Use Of Polymer Nanocomposites Research Articles

An experimental-analytical investigation of particle size effect on the mode I fracture behavior of polymer/graphene nanocomposites

Due to their outstanding specific mechanical and functional properties, the engineering use of polymer nanocomposites and their carbon composites is becoming increasingly pervasive. Current and potential applications include micro- and flexible electronics, energy storage devices, and the use as reinforcement for advanced carbon fiber composites for light-weighting of aerospace and mechanical structures, thereby reducing their fuel consumption and carbon footprint. While a large amount of data and models regarding the effect of the weight fraction of nanoplatelets on the mechanical properties of nanocomposites is currently available in the literature, an aspect often overlooked is the scaling of the fracture behavior and the related particle size effects. Not only is the lack of understanding of size effects in nanomaterials hindering the full exploitation of their properties, it is also a serious issue since the design of large nanocomposite structures or small-scale electronic components requires capturing the scaling of their mechanical properties and developing predictive capabilities. This paper aims at filling this knowledge gap by proposing a novel analytical and experimental approach to investigate particle size effects in nanocomposites at and leveraging the acquired knowledge to improve their fracture properties, from the nanoscale all the way to the macroscale. To this end, crack initiation fracture toughness data for graphene/epoxy nanocomposite are presented as a function of nanoparticle size and weight fraction and compared with model predictions using a novel analytical model based on enhanced crack-tip shielding effect due to the reduced nanoparticle size. Extensive fracture test data are presented for model calibration and model verification.

Polymer Nanocomposites: A Comprehensive Review on Their Applications in Membranes and Adsorbents for Water Treatment and Gas Separation

Environmental challenges such as water scarcity and air pollution have become critical global issues, prompting the need for innovative solutions. Polymer nanocomposites have emerged as promising materials for addressing these challenges due to their unique properties and functionalities. This comprehensive review explores the effective utilization of polymer nanocomposites in membranes and adsorbents for water treatment and gas separation. The synthesis methods, properties, and mechanisms of polymer nanocomposite membranes are discussed, along with their applications in wastewater treatment and gas separation. Furthermore, the use of polymer nanocomposites as adsorbents for removing toxic metals ions and dyes from water is examined, including the underlying adsorption mechanisms. Additionally, the review highlights recent patents in the field, emphasizing the innovative applications of polymer nanocomposite membranes for environmental purposes

ОГЛЯД МЕХАНІЧНИХ ВЛАСТИВОСТЕЙ НАНОКОМПОЗИТІВ НА ПРЕДМЕТ ЇХ ВИКОРИСТАННЯ У ПАРАХ КОВЗАННЯ МЕХАНІЗМІВ АВІАТЕХНІКИ

The object of the review is polymer nanocomposites (PNC), which are used to increase the wear resistance and durability of mechanical contacting surfaces of parts of machines and mechanisms. The goal is to analyze the production and mechanical properties of PNC when they are used in aircraft and helicopter structural units operating in sliding pairs with a large resource. The analysis of existing research and publications on the use of PNC showed that the use of nanocomposites with a plastic base can be recommended for the manufacture of tribological pairs of aircraft parts. It was established that most authors among the considered nanoadditives give preference to nanodiamonds with a concentration in the range of 1...3%, which, in comparison with all other nanomaterials, give a consistently positive result and also have good environmental indicators.It was found that for parts of friction pairs it is possible to provide a friction coefficient of about 0.1 due to the use of composite polymers with ND. The following results were obtained. The performed review will allow to create a regulatory base of nanomaterials, necessary for solving structural and technological solutions in sliding pairs of aviation equipment. According to the analysis of the existing current and actual PNC and their preparation, it was established that a friction coefficient of 0.12 can be ensured for the titanium nanocomposite Ti/ND with a content of 0.35% of ND. It is shown that the galvanic application of nanocoatings on steel with a concentration of nanodiamonds in the solution of 8.0 g/l and a current density of 3.0 A/dm2 can provide the hardness of the composite coating with a maximum value of 5.302 GPa and an average grain size of 4 nm. The scientific novelty of the obtained results is as follows: the production technologies and main mechanical properties of PNC when used in sliding pairs of aircraft parts are analyzed. It was found that the existing publications do not provide enough information about the important parameters of the obtained materials, such as heat resistance, moisture resistance, environmental friendliness, and others. Conclusions. It is recommended to test ND with a concentration in the range of 1...3% on tribological parts of aircraft, as well as in sliding pairs with a long life. However, despite the unique mechanical properties of nanocomposites, the regulatory framework for the design of sliding pairs requires additional research and experiments. The given materials can be useful in carrying out theoretical and experimental studies on extending the resource, operation and repair of aircraft and helicopter parts.

Novel intense blue emitting Bi2Zr2O7:Ce3+ nanocomposites insertion into flexible polymer films for anti-counterfeiting, long-term storage fingerprints, and display device applications

The development of multifunctional organic/inorganic hybrid materials for anti-counterfeiting and food packaging applications can be achieved through the use of polymer nanocomposites containing poly(vinyl alcohol) (PVA) and chitosan (CS), as well as Ce3+-activated Bi2Zr2O7 nanocomposites (PCBC NCs). However, synthetic methods for these nanocomposites are often time- and energy-intensive, leading to heterogeneous films that require compatibilizers to disperse the organic matrix's inorganic nanoparticles (NPs). This study used a simple solution casting approach to impregnate the appropriate phosphor sample into PVA-CS (PC) flexible films, resulting in luminous ink for high-security anti-counterfeiting applications. Using this nanocomposite ink offers an even higher level of security, as the prints can be submerged in copper chloride (CuCl2) aqueous solutions to quench the luminous message. The masked fingerprints used for long-term storage (up to 12 months) exhibit stable level 1–3 ridge features with high contrast and sensitivity, which may improve printing quality and performance in the fight against counterfeiting. In addition, a mathematical model implemented in Python-based software was used to investigate the latent fingerprints of level 1–2 ridge features.

Polymer matrix nanocomposites from the ecological aspect in the automotive industry

Meeting the stringent requirements of the automotive industry that the material must meet in terms of price and performance is a serious challenge for engineers. The use of lightweight materials has led to the use of polymer nanocomposites in the automotive industry but has also led to new issues such as the impact on the ecological aspect of the environment. Tests, which are still ongoing, have found improvements in many material properties such as mechanical, thermal, electrical, optical and magnetic. So, on one hand, improved properties and low prices of production and manufacturing have been recorded, on the other hand, there is insufficient research of their impact on the environment, which this paper aims to investigate.

A Brief Review on the High-Energy Electromagnetic Radiation-Shielding Materials Based on Polymer Nanocomposites.

This paper revises the use of polymer nanocomposites to attenuate high-energy electromagnetic radiation (HE-EMR), such as gamma radiation. As known, high-energy radiation produces drastic damage not only in facilities or electronic devices but also to life and the environment. Among the different approaches to attenuate the HE-EMR, we consider the use of compounds with a high atomic number (Z), such as lead, but as known, lead is toxic. Therefore, different works have considered low-toxicity post-transitional metal-based compounds, such as bismuth. Additionally, nanosized particles have shown higher performance to attenuate HE-EMR than those that are micro-sized. On the other hand, materials with π-conjugated systems can also play a role in spreading the energy of electrons ejected as a consequence of the interaction of HE-EMR with matter, preventing the ionization and bond scission of polymers. The different effects produced by the interactions of the matter with HE-EMR are revised. The increase of the shielding properties of lightweight, flexible, and versatile materials such as polymer-based materials can be a contribution for developing technologies to obtain more efficient materials for preventing the damage produced for the HE-EMR in different industries where it is found.

Bacterial Cellulose Network from Kombucha Fermentation Impregnated with Emulsion-Polymerized Poly(methyl methacrylate) to Form Nanocomposite.

The use of bio-based residues is one of the key indicators towards sustainable development goals. In this work, bacterial cellulose, a residue from the fermentation of kombucha tea, was tested as a reinforcing nanofiber network in an emulsion-polymerized poly(methyl methacrylate) (PMMA) matrix. The use of the nanofiber network is facilitating the formation of nanocomposites with well-dispersed nanofibers without using organic solvents or expensive methodologies. Moreover, the bacterial cellulose network structure can serve as a template for the emulsion polymerization of PMMA. The morphology, size, crystallinity, water uptake, and mechanical properties of the kombucha bacterial cellulose (KBC) network were studied. The results showed that KBC nanofibril diameters were ranging between 20–40 nm and the KBC was highly crystalline, >90%. The 3D network was lightweight and porous material, having a density of only 0.014 g/cm3. Furthermore, the compressed KBC network had very good mechanical properties, the E-modulus was 8 GPa, and the tensile strength was 172 MPa. The prepared nanocomposites with a KBC concentration of 8 wt.% were translucent with uniform structure confirmed with scanning electron microscopy study, and furthermore, the KBC network was homogeneously impregnated with the PMMA matrix. The mechanical testing of the nanocomposite showed high stiffness compared to the neat PMMA. A simple simulation of the tensile strength was used to understand the limited strain and strength given by the bacterial cellulose network. The excellent properties of the final material demonstrate the capability of a residue of kombucha fermentation as an excellent nanofiber template for use in polymer nanocomposites.

A Review on Polymer Nanocomposites and Their Effective Applications in Membranes and Adsorbents for Water Treatment and Gas Separation.

Globally, environmental challenges have been recognised as a matter of concern. Among these challenges are the reduced availability and quality of drinking water, and greenhouse gases that give rise to change in climate by entrapping heat, which result in respirational illness from smog and air pollution. Globally, the rate of demand for the use of freshwater has outgrown the rate of population increase; as the rapid growth in town and cities place a huge pressure on neighbouring water resources. Besides, the rapid growth in anthropogenic activities, such as the generation of energy and its conveyance, release carbon dioxide and other greenhouse gases, warming the planet. Polymer nanocomposite has played a significant role in finding solutions to current environmental problems. It has found interest due to its high potential for the reduction of gas emission, and elimination of pollutants, heavy metals, dyes, and oil in wastewater. The revolution of integrating developed novel nanomaterials such as nanoparticles, carbon nanotubes, nanofibers and activated carbon, in polymers, have instigated revitalizing and favourable inventive nanotechnologies for the treatment of wastewater and gas separation. This review discusses the effective employment of polymer nanocomposites for environmental utilizations. Polymer nanocomposite membranes for wastewater treatment and gas separation were reviewed together with their mechanisms. The use of polymer nanocomposites as an adsorbent for toxic metals ions removal and an adsorbent for dye removal were also discussed, together with the mechanism of the adsorption process. Patents in the utilization of innovative polymeric nanocomposite membranes for environmental utilizations were discussed.

Release mechanisms for PA6 nanocomposites under weathering conditions simulating their outdoor uses

The increased use of polymer nanocomposites in different applications could lead to potential nanofiller release into different human and environmental compartments and consequently, increase the exposure of human and environmental species to nanomaterials. This study aims at determining how the inclusion of nanofillers with diverse chemical nature (SiO2, TiO2, ZnO, multiwalled carbon nanotubes and two nano-organoclays) in polyamide 6 composites influences the nanomaterial release during the use of these products. The different nanocomposites were exposed to accelerated ageing processes, simulating outdoor conditions, through irradiation with UV light under a combination of dry-wet cycles. Release monitoring consisted of nanocomposites characterisation, run-off waters collection and released materials quantification and characterisation. The study confirmed that the chemical surface nature of the nanofiller strongly impacts on polymer degradation, in some cases enhancing its protection and in others promoting polyamide hydrolysis and/or photo-degradation processes. Polymer degradation and nanomaterial-polymer compatibility are the main determinants for the release and consequent exposure to nanofillers.

Effect of Water on Polypropylene/Barium Titanate Nanocomposites

In high voltage systems, it is important to have good insulation systems in order to transfer power over a long distance. The use of polymer nanocomposites could make differences in insulation system. However, the presence of water in nanocomposites could negatively affect the performance of nanocomposites as it is found that nanocomposites can absorb more water than unfilled polymers. This study investigated the AC breakdown strength of polypropylene (PP) as polymers blends with 1 wt%, 2 wt% and 5 wt% of barium titanate (BaTiO3) nanofiller and analyzed the effect of water absorption on breakdown strength of polypropylene added with different amount of barium titanate nanofiller. All the samples of nanocomposites were then subjected to water absorption process for certain periods which are 0 days, 10 days, and 20 days to evaluate how much water can be absorbed by the samples and its effect on breakdown strength of nanocomposites. While AC breakdown test was conducted according to standard of American Society for Testing ance Material (ASTM) D149 to correlate the effect of water absorption with the breakdown strength of nanocomposites containing barium titanate.

Strong Reduction in Amplitude of the Interfacial Segmental Dynamics in Polymer Nanocomposites

Despite the wide use of polymer nanocomposites (PNCs) in various applications, our understanding of the microscopic parameters controlling their macroscopic properties remains limited. In this study, we examine the dielectric strength of segmental dynamics, ΔeIL(T) in the interfacial polymer layer surrounding the nanoparticles in PNCs. The presented analysis reveals a significant drop in ΔeIL(T) and its anomalous temperature dependence in the polymer layer adsorbed to nanoparticles. The drop in ΔeIL(T) was observed in all samples regardless of whether segmental relaxation time in the interfacial layer was slower or faster than in the bulk polymer, excluding interpretation of the “dead” layer. We ascribe the observed decrease in the dielectric strength to the restricted amplitude of segmental relaxation in the interfacial/adsorbed layer. Our results provide a new perspective on discussion of dynamics in the interfacial layer in PNCs and thin polymer films, demonstrating that not only segmental relaxation time but also its amplitude can be strongly affected by the interface.

Chemical Surface Modification and Characterization of Carbon Nanostructures Without Shape Damage

Abstract Carbon nanostructures have been extensively studied due to combination of properties they present. With different geometries and reactivities, carbon nanotubes, graphene and fullerene were oxidized and modified with octadecylamine (ODA) in order to decrease van der Waals’s interaction and consequently improve the polymer-carbon nanostructures affinity for use in nanocomposites. Nanostructures were characterized as morphology, chemical structure, molecular conformation and thermal properties. All nanostructures showed results that confirm the modification with ODA, without geometry being altered. Modified nanostructures showed different percentages of ODA: graphene 86%, carbon nanotubes 83% and fullerene 63%. It was attributed to distinct reactivities, shapes and specific surface area available, due to different amounts of reactive terminals obtained before oxidation reactions. However, they showed a lower interfacial interaction, which is highly favorable for use in polymer nanocomposites.

Polymer Nanocomposites for Photocatalytic Applications

In the present comprehensive review we have specifically focused on polymer nanocomposites used as photocatalytic materials in fine organic reactions or in organic pollutants degradation. The selection of the polymer substrates for the immobilization of the active catalyst particles is motivated by several advantages displayed by them, such as: Environmental stability, chemical inertness and resistance to ultraviolet radiations, mechanical stability, low prices and ease availability. Additionally, the use of polymer nanocomposites as photocatalysts offers the possibility of a facile separation and reuse of the materials, eliminating thus the post-treatment separation processes and implicitly reducing the costs of the procedure. This review covers the polymer-based photocatalytic materials containing the most popular inorganic nanoparticles with good catalytic performance under UV or visible light, namely TiO2, ZnO, CeO2, or plasmonic (Ag, Au, Pt, Pd) NPs. The study is mainly targeted on the preparation, photocatalytic activity, strategies directed toward the increase of photocatalytic efficiency under visible light and reuse of the hybrid polymer catalysts.

Improvement of Electrical Insulation in Silicone Rubber by Adding Al2O3

Polymer Nano composite in recent time has shown high improvement in mechanical, chemical and electrical properties. Granting all these, the use of polymer nano-composites has only recently begun starting explorer. In recent times, polymer materials has shown remarkable improvement in electrical insulation because of their numerous advantages in out-door insulation systems because of their negligible weight, better pollution performance, low cost, good dielectric properties with easy processing. In polymer materials, silicone rubber is one of the lead polymer currently used and has high ending properties like high voltage insulator, thermal stability, excellent UV resistance and hydrophobicity. Therefore, Silicone rubber with fillers can overcome few drawbacks such as low strength and insulating properties.Oxides with different properties can help silicone rubber to enhance its properties. Oxides such as alumina, zirconia are being widely used in silicone rubber. Alumina which has strong thermal conductive and compressive strength with good electrical is used in silicone rubber. Here Silicone rubber nano composites are prepared by incorporating Al2O3 nano partic les. Electrical, Chemical properties like NaCl, HCl, and corrosion tests were conducted to know the performance of silicone rubber insulation at pollutant conditions. Dielectric tests were also done to know whether Al2O3 has made any effect with silicone rubber. Tensile strength and Hardness test were carried out to determine mechanical strength of the rubber.

Spall Characterization of EPON 828 Epoxy with Embedded Carbon Nanotubes

The increasing use of polymer nanocomposites in armor applications requires an understanding of how these materials behave at strain-rates relevant to ballistic impacts. Of particular interest is the role of the microstructure on the failure of these materials under dynamic tensile loading. In the present study, plate impact experiments were conducted in order to measure the spall strength of a neat epoxy (EPON 828) and an epoxy–carbon nanotube composite. The addition of pristine carbon nanotubes (CNTs) to the epoxy resulted in a composite material with a lower spall strength than the neat epoxy matrix material. Recovered composite fragments were imaged with a scanning electron microscope. Instances of nanotube pull-out were identified on internal fracture surfaces. The lower spall threshold of the epoxy–CNT composite was attributed to the comparatively weak epoxy–CNT interface, which provides potential sites from which spall failure can favorably nucleate.

Intercalation and Characterization of Kaolinite Amazon to Production Polymer Nanocomposites

Polymer nanocomposites using natural clays such as nanofiller have mechanical properties, flame-retardant, the gas barrier improvement compared to polymers without nanoclay. The aim of this work is intercalated molecules between the clay layers and characterize it with a view to its use in polymer nanocomposites. The kaolinite neat and modified used was characterized by fourier transform spectroscopy (FTIR), X-ray diffraction (XDR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and thermogravimetry (TGA). The results showed that kaolinite can be used as a nanofiller in polymer nanocomposites.

Synthesis and characterization of alginate beads encapsulated zinc oxide nanoparticles for bacteria disinfection in water

The use of polymer nanocomposites as novel materials for water remediation has emerged as a promising alternative for disinfection of bacteria contaminated water. Sodium alginate, a natural biopolymer has been investigated in this study by encapsulating antimicrobial zinc oxide nanoparticles supported bentonite. The confirmation of the alginate nanocomposites was done by use of TEM, SEM-EDS and XRD. The antimicrobial activity of the alginate nanocomposites was investigated by batch studies using surface water and synthetic bacteria contaminated water containing Staphylococcus aureus. The effect of nanocomposite amount and initial bacteria concentration has been studied. The inactivation results indicated that the nanocomposite effectively inactivated bacteria in both the synthetic and surface water. With an amount of 0.5 g of the nanocomposites, no bacteria was observed in the water after 70 min of contact time with initial bacteria concentration of 200 cfu/ml for synthetic water and within a min, no bacteria was observed in the water for surface water. It is worth noting that 200 cfu/ml is the bacteria concentration range in which environmental water is likely to contain. Therefore, the results of this study have indicated that the alginate nanocomposites can be deemed as a potential antimicrobial agent for water disinfection.

PREPARATION AND PROPERTIES OF EXFOLIATED VERMICULITE-POLYAMIDE 6 NANOCOMPOSITE

Ion-exchange treatment of natural vermiculite (VER) with dodecylammonium (DDA) ions and subsequent preparation of a polyamide 6 (PA6) based nanocomposite was conducted to investigate the potential suitability of VER for use in polymer nanocomposites. In order to investigate the ion-exchange behavior, ground VER powder and DDA were treated at 60°C for 12 h, in which time the intercalation reaction was completed. DDA intercalation was rapid and complete for VER even in dilute DDA solution (0.5 mass%) at a low suspension VER concentration of 1 mass%. The VER-PA6 nanocomposite was formed via exfoliation of a DDA modified VER (DDAVER) layer. DDAVER was melt-kneaded with PA6 in a twin-screw extruder at 260°C. The morphology of the nanocomposite was characterized using X-ray diffraction and transmission electron microscopy. Measurements of the mechanical properties and methanol permeability were also carried out. The DDAVER-PA6 nanocomposite exhibits a high degree of VER exfoliation and the rigidity and gas barrier properties also appear to reflect the nanocomposite morphology. Addition of a small amount of DDAVER with 3 mass% sili- cate was sufficient to improve the rigidity, heat resistance and barrier properties of the nanocomposite.

Spectroscopic and Mechanical Properties of Nano Silica Rubber Composite Material

AbstractTo manipulate the mechanical properties of acrylonitrile butadiene rubber (NBR), addition of nano-sized silica on rubberwas performed and nano-silica NBR composite (NSR) materials were fabricated by press molding. The effect of volumefraction of silica in the NSR on the spectroscopic and mechanical properties has been studied.Keywords: NBR, Nano-silica, Volume Fraction, NSR 1. Introduction Polymer nano-composites (NCs) have been a subjectof interest for their mechanical, chemical, and thermalproperties instead of polymers and conventional com-posites materials. Before the use of polymer NCs to var-ious components, such as rubber seals, bearings, andbelts, in industrial materials [1,2] , the accurate analyses oftheir mechanical and chemical properties are necessary.The Charpy impact test is usually adopted to understandof polymer NCs for a long time, the relationshipbetween the stress and the critical energy release ratehas been considered important recently [3-5] .Among various types of polymers, acrylonitrile buta-diene rubber (NBR) is an attractive material system dueto its excellent resistance to organic solvents

Palygorskite/polystyrene nanocomposites via facile in-situ bulk polymerization: Gelation and thermal properties

Novel palygorskite/polystyrene (PLG/PS) nanocomposites were synthesized via the facile in-situ bulk radical polymerization of styrene in the presence of the organo-palygorskite (Org-PLG) nanorods, which was prepared by the modification of the acid-activated palygorskite (A-PLG) nanorods with the functional silane (γ-methacryloxypropyl trimethoxy silane (MPS)). The micro-gels with the Org-PLG nanorods as crosslinker were produced in the PLG/PS nanocomposites regardless of the polymerizing conditions, such as the feeding ratios of the Org-PLG, initiator and N2 atmosphere. Based on the gelation and thermal properties of the PLG/PS nanocomposites, the optimal preparation condition via the in-situ bulk polymerization was achieved and the crosslinking mechanism to the micro-gels was also depicted. This understanding should lead to a better design of clay mineral modifications for use in polymer nanocomposites.