Incorporation Of Nanomaterials Research Articles

Nano-Biotechnology for Bacteria Identification and Potent Anti-bacterial Properties: A Review of Current State of the Art.

Sepsis is a critical disease caused by the abrupt increase of bacteria in human blood, which subsequently causes a cytokine storm. Early identification of bacteria is critical to treating a patient with proper antibiotics to avoid sepsis. However, conventional culture-based identification takes a long time. Polymerase chain reaction (PCR) is not so successful because of the complexity and similarity in the genome sequence of some bacterial species, making it difficult to design primers and thus less suitable for rapid bacterial identification. To address these issues, several new technologies have been developed. Recent advances in nanotechnology have shown great potential for fast and accurate bacterial identification. The most promising strategy in nanotechnology involves the use of nanoparticles, which has led to the advancement of highly specific and sensitive biosensors capable of detecting and identifying bacteria even at low concentrations in very little time. The primary drawback of conventional antibiotics is the potential for antimicrobial resistance, which can lead to the development of superbacteria, making them difficult to treat. The incorporation of diverse nanomaterials and designs of nanomaterials has been utilized to kill bacteria efficiently. Nanomaterials with distinct physicochemical properties, such as optical and magnetic properties, including plasmonic and magnetic nanoparticles, have been extensively studied for their potential to efficiently kill bacteria. In this review, we are emphasizing the recent advances in nano-biotechnologies for bacterial identification and anti-bacterial properties. The basic principles of new technologies, as well as their future challenges, have been discussed.

Multiple approaches of band engineering and mass fluctuation of solution-processed n-type Re-doped MoS2 nanosheets for enhanced thermoelectric power factor

The thermoelectric (TE) performance of Molybdenum disulpide (MoS2) can be improved by the incorporation of nanomaterials. MoS2 has been reported as promising thermoelectric materials due to their large bandgap and low thermal conductivity. In the present work, n-type MoS2 was successfully synthesized by facile hydrothermal route with an excellent thermoelectric performance by introducing rhenium (Re) dopant. The structural and morphological analyses confirmed the incorporation of Re into Mo (Molybdenum) lattice. The thermoelectric results showed that both the electrical conductivity (σ) and Seebeck coefficient (S) has been increased with the increase in Re content (2.5, 5, 7.5 and 10 at%) and temperature (303 K to 700 K), while the thermal conductivity (κ) was low. Doping with Re on MoS2 enhances the electrical conductivity through band engineering, improving carrier concentration and shifting the Fermi level to the conduction band. Introducing a heavy atomic element can reduce the total thermal conductivity by facilitating mass fluctuation. The maximum Seebeck coefficient was obtained as −100 μVK−1 at 500 K for Re 5 at% sample, which is 3.7 times greater than undoped MoS2. In addition, introducing electrons through Re doping induced bipolar conduction. These enhancements have increased the power factor of 8 μWm-1K−2 at 650 K.

Incorporation of thermally induced shaped and phases of manganese oxide nanoparticles into zein/PVA fiber blends

Incorporation of nanomaterials into polymers and their blend provide additional advantages to their use and structural support. Metals such as Ag, Cu, Ti, and Fe are often reported in their metallic or their oxide forms for applications in microbiological, water treatment, and biomedical fields. The integration of metal oxide nanoparticles into polymer fiber blends overcomes the mechanical instability and compatibility challenges of nanomaterials. Manganese-based oxides provide good stability and optical properties in their nanoscale useful in polymeric composite or fiber materials enhancement. MnO2 and Mn2O3 nanoparticles were synthesized at different calcination temperatures using the co-precipitation method and characterized a microscopic technique TEM, and TGA. TEM images and the XRD patterns confirmed that the manganese oxide nanoparticle were spheres and rod-shaped with corresponding cryptomelane and orthorhombic crystalline phases. Mn2O3 nanoparticles were successfully integrated into zein/PVA (80/20) fiber blends. SEM images confirmed that the inclusion of the nanoparticles into zein/PVA solutions increased the conductivity of the solutions which led to an improved morphology and increased surface area to volume ratio. XRD patterns and TGA showed that the incorporated nanoparticles were below the detection limit, therefore there was no significant change observed. Therefore, all characterization techniques illustrated that the effect of concentration significantly enhanced the morphology of the fiber blends.

Chitosan Hydrogels for Water Purification Applications.

Chitosan-based hydrogels have gained significant attention for their potential applications in water treatment and purification due to their remarkable properties such as bioavailability, biocompatibility, biodegradability, environmental friendliness, high pollutants adsorption capacity, and water adsorption capacity. This article comprehensively reviews recent advances in chitosan-based hydrogel materials for water purification applications. The synthesis methods, structural properties, and water purification performance of chitosan-based hydrogels are critically analyzed. The incorporation of various nanomaterials into chitosan-based hydrogels, such as nanoparticles, graphene, and metal-organic frameworks, has been explored to enhance their performance. The mechanisms of water purification, including adsorption, filtration, and antimicrobial activity, are also discussed in detail. The potential of chitosan-based hydrogels for the removal of pollutants, such as heavy metals, organic contaminants, and microorganisms, from water sources is highlighted. Moreover, the challenges and future perspectives of chitosan-based hydrogels in water treatment and water purification applications are also illustrated. Overall, this article provides valuable insights into the current state of the art regarding chitosan-based hydrogels for water purification applications and highlights their potential for addressing global water pollution challenges.

Mechanistic Elucidation of Nanomaterial-Enhanced First-Generation Biosensors Using Probe Voltammetry of an Enzymatic Reaction.

The incorporation of nanomaterials (NMs) into biosensing schemes is a well-established strategy for gaining signal enhancement. With electrochemical biosensors, the enhanced performance achieved from using NMs is often attributed to the specific physical properties of the chosen nanocomponents, such as their high electronic conductivity, size-dependent functionality, and/or higher effective surface-to-volume ratios. First generation amperometric biosensing schemes, typically utilizing NMs in conjunction with immobilized enzyme and semi-permeable membranes, can possess complex sensing mechanisms that are difficult to study and challenging to understand beyond the observable signal enhancement. This study shows the use of an enzymatic reaction between xanthine (XAN) and xanthine oxidase (XOx), involving multiple electroactive species, as an electrochemical redox probe tool for ascertaining mechanistic information at and within the modified electrodes used as biosensors. Redox probing using components of this enzymatic reaction are demonstrated on two oft-employed biosensing approaches and commonly used NMs for modified electrodes: gold nanoparticle doped films and carbon nanotube interfaces. In both situations, the XAN metabolism voltammetry allows for a greater understanding of the functionality of the semipermeable membranes, the role of the NMs, and how the interplay between the two components creates signal enhancement.

Wood sawdust waste-derived nano-cellulose as a versatile reinforcing agent for nano silica cement composites: a systematic study on its characterization and performance

The development of sustainable construction materials is a pressing concern for researchers worldwide, as the cement industry is a major contributor to environmental degradation. The incorporation of nano-materials with cement composites has emerged as a promising solution to sustainable materials production. In this study, the effect of the addition of nano cellulose produced from wood sawdust waste on the performance of cement-based nano-silica composite was investigated. The nano-materials were incorporated at low concentrations and in gel form to eliminate the need for any advanced dispersion techniques. The results indicated that the addition of even low concentrations of nano cellulose significantly enhanced the compactness and mechanical properties of the cement matrix. The crack propagation was observed to be arrested with better adherence to the cement hydration product, which resulted from the presence of nano-silica. The nano cellulose fibers were found to bridge the calcium silicate hydrate products, arresting the propagation of cracks at their initial condition. The high pozzolanic reactivity of nano-silica ensured a minimal amount of calcium hydroxide, which is a significant contributor to the carbon footprint of cement production. Overall, the findings of this study suggest that the incorporation of nano cellulose from wood sawdust waste with cement-based nano-silica composite can lead to the development of sustainable and high-performance building materials with improved mechanical properties and reduced environmental impact.

Effects of MOFs size and functional group on the pore structure and performance of thin-film nanocomposite membranes

Incorporation of nanomaterials into the selective layer during the interfacial polymerization process was an effective way to improve the perm-selectivity of the membranes. In this study, the piperazine enriched templates assisted interfacial polymerization method was proposed to enhance the salts rejection of thin-film nanocomposite (TFN) membranes. The mono-dispersed UiO-66 type MOFs with high amine adsorption ability were utilized as templates to increase the reaction region and promote the participation of piperazine (PIP) during the interfacial polymerization reaction, resulting in a denser polyamide (PA) layer with weaker surface electronegativity and higher nitrogen-containing group contents. The TFN membranes prepared with 236 nm UiO-66-OH and PIP concentration of 0.35 w/v% exhibited smaller mean pore size (0.636 nm) and reduced surface zeta potential (−26.0 mV) compared to the pristine TFC membranes (0.667 nm and −31.1 mV). Consequently, the rejection of 10 mM MgCl2, MgSO4 and Na2SO4 was increased from 44.7%, 97.7% and 98.3% to 84.3%, 99.2% and 99.5%, respectively, while the pure water flux was slightly decreased from 53.5 L m−1 h−1 to 37.4 L m−1 h−1 at 0.3 MPa. In addition, the size and functional group of the MOFs were found to have significant impacts on the pore structure and performance of the TFN membranes. The increasing of reaction region with relatively large MOFs and higher absorption ability were beneficial to obtain a thicker PA layer, while strong interaction between MOFs and PA oligomers was unfavorable for PA chain packing. Therefore, the TFN membranes prepared with UiO-66-NO2 exhibited a much narrow size distribution and high rejection to all salts, whether by divalent cationic salt or divalent anion salts, i.e., MgCl2 of 95.5%, MgSO4 of 98.9% and Na2SO4 of 99.1%, and the pure water flux was 28.6 L m−1 h−1 at 0.3 MPa. These results illustrated the influences of MOFs size and functional group on the interfacial polymerization process, which was crucial for the TFN membranes preparation.

Strength predictive models of cementitious matrix by hybrid intrusion of nano and micro silica: Hyper-tuning with ensemble approaches

The incorporation of nanomaterials (NMs) in concrete will produce the utmost properties. Nevertheless, investigational work takes a great deal of time with efforts to measure the strength of concrete. Thus, the process of estimating the properties of cement paste can be accelerated by employing soft machine learning (SML) techniques. Individual machine learning approaches (MLAs) like random forest (RF), decision tree (DT), and support vector machine (SVM) were utilized. These individual MLAs models then ensemble with two approaches namely bagging and boosting. The outcome of the model depicts a robust performance by showing significant correlations (R2) as compared to individual MLAs. Data points with 205 having contribution factors (e.g., curing time (days), water to binder (w/b), micro-silica (%), and nano-silica (%) were used as input parameters, and compressive strength as output for MLAs modeling. To ensure that each model is as accurate as possible, cross-validation with K-folding and statistical error analysis (i.e., MAE, MAE, and RMSE) were utilized. Thus, interpretable approaches with AdaBoost give a strong correlation of R2 ranging from 0.85 to 0.90 respectively with fewer errors. Out of which DT with ensemble Adaboost and RF give a robust performance. Moreover, the results of the cross-validation show that the response was accurate, with fewer errors. Therefore, the ensemble model represents a robust correlation. Therefore, its usage with individual ML would enhance the model's performance. In addition, the graphical user interface (GUI) is created by training a model that can predict the values of the desired outputs when the necessary input parameters are provided. It simplifies the procedure and provides a handy tool for employing the model's capabilities in the civil engineering domain.

Cancer phototherapy with nano-bacteria biohybrids.

The utilization of light for therapeutic interventions, also known as phototherapy, has been extensively employed in the treatment of a wide range of illnesses, including cancer. Despite the benefits of its non-invasive nature, phototherapy still faces challenges pertaining to the delivery of phototherapeutic agents, phototoxicity, and light delivery. The incorporation of nanomaterials and bacteria in phototherapy has emerged as a promising approach that leverages the unique properties of each component. The resulting nano-bacteria biohybrids exhibit enhanced therapeutic efficacy when compared to either component individually. In this review, we summarize and discuss the various strategies for assembling nano-bacteria biohybrids and their applications in phototherapy. We provide a comprehensive overview of the properties and functionalities of nanomaterials and cells in the biohybrids. Notably, we highlight the roles of bacteria beyond their function as drug vehicles, particularly their capacity to produce bioactive molecules. Despite being in its early stage, the integration of photoelectric nanomaterials and genetically engineered bacteria holds promise as an effective biosystem for antitumor phototherapy. The utilization of nano-bacteria biohybrids in phototherapy is a promising avenue for future investigation, with the potential to enhance treatment outcomes for cancer patients.

An Elucidative Review of the Nanomaterial Effect on the Durability and Calcium-Silicate-Hydrate (C-S-H) Gel Development of Concrete.

Concrete as a building material is susceptible to degradation by environmental threats such as thermal diffusion, acid and sulphate infiltration, and chloride penetration. Hence, the inclusion of nanomaterials in concrete has a positive effect in terms of promoting its mechanical strength and durability performance, as well as resulting in energy savings due to reduced cement consumption in concrete production. This review article discussed the novel advances in research regarding C-S-H gel promotion and concrete durability improvement using nanomaterials. Basically, this review deals with topics relevant to the influence of nanomaterials on concrete's resistance to heat, acid, sulphate, chlorides, and wear deterioration, as well as the impact on concrete microstructure and chemical bonding. The significance of this review is a critical discussion on the cementation mechanism of nanoparticles in enhancing durability properties owing to their nanofiller effect, pozzolanic reactivity, and nucleation effect. The utilization of nanoparticles enhanced the hydrolysis of cement, leading to a rise in the production of C-S-H gel. Consequently, this improvement in concrete microstructure led to a reduction in the number of capillary pores and pore connectivity, thereby improving the concrete's water resistance. Microstructural and chemical evidence obtained using SEM and XRD indicated that nanomaterials facilitated the formation of cement gel either by reacting pozzolanically with portlandite to generate more C-S-H gel or by functioning as nucleation sites. Due to an increased rate of C-S-H gel formation, concrete enhanced with nanoparticles exhibited greater durability against heat damage, external attack by acids and sulphates, chloride diffusion, and surface abrasion. The durability improvement following nanomaterial incorporation into concrete can be summarised as enhanced residual mechanical strength, reduced concrete mass loss, reduced diffusion coefficients for thermal and chloride, improved performance against sulphates and acid attack, and increased surface resistance to abrasion.

Recent progress in Epoxy Nanocomposites: Corrosion, structural, flame retardancy and applications — A comprehensive review

AbstractIn the past few years, epoxy resins utilization has gained much significant recognition from researchers worldwide as a result of its advantages in different sectors such as automotive, aerospace, electronic systems, constructions, and other related fields because of its outstanding mechanical performance, corrosion protection, and dielectric properties. The nanomaterials incorporation into the matrix has been duly examined to be the most productive route to enhance polymer composite's mechanical properties. Despite that, the inherent brittleness, relatively low fracture toughness, cross‐linking ability, poor electrical, and thermal properties of epoxy render it weak to growth and initiation of cracks, limiting its utilization in state‐of‐the‐art structural applications. Especially, epoxy is flammable while releasing a considerable amount of gases and smoke, thus, extending a potential risk to lives. Consequently, several nanofiller materials like graphene (Gr), transition metal dichalcogenides, MXene, and hexagonal boron nitride (h‐BN) produce extensive chances to equip multi‐functional characteristics and then reinforce the epoxy resins for the state‐of‐the‐art application. With this current review, the present literature investigation of epoxy filled with nano‐sized material has been examined thoroughly. Current advances in the approach of integrating nanosized materials in the epoxy matrices have been also introduced. Most significantly, anti‐corrosion, mechanical, and flame‐retardant properties of nanomaterials reinforced epoxy nanocomposites have also been reviewed in particular. Ultimately, the present statuses of the field in addition to the future approach have been considered concerning the usefulness of numerous nanofillers toward reinforcement of epoxy in construction and building materials. The expectation in this extensive review could produce a valuable reference, ingenuity, and guidance for researchers in this area of study.

Chitosan Biopolymer and Its Nanocomposites: Emerging Material as Adsorbent in Wastewater Treatment

Water pollution is a global issue because of potentially lethal toxins. Polymeric nanomaterials are making their way into water treatment processes and are being utilized to efficiently remove a variety of pollutants. Polymeric nanomaterials are a popular option for a solution because they have a high adsorption capacity and a high surface charge. Nanocomposites have recently come to the attention of those working in the field of water treatment in order to more effectively remove contaminants. Polymeric composites are based on biopolymers and are being developed. These all quickly reached the industrial standards because of their low impact on the natural world. Chitosan is one of the biopolymers that are used extensively. Moreover, it is one of the most highly preferred biopolymers. It is simple to scale up and is readily available. The incorporation of nanomaterials into the biopolymer enables better control over the shape, size, and morphology of the particle, as well as an increase in the efficiency with which contaminants are removed. This is an excellent review that examines recent developments in the formation of chitosan-based polymeric nanocomposites and their performance in removing various contaminants including heavy metals, dyes, pesticides, pharmaceutical waste, and radionuclides from water.

Effect of nanomaterials (carbon nanotubes, nano-silica, graphene oxide) on bond behavior between concrete and reinforcing bars

The purposes of this study are (i) to evaluate the mechanical properties of triple hybrid-reinforced concrete mixed with carbon nanotubes, nano-silica, and graphene oxide and (ii) to determine the effect of these properties on the bond strength. First of all, compressive strength and splitting tensile strength tests were performed to evaluate the mechanical properties of triple hybrid-reinforced concrete. It has been observed that the flexural strength of concrete increases and the Poisson's ratio and volumetric strain decrease with the incorporation of nano-materials, and the effect is most pronounced when graphene oxide is added. Next, pull-out tests were conducted using a total of 21 specimens of triple hybrid-reinforced concrete. Similarly to the material test results, the bond performance of triple hybrid-reinforced concrete was found to be the highest, which can be attributed to the minimal volumetric deformation of the concrete. By this, the bond strength of Triple hybrid-reinforced concrete was evaluated, taking into account the mechanical properties. When considering Poisson's ratio and flexural strength, it was possible to predict them relatively accurately. In future research, it will be necessary to analyze additional mechanical properties such as friction coefficient and shrinkage strain of nano concrete to incorporate them into the bond strength model.

Laponite-Based Nanocomposite Hydrogels for Drug Delivery Applications.

Hydrogels are widely used for therapeutic delivery applications due to their biocompatibility, biodegradability, and ability to control release kinetics by tuning swelling and mechanical properties. However, their clinical utility is hampered by unfavorable pharmacokinetic properties, including high initial burst release and difficulty in achieving prolonged release, especially for small molecules (<500 Da). The incorporation of nanomaterials within hydrogels has emerged as viable option as a method to trap therapeutics within the hydrogel and sustain release kinetics. Specifically, two-dimensional nanosilicate particles offer a plethora of beneficial characteristics, including dually charged surfaces, degradability, and enhanced mechanical properties within hydrogels. The nanosilicate-hydrogel composite system offers benefits not obtainable by just one component, highlighting the need for detail characterization of these nanocomposite hydrogels. This review focuses on Laponite, a disc-shaped nanosilicate with diameter of 30 nm and thickness of 1 nm. The benefits of using Laponite within hydrogels are explored, as well as examples of Laponite-hydrogel composites currently being investigated for their ability to prolong the release of small molecules and macromolecules such as proteins. Future work will further characterize the interplay between nanosilicates, hydrogel polymer, and encapsulated therapeutics, and how each of these components affect release kinetics and mechanical properties.

The Reinforcing Effect of Nano-Modified Epoxy Resin on the Failure Behavior of FRP-Plated RC Structures

The ability to manipulate concrete-based and composite materials at the nanoscale represents an innovative approach to improving their mechanical properties and designing high-performance building structures. In this context, a numerical investigation of the reinforcing effect of nano-modified epoxy resin on the structural response of fiber-reinforced polymer (FRP)-plated reinforced concrete (RC) components has been proposed. In detail, an integrated model, based on a cohesive crack approach, is employed in combination with a bond–slip model to perform a failure analysis of strengthened structures. In particular, the proposed model consists of cohesive elements located on the physical interface between concrete and FRP systems equipped with an appropriate bond–slip law able to describe the reinforcing effect induced by the incorporation of nanomaterials in the bonding epoxy resin. Preliminary analyses, performed on reinforced concrete prisms, highlight an increment of 28% in the bond strength between concrete and the FRP system, offered by the nanomaterials embedded in the adhesive layer with respect to the standard one. Moreover, the numerically predicted structural response of a nano-modified FRP-plated beam shows an increment of around 5.5% in the failure load and a reduction in the slip between concrete and the FRP plate of around 76%, with respect to the reinforced beam without nanomaterial incorporation. Finally, the good agreement with experimental results, taken from the literature, highlights the excellent capability of the proposed model to simulate the mechanical behavior of such types of reinforced structures, emphasizing the beneficial effects of the nano-enhanced epoxy resin on the bond strength between concrete and FRP systems.

Fouling-resistant surface modification of forward osmosis membranes using MoS2-Ag nanofillers

The mitigation of organic fouling is a main challenge for forward osmosis (FO) technology. In order to enhance the fouling resistance and desalination efficiency of the FO membrane, various studies have suggested the incorporation of nanomaterials into thin-film composite (TFC) membranes, which are defined as thin-film nanocomposite (TFN) membranes. In this study, we fabricated MoS2-Ag nanofillers by photochemical deposition method and incorporated them into TFC membranes for FO water treatment. After incorporation of MoS2-Ag nanofillers into TFC membranes, we could observe significant change in the surface of membranes. Especially, active layer surface of TFN membrane was smoothened, which was represented by decrease of roughness from 40.09 ± 1.39 nm of TFC membrane to 15.53 ± 0.17 nm of TFN membrane. Furthermore, according to the hydrophilic surface modification, contact angle of membranes was also decreased from 79.0 ± 2.0° of TFC membrane to 52.2 ± 0.7° of TFN membrane. The surface modification of the TFN membrane resulted in improvement of desalination capacity in terms of 35.2% improved water flux. Finally, the resistance to alginate fouling of TFN membrane was realized and it exhibited almost 4 times lower water flux loss than TFC membrane. This study presents that photochemically synthesized nanofillers could modify the surface of TFN membrane, therefore, this technique can be a feasible approach to future membrane-based technologies.

Flowers Like α-MoO3/CNTs/PANI Nanocomposites as Anode Materials for High-Performance Lithium Storage.

Lithium-ion batteries (LIBs) have been explored to meet the current energy demands; however, the development of satisfactory anode materials is a bottleneck for the enhancement of the electrochemical performance of LIBs. Molybdenum trioxide (MoO3) is a promising anode material for lithium-ion batteries due to its high theoretical capacity of 1117 mAhg-1 along with low toxicity and cost; however, it suffers from low conductivity and volume expansion, which limits its implementation as the anode. These problems can be overcome by adopting several strategies such as carbon nanomaterial incorporation and polyaniline (PANI) coating. Co-precipitation method was used to synthesize α-MoO3, and multi-walled CNTs (MWCNTs) were introduced into the active material. Moreover, these materials were uniformly coated with PANI using in situ chemical polymerization. The electrochemical performance was evaluated by galvanostatic charge/discharge, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). XRD analysis revealed the presence of orthorhombic crystal phase in all the synthesized samples. MWCNTs enhanced the conductivity of the active material, reduced volume changes and increased contact area. MoO3-(CNT)12% exhibited high discharge capacities of 1382 mAhg-1 and 961 mAhg-1 at current densities of 50 mAg-1 and 100 mAg-1, respectively. Moreover, PANI coating enhanced cyclic stability, prevented side reactions and increased electronic/ionic transport. The good capacities due to MWCNTS and the good cyclic stability due to PANI make these materials appropriate for application as the anode in LIBs.

Effects of recycled sand and nanomaterials on ultra-high performance concrete: Workability, compressive strength and microstructure

The use of recycled sand (RS) from construction and demolition (C&D) waste to produce ultra-high performance concrete (UHPC) is a promising but challenging methodology for low-carbon technology innovation. In this study, an economic and effective approach to optimize the performance of recycled sand UHPC (RSUHPC) is developed. An experimental study was conducted to investigate the effects of RS and nanomaterials on the physical properties, mechanical behaivour, and microstructure of UHPC. The results show that the compressive performance of RSUHPC decreased with increasing RS content, but the addition of nanomaterials can significantly counteract this negative impact. Nanomaterial incorporation in the mix had an impact on the fresh and hardened properties and the microstructure of the reaction products. Based on the synthetic consideration of the performance improvement and economic cost, a content of 25% RS and 1% NS is optimal for RSUHPC. After modification with 1% NS, the compressive strength of RSUHPC at 28 days increased by 14%, reaching 152 MPa.

Nanocomposite substrate-supported nanofiltration membrane for efficient treatment of rare earth wastewater

The incorporation of nanomaterials into the selective layer of nanofiltration membranes can effectively enhance membrane performance. However, the agglomeration of nanoparticles inevitably leads to defects in the membrane PA layer. To address this issue, this paper reports a novel nanocomposite substrate-supported thin-film composite (TFC) nanofiltration membrane with good stability and excellent separation performance. Inorganic two-dimensional O–MoS2 nanosheets were embedded into a polysulfone (PSF) substrate by a non-solvent-induced phase transition method. The PSF/O–MoS2 nanocomposite was used as a support for the interfacial polymerization between piperazine and tricarbonyl chloride. The pore morphology of the nanocomposites changed dramatically as the O–MoS2 content increased. With the optimal content of O–MoS2 in substrates was 0.06 wt%, the pore structure of the substrate changed from a larger irregular bubble pore structure to a finger-like pore structure. The nanocomposite matrix-supported TFC membrane exhibited 1.7 times higher water flux and better salt removal compared to the control membrane. Meanwhile, the obtained nanofiltration membranes showed excellent separation performance in treating simulated rare earth wastewater (P507) containing surfactants with a desalination rate of 97.08%. The desalination rate also reached 95% in a 24- h performance test on real rare earth wastewater (50-fold dilution), demonstrating its great potential for industrial applications. This work also highlights that modification of substrates with functional nanomaterials can provide a versatile approach to enhance the separation performance and stability of TFC membranes.

Advances of Mussel-Inspired Nanocomposite Hydrogels in Biomedical Applications.

Hydrogels, with 3D hydrophilic polymer networks and excellent biocompatibilities, have emerged as promising biomaterial candidates to mimic the structure and properties of biological tissues. The incorporation of nanomaterials into a hydrogel matrix can tailor the functions of the nanocomposite hydrogels to meet the requirements for different biomedical applications. However, most nanomaterials show poor dispersion in water, which limits their integration into the hydrophilic hydrogel network. Mussel-inspired chemistry provides a mild and biocompatible approach in material surface engineering due to the high reactivity and universal adhesive property of catechol groups. In order to attract more attention to mussel-inspired nanocomposite hydrogels, and to promote the research work on mussel-inspired nanocomposite hydrogels, we have reviewed the recent advances in the preparation of mussel-inspired nanocomposite hydrogels using a variety of nanomaterials with different forms (nanoparticles, nanorods, nanofibers, nanosheets). We give an overview of each nanomaterial modified or hybridized by catechol or polyphenol groups based on mussel-inspired chemistry, and the performances of the nanocomposite hydrogel after the nanomaterial's incorporation. We also highlight the use of each nanocomposite hydrogel for various biomedical applications, including drug delivery, bioelectronics, wearable/implantable biosensors, tumor therapy, and tissue repair. Finally, the challenges and future research direction in designing mussel-inspired nanocomposite hydrogels are discussed.