Nanocomposite System Research Articles

Optical and sign-flipping nonlinear optical properties of NiO/PMMA/PANI nanocomposite films

In this study, we introduce an efficient nanocomposite system to enhance optical properties of Nickel oxide (NiO) integrated with two polymers matrix. NiO nanoparticles is prepared using chemical co-precipitation method and its nanocomposite films (NCFs) were prepared with poly methyl methacrylate (PMMA) and polyaniline (PANI) using drop-casting method on glass substrate and was optimized by changing the concentration of NiO. The prepared NCFs were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), ultraviolet (UV)-visible absorption spectroscopy, photoluminescence (PL) spectroscopy and X-ray photoelectron (XPS) spectroscopy. The open-aperture z-scan method is employed for nonlinear optical investigations, utilizing a nanosecond pulsed laser with a wavelength of 532 nm for excitation. The findings indicate that the NCFs exhibit sign-flipping nonlinear behavior, indicating a transition from saturable absorption to reverse saturable absorption. This suggests that our NCFs exhibit optical limiting properties and potential for applications in photonic devices, such as optical switches and laser protection systems.

Advanced Two-Stage Nanocomposite Membrane System for Methane and Carbon Dioxide Separation from Atmospheric Air

This paper presents an advanced two-stage nanocomposite membrane system designed to efficiently separate and capture methane (CH4) and carbon dioxide (CO2) from atmospheric air and water sources. The membrane system comprises a CO2-selective primary membrane and a CH4-selective secondary membrane, utilizing a hierarchical nanomaterials and polymers structure. The proposed system demonstrates unprecedented versatility, operating effectively across an extensive range of gas concentrations (>20% to <0.02%) and reducing CH4 levels from 100-500 ppm to 5-10 ppm in both aerobic and anaerobic conditions. Performance metrics specify CO2 permeances of 200-2000 GPU and CO2/N2 selectivities of 30-500 at 57 °C and 1 atm feed pressure, surpassing the Robeson upper bound for traditional polymer membranes. The CH4-selective membrane achieves 500-2000 GPU permeances with CH4/CO2 selectivities >50. Furthermore, experimental validation over 1000 hours of continuous operation demonstrated 92% methane capture efficiency under challenging conditions (55 tons/hour methane content at 30 °C). The system's energy consumption of 0.3 kWh/kg of CH4 captured underscores its efficiency compared to traditional methods. This innovative membrane technology offers a promising solution for addressing critical ecological and industrial challenges associated with greenhouse gas emissions in the 21st century.

Reinforcement effects of graphene oxide in polyamide 6 nanocomposite system synthesized by in-situ polymerization

In this study, the excellent enhancement in the mechanical properties and thermal properties of polyamide 6 (PA6) by the incorporation of very low content of graphene oxide (GO) was achieved. For example, the Young's modulus of PA6/GO nanocomposites with 0.5 wt% GO was 138 % higher than that of PA6. In addition, the thermal decomposition temperature increased from 341 °C of PA6 to 361 °C by the addition of only 0.5 wt% of GO. The detailed effect of GO on the structure (e.g. dispersibility, orientation, alignment, crystallinity, interfacial interactions) of the nanocomposites were investigated. Understanding the reinforcing effect of GO and its mechanism is important for the designing of polymer nanocomposites which can provide strong candidates for light weight and smart applications in various fields.

A novel polymer nanocomposite system for rapid dimethyl phthalate toxicity removal

A novel polymer nanocomposite system for rapid dimethyl phthalate toxicity removal

Mixed Systems of Quaternary Ammonium Foam Drainage Agent with Carbon Quantum Dots and Silica Nanoparticles for Improved Gas Field Performance.

Foam drainage agents enhance gas production by removing wellbore liquids. However, due to the ultra-high salinity environments of the Hechuan gas field (salinity up to 32.5 × 104 mg/L), no foam drainage agent is suitable for this gas field. To address this challenge, we developed a novel nanocomposite foam drainage system composed of quaternary ammonium and two types of nanoparticles. This work describes the design and synthesis of a quaternary ammonium foam drainage agent and nano-engineered stabilizers. Nonylphenol polyoxyethylene ether sulfosuccinate quaternary ammonium foam drainage agent was synthesized using maleic anhydride, sodium chloroacetate, N,N-dimethylpropylenediamine, etc., as precursors. We employed the Stöber method to create hydrophobic silica nanoparticles. Carbon quantum dots were then prepared and functionalized with dodecylamine. Finally, carbon quantum dots were incorporated into the mesopores of silica nanoparticles to enhance stability. Through optimization, the best performance was achieved with a (quaternary ammonium foam drainage agents)-(carbon quantum dots/silica nanoparticles) ratio of 5:1 and a total dosage of 1.1%. Under harsh conditions (salinity 35 × 104 mg/L, condensate oil 250 cm3/m3, temperature 80 °C), the system exhibited excellent stability with an initial foam height of 160 mm, remaining at 110 mm after 5 min. Additionally, it displayed good liquid-carrying capacity (160 mL), low surface tension (27.91 mN/m), and a long half-life (659 s). These results suggest the effectiveness of nanoparticle-enhanced foam drainage systems in overcoming high-salinity challenges. Previous foam drainage agents typically exhibited a salinity resistance of no more than 25 × 104 mg/L. In contrast, this innovative system demonstrates a superior salinity tolerance of up to 35 × 104 mg/L, addressing a significant gap in available agents for high-salinity gas fields. This paves the way for future development of advanced foam systems for gas well applications with high salinity.

Clay Nanosheet-Based Nanocomposite Supramolecular Hydrogel Enabling Rapid, Reversible Phase TransitionOnly withVisible Light.

High mechanical properties and rapid sol/gel phase transition are mutually exclusivein the hydrogels reported to date, most likely because the 3D crosslinked networks of mechanicallyrobust hydrogels comprise bundled thick fibers that are not rapidly dissociable or formable.Herein, we report a visible light-responsive hydrogelthatshowed a rapid, reversible sol/gel phase transition despite its relatively high mechanical properties (storage modulus ~1000Pa).To construct its 3D crosslinked network, we used a design strategy analogous to that employed for our highly water-rich yet mechanically robust nanocomposite supramolecular hydrogel("aqua material").In this case, multiple poly(ethylene glycol) chains carryingortho-tetramethoxyazobenzenetermini (AzoPEG) were noncovalently crosslinked by clay nanosheets (CNSs) with surface-immobilizedβ-cyclodextrin units using their seven guanidinium ion(Gu+) pendants (GuCD)via a multivalent salt-bridge.Whenexposed to visible light at 625 and 450 nm, the azobenzene termini isomerized fromtrans-to-cisandcis-to-trans, respectively, and were detached from and attached to the surface-immobilizedGuCD units.The advantage of thisCNS-based nanocomposite supramolecular system is its simple 3D network structure, which formsand breaksrapidly without slow chain entangling and disentangling processes.

Evaluation, optimization study, and life cycle assessment of novel eco-friendly PVA-based nanocomposite hydrogel adsorbents for methylene blue and paracetamol removal

In this study, an eco-friendly and novel hydrogel based on a crosslinked polyvinyl alcohol (PVA), iota carrageenan (IC) and polyvinylpyrrolidone (PVP) scaffold, containing a large amount (10–50 wt%) of nanoscale palm fronds (NPF) as additives, for water purification was demonstrated. A life cycle assessment (LCA) findings on NPF as biomass waste incorporated into PVA_PVP_IC polymer matrix was presented, and the results highlight the necessity of focused actions to reduce environmental impact and support the palm waste utilization in a sustainable manner. The multicomponent nanocomposite hydrogels were examined as adsorbents in a system work in batches for methylene blue (MB) and paracetamol (PCT) removal. The results show that, the presence of NPF, which dispersed in the hydrogel PVA_PVP_IC scaffolds containing both covalent and non-covalent cross-linking bonds, greatly enhanced the MB and PCT adsorption efficiency. A response surface methodology (RSM) model was used to find the best operating parameters of contaminant adsorption, including time, adsorbent dose, and starting concentration of pollutants. By using this statistical model, it was found that the optimal conditions for the adsorption reaction to achieve the complete removal of MB are 66.7 h adsorption time duration, 98.5 mg L−1 starting concentration, and an adsorbent dose of 5.9 mg, while for the complete removal of PCT, it is 57.6 h adsorption time duration, 80 mg L−1 starting concentration, and an adsorbent dose of 6 mg. The reusability of the nanocomposite hydrogels were tested for 5 cycles, all showed high adsorption capacity, indicating the potential for practical application of this nanocomposite hydrogel system. This study indicates that the prepared nanocomposite hydrogel raises the standard used for treatment of wastewater and also gives a solution to protect the environment and mitigate global warming.

Clay Nanosheet‐Based Nanocomposite Supramolecular Hydrogel Enabling Rapid, Reversible Phase Transition Only with Visible Light

High mechanical properties and rapid sol/gel phase transition are mutually exclusive in the hydrogels reported to date, most likely because the 3D crosslinked networks of mechanically robust hydrogels comprise bundled thick fibers that are not rapidly dissociable or formable. Herein, we report a visible light‐responsive hydrogel that showed a rapid, reversible sol/gel phase transition despite its relatively high mechanical properties (storage modulus ~1000 Pa). To construct its 3D crosslinked network, we used a design strategy analogous to that employed for our highly water‐rich yet mechanically robust nanocomposite supramolecular hydrogel ("aqua material"). In this case, multiple poly(ethylene glycol) chains carrying ortho‐tetramethoxyazobenzene termini (AzoPEG) were noncovalently crosslinked by clay nanosheets (CNSs) with surface‐immobilized β‐cyclodextrin units using their seven guanidinium ion (Gu+) pendants (GuCD) via a multivalent salt‐bridge. When exposed to visible light at 625 and 450 nm, the azobenzene termini isomerized from trans‐to‐cis and cis‐to‐trans, respectively, and were detached from and attached to the surface‐immobilized GuCD units. The advantage of this CNS‐based nanocomposite supramolecular system is its simple 3D network structure, which forms and breaks rapidly without slow chain entangling and disentangling processes.

Engineering Triphasic Nanocomposite Coatings on Pretreated Mg Substrates for Biomedical Applications.

Biodegradable polymer-based nanocomposite coatings provide multiple advantages to modulate the corrosion resistance and cytocompatibility of magnesium (Mg) alloys for biomedical applications. Biodegradable poly(glycerol sebacate) (PGS) is a promising candidate used for medical implant applications. In this study, we synthesized a new PGS nanocomposite system consisting of hydroxyapatite (HA) and magnesium oxide (MgO) nanoparticles and developed a spray coating process to produce the PGS nanocomposite layer on pretreated Mg substrates, which improved the coating adhesion at the interface and their cytocompatibility with bone marrow derived mesenchymal stem cells (BMSCs). Prior to the spray coating process of polymer-based nanocomposites, the Mg substrates were pretreated in alkaline solutions to enhance the interfacial adhesion strength of the polymer-based nanocomposite coatings. The addition of HA and MgO nanoparticles (nHA and nMgO) to the PGS matrix, as well as the alkaline pretreatment of the Mg substrates, significantly enhanced the interfacial adhesion strength when compared with the PGS coating on the nontreated Mg control. The average BMSC adhesion densities were higher on the PGS/nHA/nMgO coated Mg than the noncoated Mg controls under direct contact conditions. Moreover, the addition of nHA and nMgO to the PGS matrix and coating the nanocomposite onto Mg substrates increased the average BMSC adhesion density when compared with the PGS/nHA/nMgO coated titanium (Ti) and PGS coated Mg controls under direct contact. Therefore, the spray coating process of PGS/nHA/nMgO nanocomposites on Mg substrates or other biodegradable metal substrates could provide a promising surface treatment strategy for biodegradable implant applications.

Functional UV Blocking and Superhydrophobic Coatings Based on Functionalized CeO2 and Al2O3 Nanoparticles in a Polyurethane Nanocomposite.

Water repellency has significant potential in applications like self-cleaning coatings, anti-staining textiles, and electronics. This study introduces a novel nanocomposite system incorporating functionalized Al2O3 and CeO2 nanoparticles within a polyurethane matrix to achieve hydrophobic and UV-blocking properties. The nanoparticles were functionalized using an octadecyl phosphonic acid solution and characterized by FTIR and XPS, confirming non-covalent functionalization. Spin-coated polyurethane coatings with functionalized and non-functionalized Al2O3, CeO2, and binary Al2O3-CeO2 nanoparticles were analyzed. The three-layered Al2O3-CeO2-ODPA binary system achieved a contact angle of 166.4° and 85% transmittance in the visible range. Incorporating this binary functionalized system into a 0.4% w/v polyurethane solution resulted in a nanocomposite with 75% visible transmittance, 60% at 365 nm UV, and a 147.7° contact angle after three layers. These findings suggest that ODPA-functionalized nanoparticles, when combined with a polymer matrix, offer a promising approach to developing advanced hydrophobic and UV-protective coatings with potential applications across various industrial sectors.

Lithium Chloride-Mediated enhancement of dye removal capacity in Borneo bamboo derived nanocellulose-based nanocomposite membranes (NCMs)

Demand for sustainable materials for membrane fabrication is rapidly increasing, particularly in Sarawak coastal areas. nanocellulose emerges as a promising alternative for membrane development due to its availability, intrinsic biodegradability, and high strength. However, the hydrophobicity of nanocellulose limits its applicability in water treatment operations. Hence necessitating the need for innovative solutions. Herein, we examine the potential of bamboo-derived nanocellulose to enhance nanocomposite membrane-based water treatment systems by incorporating lithium chloride as a pore-forming additive. Nanocomposite membranes (NCMs) were synthesised using a LiCl-doped solution of nanocellulose and polyvinylidene fluoride (PVDF) through phase inversion and controlled solidification methods. The results show that nanocellulose incorporation induces structural alterations in NCMs, with reduced size in cellulose microfibrils. The crystallinity of nanocellulose was enhanced through interactions between PVDF and nanocellulose. The integration of nanocellulose along with lithium chloride was observed to have a significant impact on water permeation flux, attaining 104 L/m2h due to improved hydrophobicity and reduced fouling. In addition, the developed NCMs recorded 93 % methylene blue (MB) removal within 10 min. Revealing high potential of NCMs as an alternative and sustainable material for the development of nanocomposite membranes to mitigate contemporary challenges of water scarcity.

Promising ferroelectric and piezoelectric response of Cr-doped ZnO nanofiller-incorporated PVDF flexible and laminated nanocomposite system.

Cr3+-doped ZnO (CZ) nanoparticles are prepared using hydrothermal and co-precipitation techniques. The desired crystallographic phase of the nanoparticles is confirmed using X-ray diffraction study. Rod-shaped and spherical morphologies of CZ nanoparticles prepared using hydrothermal and co-precipitation techniques were confirmed through FESEM observation. Each type of nanoparticle was taken separately in PVDF to understand the characteristic properties, such as dielectric, piezoelectric, and ferroelectric properties of the resultant CZ-PVDF nanocomposite films. All the nanocomposite films comprising rod-shaped or spherical CZ nanoparticles show butterfly loops with a low leakage current density of 10-5 A m-2 at a maximum electric field of 100 kV m-2 under J-E measurement. These findings suggest that the polarization property of CZ-PVDF nanocomposite films can be obtained at a high external electric field without causing electric breakdown in the samples. Dielectric permittivity as a function of temperature increases with an increase in the loading percentage of both rod-shaped or spherical CZ nanofillers in PVDF. Polarization response also improves with an increase in the loading percentage of CZ nanofillers in PVDF. In particular, the rod-shaped CZ nanofillers in PVDF with a higher loading percentage (CZHP2) result in a maximum polarization of (10 ± 0.29) × 10-4 μC cm-2, remanent polarization of (2 ± 0.04) × 10-4 μC cm-2, and coercive field of (10 ± 0.1) kV cm-1 at a maximum electric field of 50 kV cm-1. The CZHP2 nanocomposite film has a piezoelectric coefficient (d33) of (25 ± 0.24) pC N-1 and a power density of 1278.90 W m-3. These results indicate that the nanocomposite films have potential application in piezoelectric energy harvesters, offering a possible solution to the energy issue faced by modern society.

CoO nanoparticles anchored on porous pinecone-derived activated carbon as anodes for high-performance lithium and sodium-ion batteries

In this work, a new nanocomposite system based on CoO nanoparticles (NPs) anchored on pinecone-derived activated carbon (PAC), denoted as CoO(x)@PAC, is synthesized by facile ball-milling and sonication processes followed by annealing. H3PO4 is employed as an activation agent to activate the porous carbon derived from pinecone. The loading amount of CoO is varied to obtain the optimum electrochemical performances. Among the nanocomposites, the CoO(20)@PAC delivers a discharge capacity of 886 mA h g−1 after 100 cycles at a current density of 100 mA g−1 when employed as an anode in lithium-ion batteries (LIBs). At higher current rate of 1000 mA g−1, the anode provides an enhanced discharge capacity of 456.6 mA h g−1 after 200 cycles with 99 % capacity retention compared to the 4th cycle capacity. In sodium-ion batteries (SIBs), the CoO(20)@PAC anode delivers a discharge capacity of 290 mA h g−1 at 50 mA g−1. The same nanocomposite anode provides a discharge capacity of 120 mA h g−1 after 900 cycles at a current density of 500 mA g−1. The CoO(20)@PAC nanocomposite shows a great potential as an anode for both LIBs and SIBs, due to its higher capacity, exceptional rate capability, longer cycle life, and a Coulombic efficiency exceeding 99 %.

In-situ activated arsenic-molybdenum dual-prodrug nanocomplexes for glutathione-depletion enhanced photothermal/chemotherapy against triple-negative breast cancer

Arsenic trioxide, a traditional chemotherapeutic agent, has limitations in clinical application due to its nonspecific delivery and severe systemic toxicity. To address this challenge, we have capitalized on the promising potential of molybdenum-based materials for tumor diagnosis and treatment. We developed a novel multifunctional arsenic-molybdenum dual-prodrug nanocomposite delivery system (AsMo-NCM) by integrating arsenic compounds with molybdenum compounds. This system leverages elevated glutathione (GSH) levels within tumors for specific activation. Within the tumor microenvironment, the system converts Mo(VI) to the more active Mo(V), enabling combined photothermal therapy and photoacoustic imaging for comprehensive diagnosis and treatment. Furthermore, low-toxicity arsenic(V) is converted into highly toxic trivalent arsenic within the high-GSH tumor microenvironment, thereby enhancing tumor cell apoptosis, reducing toxicity to normal tissues, and synergistically improving treatment outcomes. In addition, AsMo-NCM can be biodegraded and rapidly excreted, reducing concerns about their long-term presence and possible toxic effects. The combination of these approaches maximizes GSH depletion, thereby enhancing the synergistic photothermal/chemotherapy effect of AsMo-NCM for precise and effective tumor treatment, thus offering promising prospects for cancer therapy.

PLGA Nanoparticles Formulations Loaded With Antibiotics Induce Sustained and Controlled Antibiotics Release for Prolonged Antibacterial Action Against MRSA, and Pseudomonas aeruginosa FRD1.

The purpose of the present study was to create resorbable nanoparticles (NPs) using poly(lactic-co-glycolic acid) (PLGA) to develop novel antibacterial therapeutics for the treatment of chronic wound infections that are susceptible to recurrent infections. By first performing a release study, it was possible to predict the behavior of the different PLGA NP formulations and assess the efficacy of the nanocomposite drug delivery system. These PLGA NP formulations consisted of varying ratios of PLGA without polyvinyl alcohol (PVA) and PLGA with PVA (PLGA-PVA) (i.e., 25:75[PLGA25], 50:50[PLGA50], and 75:25[PLGA75]). Then, different antibiotics (i.e., ciprofloxacin and gentamicin) were incorporated into the PLGA NP formulations to test the antibacterial efficacy of these antimicrobial NPs against different pathogens (i.e., methicillin-resistant Staphylococcus aureus USA300 [MRSA], Pseudomonas aeruginosa FRD1, and Acinetobacter baumannii BAA1605). Of particular interest was testing against the MRSA strain USA300 and the P. aeruginosa strain FRD1. This was possible by measuring the zone of inhibition. A 3-day period was used to monitor the antibacterial efficacy of the different PLGA NP formulations (i.e., PLGA25, PLGA50, and a 1:1 combination of PLGA25:PLGA50) against A. baumannii BAA1605, MRSA, and P aeruginosa FRD1. Throughout the study, A. baumannii was a negative control and was resistant to all the PLGA NP formulations loaded with ciprofloxacin and gentamicin. At the end of the 3-day period, the PLGA and PLGA50 ciprofloxacin-loaded formulations produced zones of inhibition of 27 mm and 23 mm, respectively, against P. aeruginosa FRD1. This indicated that P. aeruginosa FRD1 was susceptible to both formulations. The mixed formulations with equal parts PLGA25:PLGA50 loaded with ciprofloxacin produced a zone of inhibition (i.e., 25 mm). This again indicated that P. aeruginosa FRD1 was susceptible to ciprofloxacin. The formulations tested against MRSA showed that only gentamicin-loaded formulations produced intermediate results, and that ciprofloxacin-loaded formulations were ineffective. The PLGA25 and the PLGA50 NP formulations loaded with gentamicin both produced zones of inhibition of 13 mm. This indicated that MRSA was intermediate to both the formulations. The PLGA25:PLGA50 loaded with gentamicin produced a zone of inhibition of 14 mm, which again showed that MRSA was intermediate to this formulation. Overall, these PLGA NP formulations showed the sustained antibacterial potential of a burst release, followed by a sustained release of antibiotics from antibiotics loaded PLGA NPs in a controlled manner. In the future, this can help prevent the emergence of recurrent infections in the treatment of chronic wounds and reduce the number of medical dressing changes.

Unveiling the impact of percolation phenomenon on the microstructure of polymer nanocomposites based on the combination of scaling and percolation theories

AbstractIn this study, a model was proposed to interpret the tensile strength of the nanocomposite systems based on the percolation and scaling theories. Using the Excluded Volumes method made it possible to characterize the reaction mechanism of the system by discretizing all sections of the system in the best way possible. Accordingly, the system was divided into two sections A and B, consisting of either fully dispersed, aggregated, or agglomerated nanoparticles using a percolation parameter (F). The stress concentration factor was introduced to the model based on the available surface area determining the share of each section in affecting the tensile strength of the system. A validation procedure was performed to verify the obtained results using the experimental results of our recent work for a High‐density polyethylene nanocomposite system containing 0.5, 0.75, and 2 wt% of the surface‐modified silica nanoparticles. The investigations indicate the capability of the proposed model to interpret the physical/mechanical characteristics of the nanocomposite systems. It was found that despite the negative impact of the agglomeration on the tensile strength of the system, the aggregation phenomenon enhanced the tensile strength due to the formation of strong networks in its structure.Highlights Interpreting the tensile strength of nanocomposites via excluded volume theory. Dividing the impacts of dispersed and clustered nanoparticles. Discretizing the effects of aggregation and agglomeration on final properties.

Novel ternary nanocomposite (TiO2@Fe3O4-chitosan) system for nitrate removal from water: an adsorption cum photocatalytic approach.

Nitrate pollution of water emerging from various anthropogenic activities has become a major environmental concern because of its deleterious effects on natural water resources. The present work deals with the synthesis of the ternary nanocomposite based on chitosan, iron oxide (Fe3O4), and titanium dioxide (TiO2) and its application for the removal of nitrates from model-contaminated water. Fe3O4 derived through a coprecipitation method was incorporated into the chitosan matrix which was fabricated in the form of beads. The wet gel beads were then successfully coated with sol-gel-derived silver-doped titanium dioxide sol followed by drying under suitable conditions to get the functional nanocomposite beads. The synthesized functional materials were further characterized for their structural, morphological, and textural features using X-ray diffraction analysis, physical property measurement (PPMS), Fourier transform infrared (FTIR) analysis, UV visible spectroscopy analysis (UV-vis), BET surface area analysis (BET), field emission scanning electron microscopic (FESEM), and transmission electron microscopy (TEM) analysis. The ternary nanocomposites were further used for the removal of nitrates via adsorption cum photocatalytic reduction technique from the model contaminated water when subjected to an adsorption study under dark conditions and photocatalytic study under UV/visible/sunlight for a definite time. Fe3O4 in the nanocomposite provides enhanced adsorption features whereas the functional coating of titanium dioxide aids in the removal of nitrates through the photocatalytic reduction technique. The functional beads containing 3% Fe3O4 in the wet gel form (CTA-F3) have excellent nitrate removal efficiency of ~ 97% via adsorption cum solar photocatalysis towards the removal of nitrate ions from 50ppm nitrate solution, whereas the dried nanocomposite beads have got a nitrate removal efficiency of ~ 68% in 1h from 100ppm nitrate solution. Continuous flow adsorption cum photocatalytic study was performed further using the oven-dried functional beads in which flow rate and bed height were varied while maintaining the concentration of feed solution as constant. A nitrate removal efficiency of 65% and an adsorption capacity of 4.1 mgg-1 were obtained for the CTA-F3 beads in the continuous flow adsorption cum photocatalysis experiment for up to 5h when using an inlet concentration of 100ppm, bed height 12cm, and flow rate 5.0mlmin-1. A representative fixed-bed column adsorption experiment conducted using CTA-F3 beads for the treatment of a real groundwater sample shows reasonable results for nitrate removal (71.7% efficiency) along with a significant removal rate for the other anions as well. Thus, the novel adsorbent/photocatalyst developed is suitable for the removal of nitrates from water due to the synergistic effect between Fe3O4, chitosan, and titanium dioxide.

In-situ forming Cu-based metal-organic framework in the presence of chitosan-Fe3O4 nanohybrids: A pH-sensitive carrier for controlled release of doxorubicin

In recent years, stimuli-responsive drug delivery systems based on pH, particularly those developed using bio-derived nanocomposite systems, have gained significant attention. In this work, a novel magnetic carrier was designed based on biopolymeric chitosan and metal-organic framework (MOF) for pH-controlling the release of anticancer drugs. To end this, an in-situ green method was performed to form Cu-based MOF in the presence of a magnetic polysaccharide synthesized by precipitation method toward the construction of CS/Fe3O4/Cu-MOF nanocomposite. The nanocomposite was immersed in an aqueous solution of a model anticancer drug, doxorubicin (DOX), and a higher loading capacity (90.1 ± 0.5 %) was achieved. The in-vitro drug release study showed low release rates in simulated physiological environments (pH 7.4, 37 °C, lower than about 20 %), but higher release rates in tumor tissue conditions (pH 4.5, 41 °C, higher than about 60 %) over 96 h, allowing for sustained and extended delivery of DOX. Additionally, the MTT assay demonstrated that the blank and DOX-loaded CS/Fe3O4/Cu-MOF had good cytocompatibility (over 80 % cell viability) and considerable cytotoxicity (lower than 40 % at 16 μg/mL) toward breast cancer (MCF-7) cell line, respectively. These results indicated that the synthesized nanocomposite with suitable pH-sensitivity has potential as a targeted anticancer agent.

Self-Assembled TiN-Metal Nanocomposites Integrated on Flexible Mica Substrates towards Flexible Devices.

The integration of nanocomposite thin films with combined multifunctionalities on flexible substrates is desired for flexible device design and applications. For example, combined plasmonic and magnetic properties could lead to unique optical switchable magnetic devices and sensors. In this work, a multiphase TiN-Au-Ni nanocomposite system with core-shell-like Au-Ni nanopillars embedded in a TiN matrix has been demonstrated on flexible mica substrates. The three-phase nanocomposite film has been compared with its single metal nanocomposite counterparts, i.e., TiN-Au and TiN-Ni. Magnetic measurement results suggest that both TiN-Au-Ni/mica and TiN-Ni/mica present room-temperature ferromagnetic property. Tunable plasmonic property has been achieved by varying the metallic component of the nanocomposite films. The cyclic bending test was performed to verify the property reliability of the flexible nanocomposite thin films upon bending. This work opens a new path for integrating complex nitride-based nanocomposite designs on mica towards multifunctional flexible nanodevice applications.

A new investigation on graphene-reinforced 304L nanocomposite made by additive manufacturing process: Microstructure and tribology study

In this study, selective laser melting (SLM), as an additive manufacturing method, was applied to produce graphene/304L nanocomposites with various graphene particle sizes and contents. The effect of the graphene particle size (1 μm and 50 nm) and volume fraction on the microstructure behaviors, constitutional phases, mechanical performance, and wear characteristics of the SLM-processed nanocomposite specimens was studied. It was concluded that the reinforcing particle content and size play a remarkable impact on the densification features and the densification level improvs when the fine starting reinforcing particles are used, due to the development of the reinforcement–matrix wettability. In addition, the microstructure refinement and increased hardness values occurred in the SLM-processed nanocomposite system with the addition of reinforcing particles (both sizes). The wear examination indicated that the coefficient of friction (COF), wear rate, and mass loss decreased due to the reinforcement prominent effect, namely grain refinement and grain-boundary strengthening. According to surface topography analysis, the depth of the groove in the processed sample made by fine graphene reinforcement is lower than the other sample.