Functional Polymer Nanocomposites Research Articles

CNT/TiO2 nanocomposite for environmental remediation

Abstract Nanomaterials and their composites have been proven to be effective materials for various energy and environmental applications. In this way, functionalized polymers and their nanocomposites (NCs) are receiving much attention due to their tunable physico-chemical characteristics, cost and ease of availability. As an environmental application, particularly the removal of toxic dyes, photocatalysis has been reported as an emerging technology. The literature survey shows that functionalized polymer nanocomposites (PNCs) as photocatalysts offer an extensive contribution towards the generation of clean, renewable, and practical forms of energy from light-based pollutant removal as environmental remediation. Here, the present concept provides a brief introduction to the field of photocatalysis and environmental remediation, followed by the application of functionalized PNCs. In this view, TiO2–NCs are reported to be effective photocatalytic materials. In the present study, CNT-doped TiO2 NCs samples have been prepared using the sol–gel method and their photocatalytic activity has been investigated through a dye degradation experiment. Compared to the present studies, here the CNT content taken is very low, and it is found to be effective for the dye degradation part of an environmental cleaning application.

Functional Technical Textile-Based Polymer Nanocomposites with Adsorbent Properties of Toxins and Dyes also Have Antibacterial Behavior.

This is the first study of non-woven fabrics elaborated by melt-blowing from polymer nanocomposites made of Nylon 6 and nanoclay (Cloisite 20A) modified with an amine (1,4 diaminobutane dihydrochloride). Morphological and physical characteristics, adsorption capacity, and antibacterial properties are presented. From the X-ray diffraction (XRD) results, it was possible to observe a displacement of the signals to other 2θ angles, due to an α to ϒ phase shift. The scanning electron microscopy (SEM) images showed that the mean diameter of fiber decreased as the content of nanoclay increased. The mechanical tests showed that the tear strength force of neat nylon was 1.734 N, but this characteristic increased to 2.135 N for the sample with 0.5% modified nanoclay. The inulin adsorption efficiency of the Nylon 6/C20A 1.5% and Nylon 6/C20A 2% samples at 15 min was 75 and 74%, respectively. The adsorption capacity of Nylon 6/C20A 1.5% and Nylon 6/C20A 2% for methylene blue and methyl orange remained above 90% even after four adsorption cycles. In addition, non-woven fabrics present antibacterial activity against E. coli.

Recent Advances in pH and Redox Responsive Polymer Nanocomposites for Cancer Therapy

Cancer therapy currently focuses on personalized targeted treatments. A promising approach uses stimuli-responsive biomaterials for site-specific drug release, such as pH- and redox-triggered polymer nanocomposites. These materials respond to the tumor microenvironment, enhance efficacy, and reduce off-target effects. Cancer cells with anomalous properties such as acidic cytosolic pH and elevated redox potential are targeted by these biomaterials. An imbalance in ions and biological thiols in the cytoplasm contributes to tumor growth. Functionalized polymer nanocomposites with large surface areas and specific targeting outperform conventional small-molecule materials. To overcome problems such as low bioavailability, uncontrolled drug release, and poor cell penetration, multifunctional nanomaterials make it easier for drugs to enter certain cellular or subcellular systems. High therapeutic efficacy is achieved through surface functionalization, site-specific targeting, and the use of stimuli-responsive components. In particular, pH and redox dual-stimuli-based polymeric nanocomposites for cancer therapeutics have scarcely been reported. This article provides recent progress in pH- and redox-responsive polymer nanocomposites for site-specific drug delivery in cancer therapy. It explores the design principles, fabrication methods, mechanisms of action, and prospects of these dual-stimuli-responsive biomaterials.

Robust Strategy to Improve the Compatibility between Incorporated Upconversion Nanoparticles and the Bulk Transparent Polymer Matrix.

Traditional transparent polymer nanocomposites combined with functional fluorescent inorganic nanofillers are promising for many advanced optical applications. However, the aggregation of the incorporated functional nanoparticles results in light scattering and will decrease the transparency of nanocomposites, which will restrain the application of the transparent nanocomposites. Herein, a robust synthesis strategy was proposed to modify upconversion nanoparticles (UCNPs) with polymethyl methacrylate (PMMA) to form UCNP@PMMA core@shell nanocomposites though metal-free photoinduced surface-initiated atom transfer radical polymerization (photo-SI-ATRP), and thus, the dispersity of UCNP@PMMA and the interface compatibility between the surface of UCNPs and the bulk PMMA matrix was greatly improved. The obtained PMMA nanocomposites possess high transparency and show strong upconversion photoluminescence properties, which promises great opportunities for application in 3D display and related optoelectronic fields. This strategy could also be applied to fabricate other kinds of functional transparent polymer nanocomposites with inorganic nanoparticles uniformly dispersed.

Functional Polymer Nanocomposites with Increased Anticorrosion Properties and Wear Resistance for Water Transport.

Corrosive destruction and hydroabrasive wear is a serious problem in the operation of machine parts and water transport mechanisms. It is promising to develop new composite materials with improved properties to increase the reliability of transport vehicles. In this regard, the use of new polymer-based materials, which are characterized by improved anticorrosion properties and wear resistance, is promising. In this work, therefore, for the formation of multifunctional protective coatings, epoxy dian oligomer brand ED-20, polyethylene polyamine (PEPA) hardener, a mixture of nanodispersed compounds with a dispersion of 30-90 nm, fillers Agocel S-2000 and Waltrop with a dispersion of 8-12 μm, and particles of iron slag with a dispersion of 60-63 μm are used for the formation of multifunctional protective coatings. Using the method of mathematically planning the experiment, the content of additives of different physico-chemical natures in the epoxy binder is optimized to obtain fireproof coatings with improved operational characteristics. A mathematical model is developed for optimizing the content of components in the formation of protective anticorrosion and wear-resistant coatings for means of transport as a result of the complex effect of a mixture of nanodispersed compounds, iron scale, and Waltrop. Based on the mathematical planning of the experiment, new regularities of increasing the corrosion resistance and resources of the means of transport are established through the formation of four different protective coatings, which are tested for resistance to aggressive environments (technical water-CAS No. 7732-18-5, gasoline-CAS No. 64742-82-1, acetone-CAS No. 67-64-1, I-20A lubricant-CAS No. 64742-62-7, sodium solutions-CAS No. 1310-73-2, and sulfuric acid-CAS No. 7664-93-9) and hydroabrasive wear resistances. A study of the change in the permeability index in aggressive environments is additionally carried out, taking into account the rational ratio of dispersive fillers in the epoxy binder, which made it possible to create an effective barrier to the penetration of aggressive water molecules into the base. A decrease in the permeability of protective coatings by 2.0-3.3 times relative to the epoxy matrix is achieved. In addition, the wear resistance of the developed materials under the action of hydroabrasion is investigated. The relative resistance of the CM to the action of hydroabrasion was found by the method of materials and coatings testing on the gas-abrasive wear with a centrifugal accelerator. This method enables one to model the real process of the wear of mechanism parts under the hydroabrasive action. It is shown that the coefficient of the wear resistance of the developed materials is 1.3 times higher than that of the polymer matrix, which indicates the resistance of the composites to the influence of hydroabrasive environment. As a result, modified epoxy composite protective coatings with improved anticorrosion properties and wear resistance under hydroabrasive conditions are developed. It is established that the protective coating filled with particles of a mixture of nanodispersed compounds (30-90 nm), iron scale (60-63 μm), and Waltrop (8-12 μm) has the lowest permeability indicators. The permeability in natural conditions of such a coating during the time t = 300 days of the study is χ = 0.5%, which is 3.6 times less than the similar indicators of the epoxy matrix. It is substantiated that the protective coating filled with particles of a mixture of nanodispersed compounds (30-90 nm), iron scale (60-63 μm), and Agocel S-2000 (8-12 μm) is characterized by the highest indicators of wear resistance. The coefficient of wear resistance under the action of hydroabrasion of such a coating is K = 1.75, which is 1.3 times higher than the similar indicators of the original epoxy matrix.

Progressive Review of Functional Nanomaterials-Based Polymer Nanocomposites for Efficient EMI Shielding

Nanomaterials have assumed an imperative part in the advancement of human evolution and are more intertwined in our thinking and application. Contrary to the conventional micron-filled composites, the unique nanofillers often modify the properties of the polymer matrix at the same time, bestowing new functionality because of their chemical composition and their nano dimensions. The unprecedented technological revolution is driving people to adapt to miniaturized electronic gadgets. The sources of electromagnetic fields are ubiquitous in a tech-driven society. The COVID-19 pandemic has escalated the proliferation of electromagnetic interference as the world embraced remote working and content delivery over mobile communication devices. While EMI shielding is performed using the combination of reflection, absorption, and electrical and magnetic properties, under certain considerations, the dominant nature of any one of the properties may be required. The miniaturization of electronic gadgets coupled with wireless technologies is driving us to search for alternate lightweight EMI shielding materials with improved functionalities relative to conventional metals. Polymer nanocomposites have emerged as functional materials with versatile properties for EMI shielding. This paper reviews nanomaterials-based polymer nanocomposites for EMI shielding applications.

Recent progress and perspective in additive manufacturing of EMI shielding functional polymer nanocomposites

Recent progress and perspective in additive manufacturing of EMI shielding functional polymer nanocomposites

Additive manufacturing of smart polymeric composites: Literature review and future perspectives

AbstractThe latest developments in smart systems for improved human lives with advanced biomedical devices have evolved out of multi‐disciplinary scientific studies, including medicine, biology, material sciences, design, manufacturing, artificial intelligence, microelectronics, and so forth. The growth of such intelligent systems is primarily possible with innovative materials, which demonstrate the response to various external stimuli like temperature, heat, moisture, light, electromagnetic field, and chemical alteration. Such materials have been recently fabricated using different additive manufacturing techniques to devise personalized unique, complex, and novel structures that can adjust to external conditions over time and are specifically attributed to 4D printing. Novel materials that can further improve such systems continued to be explored and employed. This review paper investigates the additive manufacturing of functional polymer nanocomposites, which offer compliant structures with flexible manufacturing processes with high strength, low cost, and long‐term stability. This study aims to deliver a comprehensive and deep understanding of the latest developments in materials, design, manufacturing, fundamental mechanisms involved, and future possibilities in this area of research.

Advancements in Bioelectricity Generation Through Nanomaterial-Modified Anode Electrodes in Microbial Fuel Cells

The use of nanotechnology in bioelectrochemical systems to recover bioelectricity and metals from waste appears to be a potentially appealing alternative to existing established procedures. This trend exactly characterizes the current renewable energy production technology. Hence, this review focuses on the improvement of the anode electrode by using different functional metal oxide-conducting polymer nanocomposites to enhance microbial fuel cell (MFC) performance. Enhancement of interfacial bioelectrocatalysis between electroactive microorganisms and hierarchical porous nanocomposite materials could enhance cost-effective bioanode materials with superior bioelectrocatalytic activity for MFCs. In this review, improvement in efficiency of MFCs by using iron oxide- and manganese oxide-based polypyrrole hybrid composites as model anode modifiers was discussed. The review also extended to discussing and covering the principles, components, power density, current density, and removal efficiencies of biofuel cell systems. In addition, this research review demonstrates the application of MFCs for renewable energy generation, wastewater treatment, and metal recovery. This is due to having their own unique working principle under mild conditions and using renewable biodegradable organic matter as a direct fuel source.

3D‐Printed Functional Polymers and Nanocomposites: Defects Characterization and Product Quality Improvement

There have been continuing efforts toward improving printability and minimizing defects in 3D‐printed functional polymers and polymer nanocomposites (PNCs). While printability is essentially material related, and formation of defects is largely influenced by operational parameters, there is an interconnection between the factors influencing both. It is important to have a comprehensive insight on how these aspects interrelate to increase the prospect of improving part performance and widening the current range of applications of 3D‐printed polymer‐based functional materials. Therefore, this work first reviews various polymer 3D printing techniques and recent advances in 3D‐printed functional polymers and PNCs before discussing characterization and control of common defects in printed parts. Techniques for improving printability of polymer‐based functional materials are then discussed. Some opportunities for further developments in this area are highlighted in respect of polymer blending, immiscible blend nanocomposites, and a specific product development prospect.

Kinetics of high density functional polymer nanocomposite formation by tuning enthalpic and entropic barriers.

High density functional polymer nanocomposites (PNCs) with high degree of dispersion have recently emerged as novel materials for various thermo-mechanical, optical and electrical applications. The key challenge is to attain a high loading while maintaining reasonable dispersion to attain maximum possible benefits from the functional nanoparticle additives. Here, we report a facile method to prepare polymer grafted nanoparticle (PGNP)-based high density functional polymer nanocomposites using thermal activation of a high density PGNP monolayer to overcome entropic or enthalpic barriers to insertion of PGNPs into the underlying polymer films. We monitor the temperature-dependent kinetics of penetration of a high density PGNP layer and correlate the penetration time to the effective enthalpic/entropic barriers. The experimental results are corroborated by coarse-grained molecular dynamics simulations. Repeated application of the methodology to insert nanoparticles by appropriate control over temperature, time and graft-chain properties can lead to enhanced densities of loading in the PNC. Our method can be engineered to produce a wide range of high density polymer nanocomposite membranes for various possible applications including gas separation and water desalination.

Functionalization of PMMA/TiO2 nanocomposites: Synthesis, characterization and their antioxidant and antibacterial evaluation

AbstractThe present work reports the functionalization of PMMA and its nanocomposites were synthesized via simple solution mixing method. Functionalization of PMMA with different amino containing groups, that is, ethylene diamine (ED) and 4‐amino benzoic acid (PA) and used with low dosage (1 wt% and 3 wt%) of TiO2 nanoparticles (NPs) to form nanocomposites. The morphology was determined by SEM, average particle size (50 nm) of TiO2 NPs was measured by TEM. The pore radius (14.47 A°) and specific surface area (157.89 m2/g) of TiO2 NPs were measured by BET analysis. FT‐IR and NMR analysis confirms the functionalization of PMMA. The antioxidant activity of functionalized PMMA and its nanocomposites have been analyzed by using 2,2 diphenyl‐1‐picryhydrazyl (DPPH) assay. The antibacterial activity against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) of functionalized polymer nanocomposites were investigated. The result revealed that functionalized PMMA (PMPA) shows maximum antioxidant activity. The increase in concentration of TiO2 NPs efficiently augments the bacterial inhibition against Gram‐negative and Gram‐positive bacteria. The maximum zone of inhibition (ZOI) was recorded against E. coli ATCC 25922 (30 mm) and S. aureus ATCC 29213 (31 mm) and minimum inhibitory concentration (MIC) over E. coli (64 μg/ml) and S. aureus (32 μg/ml) by PMPA2. The synthesized functionalized PMMA nanocomposites can be considered as promising material for biological applications.

Engineering at the Nanoscale: A Strategy for Developing High-Performance Functional Polymer Nanocomposites

The talk will concentrate on various approaches being used to engineer materials at the nanoscale for various applications in future technologies. In particular, the case of clay, carbon nanostructures (e.g., nanotubes, graphene), metal oxides, bionanomaterials (cellulose, starch, and chitin) will be used to highlight the challenges and progress. Several bio-degradable polymer systems will be considered, such as rubbers, thermoplastics, thermosets, and their blends for the fabrication of functional polymer nanocomposites. The interfacial activity of nanomaterials in compatibilism binary polymer blends will also be discussed. Various self-assembled architectures of hybrid nanostructures can be made using relatively simple processes. Some of these structures offer an excellent opportunity to probe novel nanoscale behavior and can impart unusual macroscopic end properties. I will talk about various applications of these materials, taking into account their multifunctional properties. Some of the promising applications of clay, metal oxides, nano cellulose, chitin, carbon nanomaterials, and their hybrids will be reviewed.

Enhanced mechanical properties of functionalized BN nanosheets-polymer composites

Liquid exfoliated, hydroxylated functionalized hexagonal boron nitride nanosheets (h-BNNSs-OH) are prepared for improved dispersion in polymers. Polymer nanocomposites are fabricated using (0–0.03 Vf) hydroxyl (OH) functionalized and non-functionalized BNNSs with poly methyl methacrylate, PMMA, by solution mixing for comparative study. Mechanical properties of the composites are improved considerably. The maximum ultimate tensile strength of the functionalized BN/PMMA (0.003 Vf BN) reached to ~ 26 MPa as compared to non-functionalized composites maximum value of ~ 19 MPa while the base polymer value remained at ~ 15 MPa. The Young’s modulus enhanced as well from 1.45 GPa (PMMA) to 2.01 GPa and 2.19 GPa both for non-functionalized and functionalized composites respectively. The degree of reinforcement validated with the Halpin–Tsai Model is in close agreement for functionalized polymer nanocomposites. Structural and morphological characteristics are analyzed using X-ray Diffraction (XRD) and scanning electron microscopy (SEM) respectively, confirming the composites formation. The lateral dimension of the synthesized nanosheets is estimated with SEM as well. Dimensional analysis of nanosheets is carried out using atomic force microscopy (AFM). The estimated thickness of functionalized hBN flakes was around 5–10 nm. Fourier transform infra-red spectroscopy (FTIR) is used to confirm the presence of functional groups on h-BN. Differential scanning calorimeter (DSC) is used to study the polymer and nanosheets interactions.

Poly(butylene succinate) and graphene nanoplatelet–based sustainable functional nanocomposite materials: structure-properties relationship

Sustainable functional polymer nanocomposites from renewable resources are extremely promising materials that can provide the next-generation of lightweight, multifunctional materials for several applications including energy storage, automotive, construction, defense, aerospace, consumer products, biomedical and functional coatings to name few. There is limited information on the use of sustainable polymers and graphene nanoplatelets (GNs), as well as the combinations of these two can provide reduced water permeability or enhanced electrical conductivity and improved thermal properties, and so on. Building upon this hypothesis, biobased poly(butylene succinate)/few-layer GN nanocomposites were prepared via a solventless melt-blending technique. Different characterization techniques such as differential scanning calorimetery, thermogravimetric analysis, dynamic mechanical analysis, dielectric spectroscopy, X-ray diffraction (XRD) and hot stage optical microscopy were used to study the thermal and structural characteristics. The melt blending was characterized by torque and temperature curves which showed that torque was reduced by up to 15 Nm, and melt temperature was improved by up to 5 °C. The improved crystallization of the composites in low concentrations of GN was observed. Graphene has been found to increase the crystallization temperature up to 10 °C and yielded pronounced spherulite structure, whereas peak shift was observed in XRD. High filler loading from 0.5 to 6.0 wt% was used to obtain more insights for few-layer graphene applications for thermoplastic polymer processing applications.

In-situ synthesis of 3D printable mono- and Bi-metallic (Cu/Ag) nanoparticles embedded polymeric structures with enhanced electromechanical properties

The interest of additive manufacturing with 3D printing increases day by day, which provides improved mechanical, electrical, magnetic and thermal properties of 3D parts. The production of 3D parts with the stereolithography (SLA) method, which allows it to be produced with high precision, resolution and complex geometries, distinguishes itself from other alternative additive manufacturing methods (FDM. SLS. LOM. LMD etc.). However, studies on the preparation of functional 3D polymer nanocomposites with the SLA method are quite limited. This study aims to produce silver (Ag) and/or copper (Cu) based 3D polymer nanocomposites for enhancing its mechanical strength, thermal stability and electrical conductivity. Mono and bimetallic (Cu/Ag) nanoparticles have been in-situ synthesized by selective irradiation of laser beam method using a commercial SLA device. In this method, metal (Cu/Ag) acrylate containing photocurable resin is not only cured but also leads to thermal decomposition of metal ions into nanoparticles to form functional 3D structures. The mechanical, electrical and thermal properties of polymer nanocomposites are characterized in detail. As a result of the analysis, the nanoparticles, with an average diameter of 25–55 nm, are well dispersed in the polymer matrix without agglomeration. The temperature at which 5% weight loss of Ag and Cu based polymer structures is measured as 179.3 °C while the glass transition temperature is found to be 223.81 °C. Most importantly, the resistance values are significantly decreased from 456.62 GΩ (Gigaohm) to 1.50 GΩ by increasing the amount of Ag addition at 3D polymeric structures. Therefore, this study allows the production of polymer nanocomposites not only in complex structures but also in desired properties especially for electrically conductive materials, capacitors and electronic applications.

Concentration-Dominated Orientation of Phenyl Groups at the Polystyrene/Graphene Interface.

The interfacial orientation of aromatic groups plays a crucial role in determining the properties of graphene-based aromatic polymer nanocomposites. Here, the interfacial orientation of the polystyrene (PS) phenyl groups in contact with graphene is revealed by sum frequency generation (SFG) vibrational spectroscopy. The SFG spectra showed that the orientation of the phenyl groups is closely related to the interfacial concentration as the chains reach the quasi-equilibrium state. The phenyl groups remain in a relatively unrestricted state at a low concentration of the PS phenyl groups, and they prefer to recline to more favorably interact with graphene via a face-to-face configuration. Densely stacked phenyl groups are too crowded to form multilayer face-to-face interactions with graphene, and they prefer to remain upright, while π-π interactions are formed among the phenyl groups themselves in addition to the edge-to-face interactions to maximize the bonding energy of the π-π interactions. This is enthalpically favorable and driven mainly by the π-π interactions. This work provides important knowledge for the design and optimization of functional graphene-based aromatic polymer nanocomposites.

Biodegradable and Antimicrobial PLA-OLA Blends Containing Chitosan-Mediated Silver Nanoparticles with Shape Memory Properties for Potential Medical Applications.

To use shape memory materials based on poly (lactic acid) (PLA) for medical applications is essential to tune their transition temperature (Ttrans) near to the human body temperature. In this study, the combination of lactic acid oligomer (OLA), acting as a plasticizer, together with chitosan-mediated silver nanoparticles (AgCH-NPs) to create PLA matrices is studied to obtain functional shape memory polymers for potential medical applications. PLA/OLA nanocomposites containing different amounts of AgCH-NPs were obtained and profusely characterized relating their structure with their antimicrobial and shape memory performances. Nanocomposites exhibited shape memory responses at the temperature of interest (near physiological one), as well as excellent shape memory responses, shorter recovery times and higher recovery ratios (over 100%) when compared to neat materials. Moreover, antibacterial activity tests confirmed biocidal activity; therefore, these functional polymer nanocomposites with shape memory, degradability and biocidal activity show great potential for soft actuation applications in the medical field.

Elastomer nanocomposites containing MXene for mechanical robustness and electrical and thermal conductivity

A novel 2D nanomaterial, Ti3C2Tx MXene, added conductivity and reinforcement to a common elastomer, nitrile butadiene rubber (NBR). X-ray diffraction revealed the intercalation of lithium ions and elastomer chains into the MXene interlayer spacing, which enabled exfoliation in the elastomer. The reaction between MXene and NBR was proved by a stepwise Fourier transform infrared spectroscopy. With increase in MXene fractions, electrical and thermal conductivity of the composite increased to 9 × 10−5 S cm−1 and 0.69 W m−1 K−1, respectively. At only 2.8 vol% MXene, a swelling ratio of 1.61 was achieved, representing a 75% reduction compared to NBR containing either graphene or carbon nanotubes at the same filler fraction. Tensile tests showed that with the increase in MXene content, Young’s modulus increased while both tensile strength and elongation at break first increased and then decreased. Overall, latex compounding proved to be an efficient technique for forming NBR/MXene nanocomposites. The revealed reaction between MXene and NBR to create functional polymer nanocomposites could provide a platform for utilising MXene for other polymers.

An electrospun polymer composite with fullerene-multiwalled carbon nanotube exohedral complexes can act as memory device

Functional polymer nanocomposites with distinctive electrical properties made of nanocarbon structures and biodegradable polymers are promising materials for the development of flexible and eco-friendly smart systems. In this work, a novel electrospun conductive polymer nanocomposite made of polycaprolactone with an exohedral complex made of multiwalled carbon nanotubes and fullerene C60 was prepared and characterized. The preparation was straightforward and the complexes self-assembled within the nanocomposite fibers. The nanocomposite showed electrical switching behavior due to charge accumulation of fullerene C60 upon electrical stimulation. Write-once read-many memory devices were fabricated by electrospinning a nanocomposite with 0.8%wt. fullerene C60 onto interdigitated coplanar electrodes. The device retained the ON state for more than 60 days and could be thermally reset, reprogrammed and erased with subsequent electrical and thermal cycling. Moreover, the electrical resistance of the device could be modulated by applying different programming voltage amplitudes and programming times, which revealed its adaptive behavior and potential application to neuromorphic systems.