Addition Of Nanofillers Research Articles

Retracted: Statistical Analysis on the Mechanical Properties of ATH Nanofiller Addition on the Woven Jute/Polyester Hybrid Composites by the Grey–Taguchi Method

Retracted: Statistical Analysis on the Mechanical Properties of ATH Nanofiller Addition on the Woven Jute/Polyester Hybrid Composites by the Grey–Taguchi Method

Nano‐BN/Nano‐TiO2 and micro Mg(OH)2 loaded hybrid ethylene propylene diene monomer elastomer composites for outdoor high‐voltage insulation application

AbstractThis work deals with the synthesis, characterization of hybrid ethylene propylene diene monomer (EPDM) composites loaded with nano‐boron nitride (nano‐BN)/nano‐titanium dioxide (nano‐TiO2) and micro Mg(OH)2 particles for its suitability towards high‐voltage insulation application. The elastomer samples were prepared by carefully dispersing the micro and nano fillers during the mastication process of EPDM polymer using a two roll mill, followed by vulcanization. The samples were characterized for mechanical, morphological, thermal, and electrical insulation properties. The highest tensile strength among the composite samples was noted for 1 phr nanoparticles loaded samples. Fourier Transform Infrared (FTIR) results show no change in the chemical moiety upon addition of nano‐BN/nano‐TiO2 in EPDM composites. Enhancement in hydrophobicity is observed for 3 phr nano‐TiO2 loaded composites, which shows a maximum static contact angle of 110°. Meanwhile remarkable enhancement in the thermal conductivity and volume resistance of the composites are contributed to the addition of nano‐BN, thereby achieving maximum dielectric breakdown voltage (i.e., ~21 kV/mm for EMB3). Scanning electron microscope images and atomic force microscopy (AFM) topography highlight that low concentration (i.e., 1 phr) based composites have homogeneous dispersion in matrix and excessive nano filler addition deteriorates properties by forming filler aggregates and increasing surface roughness.

Sonochemically tailored Copper Oxide as nanofiller in terpolymer composite gel electrolytes for dye-sensitized solar cells

This article describes the impact of several weight percentages of copper oxide (CuO) as a nanofiller on the structure, morphology, and electrochemical performance of dye-sensitized solar cells (DSSC). CuO-350 was synthesized using a sonochemical method following by calcination at 350 ℃ and was incorporated into the polymer-salt system to develop a polymer composite gel electrolyte (PCGE). The improvement in the amorphous phase and complexation between the constituents were proven via X-ray diffraction, and Fourier transform infrared. However, the thermal stability declines with the addition of CuO-350 nanofillers. It was found that TCuO350–5 exhibited the highest ionic conductivity and apparent diffusion coefficient of triiodide of (3.49±0.01)×10−3 S cm−1 and 1.48 × 10−5 cm2 s−1, respectively. The best-performing sample among PCGE is found to be TCuO350–5, containing 5 wt% of CuO-350 with an efficiency of 7.69% with JSC of 23.47 mA cm−2, VOC of 0.62 V, and fill factor of 52.9%. In addition, it also has the highest charge collection efficiency (87.31%) and longest electron lifetime (1.446 s). TCuO350–5 has achieved the stability of the device with efficiency retained 92% at room temperature and retains 80% efficiency even at 80 ℃.

High discharge energy density in rationally designed graphene oxide@zinc oxide/polymer blend-polyetherimide heterostructured bilayer nanocomposites

The advancement of new dielectric materials exhibiting greater discharge energy density is crucial for current power systems and electronic devices. In this work, various weight percentages of graphene oxide@zinc oxide (GO@ZO) nanofillers were incorporated inside a polymer blend of poly(vinylidene fluoride-hexafluoropropylene)/polyetherimide (P(VDF-HFP)/PEI; shortened as BP) and used as a high dielectric top layer. In contrast, linear-type PEI (L) was used as a bottom insulation layer to achieve a high breakdown strength (Eb) in bilayer nanocomposites. As a result, the 2BP-L composite demonstrated a high discharged energy density of 12.63 J/cm3 at an electric field of 527 MV/m with only 2 wt% GO@ZO nanofillers addition in the top layer. Such a high discharge energy density with minimal nanofiller loading is attributed to the utilization of novel surface-decorated GO@ZO nanofillers and new bilayer-heterostructured linear/ferroelectric-linear polymer. In comparison to its counterparts (i.e., PEI, P(VDF-HFP) and 0BP-L), the 2BP-L nanocomposite showed ∼426.3 %, 92.5 %, and 9.8 % enhancement in discharge energy density, respectively. The discharge rate and stability analysis revealed a significantly higher power density of 0.55 MW/cm3, indicating its high potential to be used as a pulsed power system. Finite element simulation revealed that the effective internal electric field distribution and higher dielectric displacement in 2BP-L resulted in such enhancement over its counterparts. This study presents a new model to maximize the energy storage capability of flexible energy storage devices and advances knowledge of the polarization mechanisms and breakdown of bilayer nanocomposite dielectric materials.

Experimental and numerical studies on the mechanical characteristics of Timoho fiber epoxy composites with nanofiller addition

AbstractThis study is focused on the investigation of the mechanical characteristics of Timoho fiber (TF) epoxy composites with graphene as the filler material, both experimentally and numerically, for high‐velocity impacts. The composites were prepared by the compression molding process with varying wt.% of graphene. An experimental approach was undertaken to study the behavior of the composites under different wt.% of graphene. To validate the results obtained in the experimental approach, numerical studies were conducted. It was observed that there was an enhancement in the mechanical properties with the addition of graphene. For tensile strength, there was an increase of 33.17% when comparing the controlled sample (0% graphene) and the sample with 2% graphene content. Subsequently, there was an increase of 36.48%, 58.02%, and 29.79% when comparing the controlled samples and samples with 2% graphene, respectively, for flexural, impact, and interlaminar shear strength (ILSS). However, it was observed that after the addition of 2 wt.% of graphene, the mechanical strength decreased due to the agglomeration of graphene inside the composite, which was confirmed using the SEM analysis. For the numerical study, ANSYS workbench was employed, and simulation was conducted using finite element analysis (FEA) for the tensile and flexural test. The numerical findings were found to be reasonably close to the experimental values, with variations ranging from a minimum of 2% to a maximum of 15%. In the design of experiments, Taguchi's approach was used to determine the effect of a variety of parameters on the tensile behavior of the TF epoxy composites.Highlights 2 wt.% of graphene was observed to be the optimum concentration of graphene. The decline in mechanical properties was observed at 3 and 4 wt.% of graphene. Agglomeration of graphene filler in the composite was confirmed using SEM. ANOVA showed that wt.% of graphene made the top contribution to tensile strength. The nanographene‐incorporated TF composites can be used for lightweight applications.

Hydrothermal aging of glass fiber epoxy‐carbon nanocomposites and its service life predictions based on tensile strength

AbstractThis paper investigates the hydrothermal aging of pultruded glass‐fiber reinforced epoxy nanocomposite rods with carbon nanofillers. The nanocomposites developed in this study are proposed for the core of high‐tension low‐sag conductors in power transmission. Nanocomposites were fabricated with a nanomodified matrix containing 0.2 wt.% of multi‐walled carbon nanotubes and 0.6 wt.% of graphene nanoplatelets. The epoxy nanocomposites tensile strength and life predictions were determined under different water aging conditions. Objective of the study is to evaluate the water absorption kinetics and its impact on tensile strength, microstructure and to compute the service life under hydrothermal aging by predictive techniques. Nanocomposites were aged in water at 30, 50, and 80°C for a duration of 3000 h, and the microstructure and chemical composition were investigated. Based on Arrhenius's theory, a service life prediction model based on the tensile‐strength of the nanocomposite is established for hydrothermal aging. The results have shown that the addition of carbon nanofillers to the epoxy matrix improves the hydrophobicity and reduces the water diffusion coefficient. Water absorptions of the nanocomposites are observed to follow Fick's law, and its influence on the mechanical properties of the nanocomposite is evident and is more significant in epoxy composites without carbon nanofillers. After 3000 h of immersion at 50 and 80°C, the tensile strength retention is above 85%. The hydrothermal environment accelerates the development of micro‐voids and cracks, which are initially formed and observed to be the primary reason for the degradation in mechanical strength under service conditions, in addition to debonding of the fibers.Highlights Carbon nanocomposites were aged at different temperatures and durations. Service life prediction model established based on Arrhenius's theory. Addition of carbon nanofillers enhances hydrophobicity and reduces water diffusion. Tensile strength retention above 85% after 3000 h of aging. Hydrothermal aging accelerates aging contributing to strength degradation.

Analysis of contact creep behaviour of nanofilled composites

An effective modelling method for analysing the contact creep behaviour of composite materials with different nanofillers was proposed. Considering both the contact and creep material nonlinearities, an augmented Lagrangian algorithm was used to treat the unilateral contact constraints, and a time-hardening creep constitutive equation was adopted to describe the deformation characteristics of the nanocomposites. The constitutive parameters were extracted through a series of linear fittings based on the multiaxial creep theory and creep test curves, and the accuracy of the constitutive equation was validated. The applications of the proposed modelling method were demonstrated using a rope-wheel contact system (RWCS), in which the wheels were made of polystyrene (PS) with carbon black (CB), multi-walled carbon nanotubes (MWCNT), or chemically reduced graphene oxide (CRGO). The results indicated that the addition of nanofillers significantly reduced the creep deformation of the contact zone. The CRGO exhibited a better anti-creep performance than that of CB and MWCNT. Compared with pure PS, the maximum deformation on the contact path of the nanocomposite wheel with 5.0 wt% CRGO sheets at 1500 s and 104 s was reduced by approximately 22 % and 52 %, respectively. The coefficient of friction μ had a strong influence on the contact creep deformation when μ < 0.3. Additionally, the anti-creep capability of the added nanofillers became more evident as the loading time increased. The contact creep deformation of the CRGO composite was less than one-tenth that of the matrix material after 30 d.

Characteristics of nanocomposite film based on elephant foot-yam starch (Amorphophallus paeoniifolius) with different nanocrystalline cellulose concentration

ABSTRACTBionanocomposite film is composed of renewable materials such as polymer with the addition of nanofiller in the form of nanocrystal cellulose (NCC). Biopolymer serves as a matrix, while nanofiller is dispersed to improve the functional properties. NCC is a nanoparticle commonly used in the production of bioplastics, and the addition to nanocomposite film can enhance the mechanical and barrier properties. Therefore, this study aimed to determine the physio-chemical, mechanical, and permeability characteristics of elephant foot-yam starch-based nanocomposite films by adding different concentrations of NCC at 3, 5, and 7 wt.%. The experiment used elephant foot-yam starch, NCC, sorbitol, and carboxymethyl cellulose (CMC) as biopolymer, nanofiller, plasticizer, and stabilizer, respectively. The results showed that the optimum concentration was 7 wt.% NCC, showing tensile strength, elongation, WVTR, and thickness consistent with the Japanese Industrial Standard. NCC dispersion showed favorable water solubility and excellent biodegradability, yielding optimal SEM and FTI-R results. SEM analysis showed a well-dispersed structure, while FTI-R showed sharper spectra in specific functional groups. Moreover, XRD showed several diffraction peaks with strong intensity at 2θ = 17.12°(101̅), 22.75° (002), and 35.0° (040), confirming the presence of NCC in the film matrix. Based on the results, this nanocomposite had great potential to be developed into environmentally friendly packaging.

Biomass fly ash as nanofiller to improve the dielectric properties of low-density polyethylene for possible high-voltage applications

Flexible capacitive energy storage applications require polymer nanocomposites with high dielectric properties, which can be accomplished by addition of inorganic nanofillers to the polymer matrix. Low-density polyethylene (LDPE), known for its good dielectric characteristics and wide use in electrical insulation have been investigated for the desired applications. However, the improvement of its breakdown strength still continues with the use of various nanomaterials employed as nanofillers. In this study, a waste-derived material known as biomass fly ash (BFA) as a nanofiller to improve the dielectric properties of LDPE has been explored. BFA exhibits versatility in its composition with various metal oxides, making it an attractive choice as a nanofiller. The BFA-LDPE sheets were prepared using a conventional solvent mixing and subsequent hot-pressing process, incorporating BFA loadings ranging from 1 % to 4 wt%. The effects of different BFA loadings were carefully examined, and the synthesized nanocomposites were extensively characterized using various characterization methods, such as XRD, SEM, FTIR, TGA and dielectric constant measurements, to investigate the crystallographic properties, morphology, chemical composition, and thermal stability. Among all the nanocomposites, 4 wt%BFA-LDPE exhibited the highest dielectric constant, with a value of 11.58, compared to simple LDPE that had a dielectric constant of 8.33. This improvement is ascribed to the synergistic effects of different inorganic metal oxides (SiO2, MgO, and Fe2O3) present in BFA. The results showed a significant enhancement in dielectric properties, indicating that the waste-derived BFA can be purposefully applied as an effective nanofiller in the LDPE-based composites with even less than 4% loading for electrical insulating applications in future studies.

Mesoscopic Modeling and Experimental Validation of Thermal and Mechanical Properties of Polypropylene Nanocomposites Reinforced By Graphene-Based Fillers.

The development of nanocomposites relies on structure-property relations, which necessitate multiscale modeling approaches. This study presents a modeling framework that exploits mesoscopic models to predict the thermal and mechanical properties of nanocomposites starting from their molecular structure. In detail, mesoscopic models of polypropylene (PP)- and graphene-based nanofillers (graphene (Gr), graphene oxide (GO), and reduced graphene oxide (rGO)) are considered. The newly developed mesoscopic model for the PP/Gr nanocomposite provides mechanistic information on the thermal and mechanical properties at the filler-matrix interface, which can then be exploited to enhance the prediction accuracy of traditional continuum simulations by calibrating the thermal and mechanical properties of the filler-matrix interface. Once validated through a dedicated experimental campaign, this multiscale model demonstrates that with the modest addition of nanofillers (up to 2 wt %), the Young's modulus and thermal conductivity show up to 35 and 25% enhancement, respectively, whereas the Poisson's ratio slightly decreases. Among the different combinations tested, the PP/Gr nanocomposite shows the best mechanical properties, whereas PP/rGO demonstrates the best thermal conductivity. This validated mesoscopic model can contribute to the development of smart materials with enhanced mechanical and thermal properties based on polypropylene, especially for mechanical, energy storage, and sensing applications.

Improved electrochemical performance of bio-derived plasticized starch/ reduced graphene oxide/ molybdenum disulfide ternary nanocomposite for flexible energy storage applications

A ternary nanocomposite of plasticized starch (PS), reduced graphene oxide (rGO), and molybdenum disulfide (MoS2) was prepared via a solution casting process, with MoS2 concentrations ranging from 0.25 to 1.00 wt%. The structural, surface morphological, optical, and electrochemical properties of the nanocomposites were studied. FTIR analysis reveals the formation of new chemical bonds between PS, rGO, and MoS2, indicating strong interactions among them. The XRD analysis showed a reduction in the crystallinity of the nanocomposite from 40 to 21% due to the incorporation of nanofiller. FESEM micrograph showed an increment of the surface roughness due to the incorporation of rGO-MoS2 layers. UV–vis spectroscopy demonstrated a reduction of optical bandgap from 4.71 to 2.90 eV, resulting from enhanced charge transfer between the layers and defect states due to the addition of nanofillers. The incorporation of MoS2 increase the specific capacitance of the PS from 2.78 to 124.98 F g−1 at a current density of 0.10 mA g−1. The EIS analysis revealed that the nanofiller significantly reduces the charge transfer resistance from 4574 to 0 Ω, facilitating the ion transportation between the layers. The PS/rGO/MoS2 nanocomposite also exhibited excellent stability, retaining about 85% of its capacitance up to 10,000 charging-discharging cycles. These biocompatible polymer-based nanocomposites with improved electrochemical performance synthesized from an easy and economical route may offer a promising direction to fabricate a nature-friendly electrode material for energy storage applications.

Flexible pressure sensor based on multi-layer with gradient structure P(VDF-HFP)/MXene/BaTiO3 composite film for human motion monitoring

In recent years, flexible pressure sensors have been widely used in fields such as human health monitoring, flexible energy storage, wearable electronic devices, and flexible sensing due to their advantages of simple and efficient preparation process, highly sensitive, fast response, and strong piezoelectric performance. In this paper, we studied a kind of polyvinylidene fluoride hexafluoropropylene (P(VDF-HFP))/MXene/BaTiO3 nanofiber prepared by electrospinning technology, and designed a multi-layer structure system with gradient to prepare a flexible pressure sensor. The piezoelectric properties, mechanical properties and dielectric properties are obviously improved. At the same time, the addition of nano fillers and structural design have increased the sensitivity of multi-layer composite fiber membrane-based sensors by 16.5 times compared to pure P(VDF-HFP) in the low-pressure range (<1 kPa), and by 1.5 times compared to PFP-0.5M5BT nanofiber-based sensors, reaching 0.23 kPa−1. When pressed by the palm of the hand, the output voltage of the three-layer gradient structure thin film sensor can be up to about 100 V. Compared with the output voltage of 5 V when the P(VDF-HFP) thin film is pressed by the palm, the output voltage of the flexible pressure sensor of the three-layer gradient structure thin film after adding the filler is 20 times higher. The flexible pressure sensor can analyze and recognize the form of human motion based on the peak, frequency, and shape characteristics of the voltage signals generated by different forms of human motion. This makes it possible for flexible pressure sensors to be used in pressure detection, flexible sensing, electronic skin sensors and other fields.

Towards more homogeneous character in 3D printed photopolymers by the addition of nanofillers

The performance of 3D printed materials differs from that of fully cured polymer materials because of the presence of interfacial areas between consecutively joined layers. These interfaces result in an inhomogeneous character of the printed objects and is frequently reported as their main cause of failures. We noted that the presence of nanosilica particles strengthens the 3D printed layers of the polymer matrix by inducing its additional crosslinking. A model resin composed of poly (ethylene glycol) diacrylate (PEGDA) and nanosilica (Aerosil R972) is used for vat photopolymer 3D printing. Evolution of the interface properties at different nanosilica loadings is tracked by mapping its surface stiffness (Young's modulus mapping) using quantitative Atomic Force Microscopy (AFM). Our research demonstrates that incorporating 6% w/v nanosilica in the polyPEGDA matrix unifies its mechanical properties within the layer, leading to a substantial reduction of microscopic inhomogeneity in the final 3D printed materials.

Ballistic impact performance of hybrid composite armors made of aluminum foam containing the dispersion of shear thickening fluid made of various synthetic nano-fillers

Hybrid composites armors made of closed-cell aluminum foam are developed for intended use in ballistic protective plates. The manufacturing process involved impregnation of shear thickening containing different micro and nano-fillers into aluminum foam panels which are subsequently bonded two AA 5086-H32 aluminum sheets that surrounded the targets, by using compression molding techniques. The effects of the addition of different nano-fillers as colloidal silica, gamma alumina, silica carbide, and Kevlar micro-fibers to the aluminum foam plates on the ballistic response of the hybrid composites armors were investigated. Scanning electron micrographs were used to investigate the interfacial interaction between specimen layers, and the influence of the nanoparticles impregnated within closed aluminum foam cells before and after high-velocity impacts. The ballistic impact resistance of the produced hybrid composite cell aluminum foam laminates was tested according to NATO standards using a semiautomatic 9 mm Beretta Cx4 Storm Rifle Luger. The results indicated that the performance of the hybrid composite armors made of aluminum foam were enhanced by the deposition of micro and nano-fillers into the surface of the closed-cell aluminum foam.Therefore, the ballistic impact resistance and energy absorption of the specimens were improved. The highest impact energy absorption capacity was achieved by the deposition of Kevlar micro-fibers, but the resulting plates have the highest target weight and thickness. Silica carbide powder followed by gamma alumina, and colloidal silica powder in that order, enhanced the impact energy absorption capability with the least target weight and thickness average. These findings indicate that introduction of micro and nano-fillers coating on closed-cell aluminum foam, improved a range from 4.9 to 30.9 J in comparison with untreated samples, therefore, it could be a promising method for strengthening interfacial bonding between layers of the aluminum foam composites.

Development of reduced graphene oxide (rGO) reinforced poly(lactic) acid/ cellulose nanocrystal composite through melt mixing: Effect of nanofiller on thermal, structural, biodegradation and antibacterial properties

The intent of this research work was to synthesised a synthetic polymer that is biodegradable, bioresorbable, and biocompatible, while also exhibiting favorable thermal characteristics. The present study reports the successful fabrication of bionanocomposites by incorporating Cellulose nanocrystals (CNCs) and Reduced graphene oxide (rGO) into host matrix (PLA) using the melt-mixing technique. Various weight percentages (wt%) of rGO were employed in the process and various characterization techniques, including BET analysis, XRD, FTIR and field emission scanning electron microscopy (FE-SEM) were used to verify the efficient fabrication of a number of nanoformulations and nanofiller’s effect. Introduction of CNC and rGO in PLA matrix increases the surface area as well as porosity of the composites, established by BET analysis. DSC results indicate that the assimilation of rGO into the polymer matrix improved thermal stability of the composite material and leads to boost in the degree of crystallinity which was supported by XRD analysis. TGA results found no noticeable change in glass transition temperature (Tg) due to the addition of Nanofiller (rGO). The wettability analysis was done by contact angle measurement to determine the hydrophilicity of the composite and it is shown that with the increasing amount of rGO, hydrophilicity increases and contact angle reaches to 69° for 0.75 wt% of rGO in composite in comparision to 100° Neat PLA. The rGO/CNC/PLA nanocomposites exhibit a unique antibacterial effectiveness against both the S. aureus (Gram-positive) and E. coli (Gram-negative) bacterial strains. The highest antimicrobial activity was obtained in the nanocomposite tested against S. aureus. Biodegradation through Lysozyme in PBS solution shows promising result after incorporation of nanofillers. Hence, the nanocomposite manufactured through melt mixing process has promising uses in the biomedical and food packaging industries.

Nano‐hydroxyapatite reinforced polylactic acid bioabsorbable cancellous screws for bone fracture fixations

AbstractBioabsorbable polymer implants aid the fracture treatment to overcome the limitations of metallic implants like stress shielding, corrosion, and revision surgeries. The cancellous screw is one of the internal fixation implants more frequently used in fixation procedures. In this work, nano‐hydroxyapatite (nHAp) reinforced polylactic acid cancellous screws were developed for bone fracture treatment. The biocompatibility and mechanical tests were performed before and after in‐vitro hydrolytic degradation studies. The addition of nanofillers (10 wt% nHAp) enhanced the pullout strength, torsional strength, and shear strength by 18%, 48%, and 5%, respectively. The performed thermal studies confirmed that the nanohydroxyapatite facilitates the crystallization process. A mass loss of about 18% in the case of neat PLA and 12% in the case of 10 wt% nHAp was observed for 90 days of in‐vitro hydrolytic degradation studies. So, the developed combination of biocomposite could help fabricate patient‐specific bioabsorbable fixation devices like screws and plates.

Retracted: Effect of Aluminium Tetrahydrate Nanofiller Addition on the Mechanical and Thermal Behaviour of Luffa Fibre-Based Polyester Composites under Cryogenic Environment

Retracted: Effect of Aluminium Tetrahydrate Nanofiller Addition on the Mechanical and Thermal Behaviour of Luffa Fibre-Based Polyester Composites under Cryogenic Environment

Micromechanical modeling of devulcanized ground tyre rubber, graphene platelets, and carbon black in recycled natural rubber blends

AbstractWaste tyres are a global problem, with 1.5 billion being generated annually. To reduce this problem, a circular economy for tyres should be developed. This requires the incorporation of recycled tyre rubber in tyre products. Yet, most recycled rubber is of insufficient quality. Recycled rubber must react sufficiently well with virgin rubber to be elastically effective in the 3D crosslinked network. Although a broad range of devulcanization techniques have been developed, many recycled‐virgin rubber blends show significant reductions in stiffness compared with their virgin counterparts. This paper demonstrates that micromechanical models for filler reinforcement can be used to evaluate whether recycled rubber behaves in an elastically effective manner. Furthermore, mechanical devulcanization of ground tyre rubber (GTR) by solid‐state shear milling was shown to produce a recycled rubber powder that is elastically effective when blended with virgin natural rubber (vNR). These blends match the equivalent virgin rubber stiffness, despite high‐recyclate content (30/70 vNR/GTR). The addition of nanofillers (carbon black and graphene nanoplatelets) to these blends was evaluated to see how they compared with virgin compounds and filler reinforcement theories. This process may allow for incorporation of devulcanized rubber into existing products, promoting a circular economy for high‐value rubber recycling.

Preparation and Characterization of Low CTE Poly(ethersulfone) Using Lignin Nano Composites as Flexible Substrates.

Polyethersulfone (PES) has outstanding thermal and dimensional stability. It is considered an engineering thermoplastic. However, its high coefficient of thermal expansion (CTE) hinders its use in automobiles, microelectronics, and flexible display areas. To overcome its high coefficient of thermal expansion (CTE), recent studies have focused on reducing its high CTE and improving its mechanical properties by adding nano-sized fillers or materials. The addition of nanofiller or nanofibrils to the PES matrix often has a positive effect on its mechanical and thermal properties, making it a flexible display substrate. To obtain ideal flexible substrates, we prepared polyethersulfone with lignin nanocomposite films to reduce CTE and improve the mechanical and thermal properties of PES by varying the relative ratio of PES in the lignin nanocomposite. In this study, lignin as a biodegradable nanofiller was found to show high thermal, oxidative, and hydrolytic stability with favorable mechanical properties. PES/lignin nanocomposite films were prepared by solution casting according to the content of lignin (0 to 5 wt.%). PES/lignin composite films were subjected to mechanical, thermo-mechanical, optical, and surface analyses. The results showed enhanced thermomechanical and optical properties of PES, with the potential benefits of lignin filler materials realized for the development of thermoplastic polymer blends.

Recent Advances in Membranes Used for Nanofiltration to Remove Heavy Metals from Wastewater: A Review.

The presence of heavy metal ions in polluted wastewater represents a serious threat to human health, making proper disposal extremely important. The utilization of nanofiltration (NF) membranes has emerged as one of the most effective methods of heavy metal ion removal from wastewater due to their efficient operation, adaptable design, and affordability. NF membranes created from advanced materials are becoming increasingly popular due to their ability to depollute wastewater in a variety of circumstances. Tailoring the NF membrane's properties to efficiently remove heavy metal ions from wastewater, interfacial polymerization, and grafting techniques, along with the addition of nano-fillers, have proven to be the most effective modification methods. This paper presents a review of the modification processes and NF membrane performances for the removal of heavy metals from wastewater, as well as the application of these membranes for heavy metal ion wastewater treatment. Very high treatment efficiencies, such as 99.90%, have been achieved using membranes composed of polyvinyl amine (PVAM) and glutaraldehyde (GA) for Cr3+ removal from wastewater. However, nanofiltration membranes have certain drawbacks, such as fouling of the NF membrane. Repeated cleaning of the membrane influences its lifetime.