-ray diffraction confirmed the formation of TiC+TiB2 particles and the nanocomposites. Tensile and flexural results showed that introducing clay nanoparticles increases tensile strength and flexural strength by 92% (from 116 to 223 MPa) and 67% (from 194 to 324 MPa), respectively. The nano-clay did not have a significant effect on the tensile and flexural modulus. The hardness increased from 35.1 to 79.4 HRP. Wear properties results revealed that clay nanoparticles improve the wear resistance of the composite samples significantly. The addition of 5 wt% of clay nanoparticles decreased wear rate from 3.7 to 0.4 mg/Nm.

Self-Assembly of Structured Colloidal Gels for High-Resolution 3D Micropatterning of Proteins at Scale.

Self-assembly, the spontaneous ordering of components into patterns, is widespread in nature and fundamental to generating function across length scales. Morphogen gradients in biological development are paradigmatic as both products and effectors of self-assembly and various attempts have been made to reproduce such gradients in biomaterial design. To date, approaches have typically utilized top-down fabrication techniques that, while allowing high-resolution control, are limited by scale and require chemical cross-linking steps to stabilize morphogen patterns in time. Here, a bottom-up approach to protein patterning is developed based on a novel binary reaction-diffusion process where proteins function as diffusive reactants to assemble a nanoclay-protein composite hydrogel. Using this approach, it is possible to generate scalable and highly stable 3D patterns of target proteins down to sub-cellular resolution through only physical interactions between clay nanoparticles and the proteins and ions present in blood. Patterned nanoclay gels are able to guide cell behavior to precisely template bone tissue formation in vivo. These results demonstrate the feasibility of stabilizing 3D gradients of biological signals through self-assembly processes and open up new possibilities for morphogen-based therapeutic strategies and models of biological development and repair.

An Evaluation of Experimental Calcium Ion-Leachable Nanocomposite Glass Ionomer Cements.

Glass ionomer cements (GICs) are among the main restorative dental materials used broadly in daily clinical practice. The incorporation of clay nanoparticles as reinforcing agents is one potential approach to improving GIC properties. This study aims to investigate whether the incorporation of calcium-modified clay (Ca-clay) nanoparticles in conventional GICs alters their structural characteristics, along with their physicochemical and mechanical properties. Scanning electron microscopy (SEM) and X-ray diffraction (XRD) analyses were performed to assess the surface characterization of GIC nanocomposites, whereas a setting reaction was carried out via an attenuated total reflection Fourier transform infrared spectrometer (ATR-FTIR). A universal testing machine was used for compression tests, while calcium ion release was quantified using inductively coupled plasma optical emission spectrometry (ICP-OES). GIC composite groups reinforced with Ca-clay were found to release a fine amount of calcium ions (5.06-9.91 ppm), with the setting reaction being unaffected for low Ca-clay loadings. The median compressive strength of 3 wt% in the Ca-clay group (68.97 MPa) was nearly doubled compared to that of the control group (33.65 MPa). The incorporation of Ca-clay nanoparticles in GICs offers a promising alternative among dental restorative materials regarding their chemical and mechanical properties.

Nanoscale Prediction of the Thermal, Mechanical, and Transport Properties of Hydrated Clay on 106- and 1015-Fold Larger Length and Time Scales.

Coupled thermal, hydraulic, mechanical, and chemical (THMC) processes, such as desiccation-driven cracking or chemically driven fluid flow, significantly impact the performance of composite materials formed by fluid-mediated nanoparticle assembly, including energy storage materials, ordinary Portland cement, bioinorganic nanocomposites, liquid crystals, and engineered clay barriers used in the isolation of hazardous wastes. These couplings are particularly important in the isolation of high-level radioactive waste (HLRW), where heat generated by radioactive decay can drive the temperature up to at least 373 K in the engineered barrier. Here, we use large-scale all-atom molecular dynamics simulations of hydrated smectite clay nanoparticle assemblages to predict the fundamental THMC properties of hydrated compacted clay over a wide range of temperatures (up to 373 K) and dry densities relevant to HLRW management. Equilibrium simulations of clay-water mixtures at different hydration levels are analyzed to quantify material properties, including thermal conductivity, heat capacity, thermal expansion, suction, water and ion self-diffusivity, and hydraulic conductivity. Predictions are validated against experimental results for the properties of compacted bentonite clay. Our results demonstrate the feasibility of using atomistic-level simulations of assemblages of clay nanoparticles on scales of tens of nanometers and nanoseconds to infer the properties of compacted bentonite on scales of centimeters and days, a direct upscaling over 6 orders of magnitude in space and 15 orders of magnitude in time.

Ligand-Directed Shape Reconfiguration in Inorganic Materials.

Polymer elastomers with reversible shape-changing capability have led to significant development of artificial muscles, functional devices, and soft robots. By contrast, reversible shape transformation of inorganic nanoparticles is notoriously challenging due to their relatively rigid lattice structure. Here, the authors demonstrate the synthesis of shape-changing nanoparticles via an asymmetrical surface functionalization process. Various ligands are investigated, revealing the essential role of steric hindrance from the functional groups. By controlling the unbalanced structural hindrance on the surface, the as-prepared clay nanoparticles can transform their shape in a fast, facile, and reversible manner. In addition, such flexible morphology-controlled mechanism provides a platform for developing self-propelled shape-shifting nanocollectors. Owing to the ion-exchanging capability of clay, these self-propelled nanoswimmers (NS) are able to autonomously adsorb rare earth elements with ultralow concentration, indicating the feasibility of using naturally occurring materials for self-powered nanomachine.

Compressive and Tensile Strength of Nano-clay Stabilised Soil Subjected to Repeated Freeze–Thaw Cycles

Abstract Improvement of the mechanical properties of clayey soils by additional elements to enhance the strength under numerous freezing and thawing cycles has been considered as a serious concern for engineering applications in cold regions. The objective of the current study is to investigate the effect of nano-clay as a stabiliser on the mechanical properties of clay. To this end, the clay specimens were prepared by adding various percentages of nano-clay ranging from 0.5% to 3% by dry weight of soil and were experimentally tested under the uniaxial compression and tensile splitting tests under different curing times (0, 7 and 28 days) after experiencing various freeze–thaw cycles ranging from 0 to 11. It can be concluded from the results that nano-clay particles may be used as a stabiliser in geotechnical applications to improve soil property. The results indicate that the optimum moisture content (OMC) of specimens increases and the maximum dry density (MDD) decreases with the increasing nano-clay content. The specimens containing about 1% nano-clay recorded maximum values of unconfined compressive strength (UCS) as well as tensile strength. For example, the addition 1% nano-clay increased the UCS and tensile values of clay specimens under the curing time of 28 days by 34% and 247%, respectively. In addition, the long-term durability of specimens against freeze–thaw cycles increases further with the addition of nano-clay content ranging from 2% to 3%.

Fabrication of Bio-Nanocomposite Packaging Films with PVA, MMt Clay Nanoparticles, CNCs, and Essential Oils for the Postharvest Preservation of Sapota Fruits.

Sapota is an important climacteric fruit with limited shelf life. A special system must be employed to extend the shelf life of sapota fruits. In the present study, polyvinyl alcohol (PVA) and montmorillonite clay (MMt)-based bio-nanocomposite films (BNFs) were integrated at various concentrations (2%, 4%, 6%, and 8%) into cellulose nanocrystals (CNCs), produced from garlic peels (GPs). The BNF loaded with 8% CNC has a better crystallinity index and mechanical properties than the other concentrations of CNC. Therefore, the 8% CNC-incorporated BNF (BNF-8) was selected for further packaging studies. The combined effect of BNF-8 with ajwain essential oil (AO) and oregano essential oil (OO) vapors and BNF-8 with carbendazim (commercial fungicide-CARB) were investigated. In this study, the BNF-based packagings are categorized into five types, viz: BNF+8% CNC (BNF-8), BNF-8+AO, BNF-8+OO, BNF-8+CARB and the non-packaged fruits (control). The shelf-life duration, antioxidant activity, firmness, decay index, and sensory quality were evaluated in order to identify the effectiveness of packaging treatment on sapota fruits. BNF-8+CARB, BNF-8+AO, and BNF-8+OO packaging extended the shelf life of sapota fruits to up to 12 days and maintained the overall physiochemical parameters and sensory qualities of the fruits. Therefore, the BNF-8+AO and BNF-8+OO packaging materials are appropriate alternatives to commercial fungicides for the preservation of sapota during postharvest storage.

Influence of different nanoparticles on the gas injection performance in EOR operation: Parametric and CFD simulation study

AbstractThis study aims to simulate the process of enhanced oil recovery (EOR) during gas injection along with nanoparticles and investigate the affecting parameters in a conventional carbonate oil reservoir. Ansys Fluent software with a suitable multiphase model was used to simulate natural gas injection with a nanoparticle into a core sample. The simulation model was validated with a laboratory test of natural gas injection. Then, to obtain the optimal values of each of the parameters affecting the process of EOR during the natural gas injection along with nanoparticles, the design of the experiment was carried out with the help of Qualitek‐4 software and the Taguchi method. Therefore, three factors, including nanoparticle type (clay, titanium oxide, and silica nanoparticles), nanoparticle diameter (2–50 nm), and the volume fraction of nanoparticles in the base fluid (0.5–5 vol.%), as influential factors on the EOR during natural gas injection along with nanoparticles were chosen. The results of the numerical study indicated that silica nanoparticles significantly affect EOR more than clay and titanium oxide nanoparticles. Moreover, the smaller the diameter of nanoparticles (close to 2 nm) and the more significant the volume fraction of nanoparticles in the base fluid (close to 5 vol.%), the higher the oil recovery factor will be. This phenomenon occurs due to changes in the density and viscosity of the base fluid and, consequently, improves the mobility ratio of the injected fluid. On the other hand, the tiny size of nanoparticles allows them to easily enter the pores of the reservoir rock without entrapping and producing oil from them. Eventually, the highest oil recovery factor (59%) was obtained using silica nanoparticles with a diameter of 2 nm and a volume fraction of 5 vol.% in natural gas injection.

Nanoclay Drug-Delivery System Loading Potassium Iodide Promotes Endocytosis and Targeted Therapy in Anaplastic Thyroid Cancer.

The rapid proliferative biological behavior of primary foci of anaplastic thyroid cancer (ATC) makes it a lethal tumor. According to the specific iodine uptake capacity of thyroid cells and enhanced endocytosis of ATC cells, we designed a kind of nanoclay drug-loading system and showed a promising treatment strategy for ATC. Introducing potassium iodide (KI) improves the homoaggregation of clay nanoparticles and then affects the distribution of nanoparticles in vivo, which makes KI@DOX-KaolinMeOH enriched almost exclusively in thyroid tissue. Simultaneously, the improvement of dispersibility of KI@DOX-KaolinMeOH changes the target uptake of ATC cells by improving the endocytosis and nanoparticle-induced autophagy, which regulate the production of autolysosomes and autophagy-enhanced chemotherapy, eventually contributing to a tumor inhibition rate of more than 90% in the primary foci of ATC. Therefore, this facile strategy to improve the homoaggregation of nanoclay by introducing KI has the potential to become an advanced drug delivery vehicle in ATC treatment.

On the mechanical properties and vibrational characteristics of the nanoparticle-reinforced composite cylindrical panels in the acidic environment: Numerical and experimental investigation

The purpose of this study is to determine the impact of nano-clay and nano-silica particles on the vibrational characteristics of composite cylindrical panels in corrosive environments. In this context, due to the presence of diluted sulfuric acid as the corrosive solution, the coupling effects of material degradation and hygroscopic loading on the natural frequencies are taken into consideration. In order to achieve this, it is first explored through experiment how adding nanoparticles affects the coefficient of hygroscopic expansion of the glass/epoxy specimens. Using this coefficient, the in-plane loading caused by corrosive solution is then applied in the equations. The mechanical properties and hygroscopic expansion coefficients of the composite samples exposed to the corrosive environment are first determined by certain experimental testing. The equations of motion are derived using the first-order shear deformation theory (FSDT), and the vibration problem is solved using the generalized differential quadrature (GDQ) technique. Investigation is conducted into the effects of various nanoparticles, immersion time, geometrical elements, and boundary conditions on the natural frequencies of the cylindrical panels. It is found that adding nanoparticles can significantly improve the mechanical properties, the corrosion resistance, and the natural frequencies of composites in which the nano-clay is more effective. For example, adding nano-clay and nano-silica particles, respectively, results in 32.32% and 26.29% increase in elasticity modulus of reinforced glass/epoxy composite. In addition, 12.71% and 47.32% improvements are observed in the natural frequency of the nano-clay reinforced composite panel before and after 90 days of immersion in sulfuric acid. In comparison, the nano-silica particles are responsible for 7.80% and 23.03% increase in natural frequency before and after immersion time.