Abstract

Introduction

Wastewater in area of focus

Nanotechnology in water purifcation

Nano‑adsorption

Microbial agent

Nanocomposites

Types of nanocomposites

Synthesis modes for nanocomposites

Graphene oxide‑based composites as a disinfectant

Zinc oxide nanocomposites as disinfectant

Copper oxide nanocomposites

Silver/silver oxide nanocomposites

Titanium oxide nanocomposites

Discussion

Conclusion

References

Abstract

     Water is crucial for the existence of life. The world, however, is facing a global water crisis. There are variety of microorganisms, gases and other toxins responsible for water contamination. Various types of nanomaterials exist that have enormous potential to treat contaminated water (water containing metal toxins or specific organic or inorganic impurities) due to their unique properties such as a high surface area and their ability to work effectively even at low concentrations. In recent years, scientists have been giving considerable attention to the application of nanocomposites for water purification, wastewater treatment, microorganism elimination, chemical contaminants, heavy metals removal and so forth. The incorporation of different nanofillers such as carbon nanotubes, graphene oxide, 2D materials, zinc oxide, titanium dioxide, copper and silver nanoparticles into polymeric materials has facilitated important advances, such as suppressing the accumulation of pollutants and foulants, improving the hydrophilicity, increasing the efficiency and improving the mechanical properties. This review discusses leading advances in the development of nanocomposites for antimicrobial and wastewater treatment with the aim of providing an improved understanding of nanocomposites and their applications in antimicrobial and wastewater treatment.

Introduction

     Water is a basic requirement for human life. However, we are far from meeting global requirements for clean water, and this issue will continue to grow over the time (Hillie and Hlophe 2007; Elwakeel et al. 2020b). The demand of clean drinking water is rising as a result of the deterioration of water quality, global climate change and population growth (Tchobanoglous et al. 1991; Elwakeel et al. 2020d). Emissions of organic dyes and heavy metal ions from the paper, leather and textile industries are a serious problem, as they are potentially mutagenic and carcinogenic. To meet environmental requirements, wastewater contaminated with these organic and inorganic species need to be treated before being discharged (Santhosh et al. 2016; Elwakeel et al. 2021). Heavy metals are widely used in various industries for many purposes, including mining and pigment production. Synthetic dyes are also an important type of pollutant, and their sources for water contamination include the textile, pulp and paper, tinting, printing, painting and tanning industries. The removal of dye from such wastewater is a challenging task, as pigments and synthetic dyes are biodegradation-resistant and remain in the environment for a long time. The destruction and handling of organic dyes is therefore an important issue, and a cost-efective method for removing dye substances from wastewater has been developed (Santhosh et al. 2016; Elwakeel et al. 2018).

Conclusion

     This paper explores the existing nanocomposites used to extract heavy metal ions and dyes from wastewater as efective adsorbents. This article addressed recent developments in nanomaterials as economical and environmentally sustainable water purifcation adsorbents. This review highlights fve commonly used nanomaterials/nanoparticles that are used in most existing nanocomposites. In this review, we concluded that TiO2-based nanocomposites have been used for photodegradation activity by most of the researchers in the literature. Silver-based nanocomposites are mostly used for antimicrobial activity. Silver and GO-based nanocomposites were used for the removal of green dye, anionic dye and Cu(II). Copper-based nanocomposites are mostly used for adsorption and photodegradation activity. Zinc oxide nanocomposites are used for adsorption, antimicrobial and photodegradation activity. Finally, we concluded that GO also greatly contributes to the improvement of other materials’ efciency. Further, much needs to be done to control the two-dimensional GO sheets for advanced technologies in the future. There are many challenges and obstacles associated with handling wastewater, and many precautions are required to prevent environmental and health problems. Therefore, new modern wastewater treatment equipment should be versatile, low-cost and commercially efective.

Abstract

1. Introduction

2. Experimental

3. Results and discussion

4. Conclusion

Conflict of Interest

Supplementary Information

References

Abstract

     This study investigates the effect of graphene oxide (GO) on the mechanical and corrosion behavior, antibacterial performance, and cell response of Mg—Zn—Mn (MZM) nanocomposite. MZM/GO nanocomposites with different amounts of GO (i.e., 0.5wt%, 1.0wt%, and 1.5wt%) were fabricated by the semi-powder metallurgy method. The influence of GO on the MZM nanocomposite was analyzed through the hardness, compressive, corrosion, antibacterial, and cytotoxicity tests. The experimental results showed that, with the increase in the amount of GO (0.5wt% and 1.5wt%), the hardness value, compressive strength, and antibacterial performance of the MZM nanocomposite increased, whereas the cell viability and osteogenesis level decreased after the addition of 1.5wt% GO. Moreover, the electrochemical examination results showed that the corrosion behavior of the MZM alloy was significantly enhanced after encapsulation in 0.5wt% GO. In summary, MZM nanocomposites reinforced with GO can be used for implant applications because of their antibacterial performance and mechanical property.

Introduction

     Currently, because magnesium (Mg) alloys have more benefits than common metallic materials, ceramics, and biodegradable polymers, their biomedical applications have been increasing. In terms of mechanical features, metals have higher mechanical strength and fracture toughness than ceramics or polymers; thus, metals are more appropriate for load-bearing usages than ceramics or polymers [1–2]. The density of human cortical bone (1.75 g/cm3 ) is similar to the density of Mg (1.738 g/cm3 ) and Mg alloys (1.75–1.85 g/cm3 ) but lower than the density of biomedical titanium alloy Ti6Al4V (4.47 g/cm3 ) [3–4]. In terms of biocompatibility, certain amounts of Mg ions in the human body are connected with many metabolic reactions and biological mechanisms [5–6]. Mg alloys are suitable orthopedic and cardiovascular implants because further surgery to remove them is not needed [7–8]. However, an important drawback of Mgbased implants is that they do not have good resistance against corrosion in physiological environments [9]. Mechanical strength could be significantly reduced by rapid and uncontrollable corrosion processes, which leads to premature failure [10]. Moreover, the health of patients who have such implants could be at risk because of the evolution of hydrogen gas and alkalinization of the environments close to the interface between implant and tissue [11]. Therefore, to achieve the secure deployment of biomedical devices, the degradation/corrosion rate of Mg alloys needs to be controlled [12]. In this context, several methods, such as alloying, powder metallurgy (PM), and surface modification strategies, have been used in an extensive number of studies that aimed to solve the problem of corrosion in Mg alloys [13–14]. Among the best methods to enhance the corrosion resistance of porous Mg are PM processes, such as mechanical alloying [15–17].

Conclusion

     In this study, using the semi-powder metallurgy method, different contents of GO were embedded in the Mg–Zn–Mn (MZM) matrix to prepare MZM/xGO nanocomposites for orthopedic applications. The corrosion performance and the 24 20 16 12 8 4 0 0 −0.5 −1.0 −1.5 −2.0 Extension / mm MZM/GO Graphene oxide Graphene oxide Graphene oxide Graphene oxide Crack Crack (a) (c) 1.5GO 0.5GO 1GO MZM (b) MZM composite MZM/0.5GO MZM/1GO MZM/1.5GO 49 59 63 64 Compression strength / N 4820 17810 19960 9620 1.12 1.31 1.44 0.72 Force / (10 3 N) Micro hardness, HV Extension / mm Material nanocomposite Fig. 10.    (a) Typical compressive curves and (b) hardness and compressive strength values of the MZM/xGO nanocomposites; (c) schematic diagram of the crack deflection toughening mechanisms of GO in the MZM/xGO nanocomposites. S. Jabbarzare et al., Effect of graphene oxide on the corrosion, mechanical and biological properties of Mg-based … 317 mechanical and biological characteristics of the MZM/xGO nanocomposites were analyzed. The microstructural assessment showed that a uniform distribution was achieved in the MZM/0.5GO and MZM/1GO nanocomposite specimens. However, agglomeration was observed in the MZM/1.5GO nanocomposite specimen. The results showed that the GO content, hardness value, and compressive strength are positively associated. In this context, the MZM/1GO nanocomposite has higher hardness value and compressive strength than the Mg-based nanocomposite without GO. The MZM/ 0.5GO nanocomposite exhibited a nearly comparable corrosion resistance to the MZM/1GO nanocomposite, even though the incorporation of more GO has an unfavorable effect on the Rct value of the MZM matrix. The MTT assay results showed that the MZM/1GO nanocomposite increased the MG63 cell viability and ALP activity, indicating the increasing level of osteogenesis. The results of the analysis of antibacterial activity showed that the MZM/1.5GO nanocomposite had a noticeable effect on antibacterial effectiveness toward bacteria, including Salmonella–Shigella and Klebsiella pneumoniae. In summary, the results indicate the possibility of utilizing the MZM/1GO nanocomposite for implant applications with effective anti-infection characteristics.

Abstract

INTRODUCTION

COMPUTATIONAL METHODS

DPD Method

Drift-diffusion Model

RESULTS AND DISCUSSION

One-step Quench

Two-step Quench

Comparison with Existing Experimental Observations

CONCLUSIONS

REFERENCES

Abstract

     The mixing morphology control plays a crucial role in photovoltaic power generation, yet this specific effect on device performances remains elusive. Here, we employed computational approaches to delineate the photovoltaic properties of layered heterojunction polymer solar cells with tunable mixing morphologies. One-step quench and two-step quench strategies were proposed to adjust the mixing morphology by thermodynamic and kinetic effects. The computation for the one-step quench revealed that modulating interfacial widths and interfacial roughness could significantly promote the photovoltaic performance of layered heterojunction polymer solar cells. The two-step quench can provide a buffer at a lower temperature before the kinetic quenching, leading to the formation of small-length-scale islands connected to the interface and a further increase in photovoltaic performance. Our discoveries are supported by recent experimental evidence and are anticipated to guide the design of photovoltaic materials with optimal performance.

Introduction

     Polymer solar cells (PSCs) are a kind of potential clean-energy technology, which holds promise for manufacturing lightweight and highly flexible devices such as portable electronic products and building-integrated photovoltaics.[1−5] Although the power conversion efficiency was dramatically improved recently, it has not yet broken through the requirements of commercial markets due to the limitation on the mechanism of charge carrier generation and transport.[6,7] To date, a considerable effort has been devoted to creating novel π-conjugated polymers to improve photovoltaic performance. In contrast, understanding the morphology effect on PSC performance and formulating basic rules that guide morphology optimization need to be further enhanced.

     Optimizing the morphology is indispensable for the successful preparation of PSCs with outstanding performance.[8−12] The PSC performance can be quantitatively correlated with phase purity and Flory-Huggins parameters.[13] Insufficient phase separation in PSCs can lead to performance deteriorations. However, a larger repulsion between donors and acceptors can lead to over-purification of mixed domains and decreased PSC performance.[14] For example, Ade et al. observed that the average power conversion efficiency shows a substantial drop as the composition of the amorphous mixed domains is below the percolation threshold.[15] Ye et al. recently found that such a problem can be resolved by kinetically quenching the mixed domains to an optimal composition close to the percolation threshold.[16] Despite this, fundamental guidelines are still required to optimize PSC performances with optimal mixing morphologies. Combining thermodynamic effects and kinetic controls can assist the design of heterojunctions with varied mixing morphologies.[16] The thermodynamics can drive the phase separation of donors and acceptors in PSCs, and the quench by kinetic control can “lock-in” instantaneous phase-separated morphologies. Recent attention has been paid to the stability of such mixing morphologies.[17−20] However, little is known about the kinetic route to control mixing morphologies and the influence of mixing morphologies on PSC performances. Quantifying the impact of mixing morphology on device performance by developing kinetic control rules is the key to optimizing the heterojunction structure and promoting power conversion efficiency.

Conclusion

     The DPD method, coupled with the drift-diffusion model, was employed to study the mixing morphology effect on the photovoltaic performance of layered heterojunction PSCs. We performed an in silico layer inter-diffusion experiment and designed two quench approaches to regulating the mixing morphology of layered heterojunctions, that is, one-step quench and two-step quench. In the one-step quench, the layered heterojunction with intermediate interfacial width exhibits an optimal photovoltaic performance. We further enhanced the power conversion efficiency of the layered heterojunction by modulating the mixing morphology with a two-step quench method. We discovered that the interfacial width, interfacial roughness, and small-length-scale island structures formed within acceptor- and donor-rich domains combinedly affect the power conversion efficiency. Our work delineates the effect of quenching processes on photovoltaic performance, which could be beneficial to the design and quantitative optimization of active layers.

Abstract

     Two dimensional nanomaterials, such as graphene and MXene, have been widely used to fabricate high performance nanocomposite films owing to their unique structure and excellent physiochemical properties, showing enormous potential applications in many areas. However, the existing voids and wrinkling in the nanocomposite films inevitably impedes realizing the high performance of the nanocomposite films during the assembly process of graphene and MXene nanosheets. Nacre provides an inspiration for fabricating high performance graphene and MXene nanocomposite films through constructing a high alignment structure and strong interface interactions. In this review, we summarize the preparation approaches of graphene and MXene nanocomposite films and discuss the mechanical properties. Then, several effective strategies for assembling graphene and MXene nanosheets have been concluded and discussed. Meanwhile, we also summarize and discuss the applications of graphene and MXene nanocomposite films including electromagnetic interference (EMI) shielding and thermal management. Finally, outlooks and challenges are proposed to promote their progress and applications in the future.

Introduction

     Since the first discovery of graphene in 2004, graphene has gradually aroused widespread attention [1]. Due to the outstanding mechanical, electrical and thermal properties, graphene has been applied in flexible electronic devices, aerospace and thermal management fields in the past decade [2], [3], [4], [5], [6]. For instance, the single-layer graphene has a Young’s modulus of 1.0 TPa [7] and a superhigh thermal conductivity of about 5300 W/mK [8] at room temperature, demonstrating enormous practical potentiality in the above mentioned fields. Before realizing these applications, it is crucial to assemble graphene nanosheets into high performance graphene nanocomposites including one dimensional (1D) fiber, two dimensional (2D) film and three dimensional (3D) bulk. Especially, high performance graphene nanocomposite films have gained enormous attention. However, it is difficult to achieve high performance nanocomposite films due to weak interaction between adjacent graphene nanosheets. Graphene oxide (GO) is a usual precursor for obtaining graphene with plentiful surface terminating groups, which can easily interact with various materials for preparing nanocomposite films [9,10]. Meanwhile, in recent years, MXene, a novel two dimensional (2D) materials, shows promising electrical and thermal properties, which shows promising application in aerospace field [11], [12], [13], [14], [15], [16]. Indeed, compared with graphene, the intrinsic mechanical and thermal conductivity properties and stabilities of MXene is relatively poor. Furthermore, the easily oxidizable characteristics and thermal vulnerability of MXene may restrict its practical applications. However, compared with graphene, MXene has plentiful surface functional groups, which is an ideal building block for fabricating nanocomposite films without chemical modification any more.

Summary and outlook

     In the past several years, two dimensional materials such as graphene and MXene have been widely studied owing to the excellent physiochemical properties. In this review, we have focused on the preparation methods, assembling strategies and mechanical properties of graphene and MXene nanocomposite films. Moreover, we have also discussed the applications of obtained graphene and MXene nanocomposite films such as EMI shielding and thermal conductivity. Various methods such as VAF, blade coating, drop casting and LbL have been used to prepare high performance graphene and MXene nanocomposite films. However, as aforementioned, the existing voids and wrinkling are harmful for the mechanical properties of graphene and MXene nanocomposite films. Hence, several strategies for fabricating high performance graphene and MXene nanocomposite films are proposed.

Abstract

I. INTRODUCTION

II. EXPERIMENTAL DETAILS

III. RESULTS

IV. DISCUSSION

V. CONCLUSION

REFERENCES

Abstract

     Nanocomposites have been developed as the third-generation insulating materials. This article introduces the crosslinked polyethylene (XLPE) nanocomposite dielectric doped with a small amount of nano-hexagonal boron nitride ( h -BN), which exhibits excellent insulation properties under high dc voltage. The test results show that XLPE/ h -BN nanocomposites possess significant improvements in dc breakdown strength and 0.1 wt% nano h -BN doping can actually increase the dc breakdown strength by 39%. The space charge properties of the XLPE/ h -BN obtained by the pulsed electro-acoustic (PEA) measurements and the direct current integrated charge [DCIC- Q(t) ] measurements show that the positive homocharge injection under dc voltage is obviously suppressed, and the electrical conductivity under relatively high electric field decreases. The thermally stimulated current results show that the nano h -BN doping introduces only deep charge traps (above 1 eV) to the XLPE matrix. The trap energy is deeper than that of the original traps, and this is the main factor leading to the improvement of the dc insulation properties. Besides, the doping of h -BN does not introduce impurities or change the crystallinity of XLPE. This article presents the novel XLPE/ h -BN nanocomposites with excellent dc insulation properties and indicates the large potential of the nano h -BN-doped insulation materials.

Introduction

     NANOCOMPOSITES have excellent dielectric properties and have become the third-generation insulating materials [1]. Nano-doping can improve corona resistance and electrical tree characteristics as well as regulate dielectric properties of the polymer matrix. More importantly, the dc insulation properties can be enhanced to various degrees by inorganic nanoparticle doping, such as the suppression of the charge injection and transportation, as well as the increase of the breakdown strength. With the construction of high-voltage direct current (HVDC) transmission line in a large scale, the power industries have proposed stricter requirements on the dc insulation performance of insulating materials. Therefore,nanocomposite dielectrics may be more suitable for dc insulation systems in the future, and nanocomposite materials with higher insulation performance need to be continuously developed. For example, crosslinked polyethylene (XLPE)- based nanocomposites are expected to be used in the new generation of HVDC cable.

Conclusion

     The XLPE/h-BN nanocomposite with high dc breakdown strength and suppressed charge injection features were introduced in this study. It is useful to reach the conclusions as follows.

     1) XLPE/h-BN nanocomposite samples with loading content ranging from 0.1 to 3 wt% were prepared successfully. The dc Eb of the nanocomposite sample shows at most a 39% increase under 0.1 wt% loading.

     2) The effect of h-BN doping on the charge trap characteristics of XLPE is a significant increase in the density of deep traps, and this is the main cause for the improvement of dc insulation properties.

Abstract

     Synthesis and characterization of new polybutadiene-based polyurethane, graphene quantum dot-MnO2 nanoparticles, and relative nanocomposites were set as the aim of current artwork. For this purpose, a one-pot polymerization approach was employed in preparation of polyurethane through the reaction of amine polyol and toluene diisocyanate (TDI) in presence of DBTDL catalyst. Nanocomposites were synthesized using 1 to 3 incorporation percent of graphene quantum dot-MnO2 nanoparticles in polymer matrix. 1H-NMR and FT-IR spectroscopies confirmed successful synthesis of reaction products including graphene quantum dot-MnO2, polyurethane, and nanocomposites. UV-vis and PL spectrophotometry techniques were applied for achieving optical information of samples. Optical properties of nanocomposites were reserved properly with no great quenching. Thermal stabilities, degradation rates, and thermal characteristics of polyurethane and nanocomposites were investigated using TGA/DTG and DSC analysis. Thermal stability showed direct relationship to nanoparticle content, and 3%wt nanocomposite showed improved thermal behaviour in comparison with pure PU. SEM, XRD, and AFM techniques proved successful nanocomposite synthesis with detecting nanoparticle species and fine nanoparticle dispersion with improved topographic and morphologic characteristics making GQD-MnO2 polyurethane nanocomposites a good candidate for using in optical active and thermal stable coatings.

Introduction

     At a time when socioenvironmental problems of polluting industries are the focus of legislators, the general trend is toward the production of new products from recycled materials, especially waste materials. In the case of polybutadiene, because of most usage in tire production in crosslinked form with sulfur or carbon dioxide, it does not seem so reasonable to pay attention on polybutadiene recycling, at least until recognition of successful separation approaches. However, crude polybutadiene itself faced some issues of processability like high molecular weight, high viscosity, low solubility, and high molding that can be solved for usage in wide speared areas with chain modification [1–4].

      Based on a common belief in green chemistry, it is much more beneficial to produce high-performance polymers form existing low-use ones than new starting monomers. With this respect, chemical modification of polybutadiene chain could make possible goals like raising polymer applications, introducing high-performance polymers, and preventing overproduction of new polymers with optimistic perspective to polybutadiene recycling [5, 6].

     Double-bond scission of polybutadiene chain usually occurs through chain oxidation using hydrogen peroxide, metachloroperbenzoic acid, and dimethyl dioxirane. The molecular weight could be engineered by peracid/double-bond unit ratio [7, 8]. Carbonyl functionalized polybutadiene derived from chain cutting down process is an attractive procedure for polyurea and polyurethane synthesis [9, 10].

Conclusion

     At the beginning of this research, graphene quantum dot was successfully prepared by hydrothermal method and coprecipitation approach in order to have GQD-MnO2 nanoparticle synthesis. GQD and GQD-MnO2 nanoparticle accurate synthesis approved by FT-IR spectroscopy, and optical properties of nanoparticles were investigated with UV-vis and PL techniques. In the following, PU-GQD-MnO2 nanocomposite was prepared through an in situ polymerization reaction of synthesized polyol and TDI diisocyanate in presence of different GQD-MnO2 nanoparticle percent. PU-GQD-MnO2 nanocomposite synthesis was confirmed using FT-IR technique. Also, it was resulted from UV-vis and PL analysis that nanocomposites excellently reserved their optical characteristics. Thermal property improvement of nanocomposites was observed using TGA/DTG and DSC methods. Finally, SEM, XRD, and AFM investigations resulted satisfying nanocomposite synthesis, fine nanoparticle distribution, and morphologic and topographic property improvement in nanocomposites in comparison with pure PU.

Highlights

Abstract

Graphical abstract

Keywords

1. Introduction

2. Experimental

3. Results and discussion

4. Conclusions

Declaration of Competing Interest

Acknowledgement

Declaration of Competing Interest

Data Availability

Appendix A. Supplementary material

References

Abstract

Ring-opening polymerization of benzoxazine monomers is a complex process and various chemical structures including N,O-acetal structures, phenolic Mannich structures and arylamine Mannich structures are formed in polybenzoxazines. To understand the polymerization mechanism, the effects of temperature, time and solvent polarity on the polymerization routes, chemical structures and thermal properties were studied. It was discovered that the N,O-acetal structures and the phenoxy structures can be obtained in a low-polarity solvent like dichloromethane at low temperature (−20 °C) with the aid of PCl5, while the arylamine Mannich structures can be readily generated in polar solvent like N,N-Dimethylformamide at high temperature (>80 °C) in the presence of PCl5. However, the phenolic Mannich structures can be directly formed at high temperature (>180 °C) without any catalysts. Upon prolonging the reaction time or elevating the temperature, the phenoxy structures easily rearranged into the N,O-acetal structures or the arylamine Mannich structures. Further increasing the temperature will cause the arylamine Mannich structures to rearrange into the phenolic Mannich structures and even the phenolic methylene structures. Therefore, both phenoxy structures and N,O-acetal structures showed poor thermal stability; while the arylamine Mannich structures possessed lower initial decomposition temperature but higher char yield compared with the phenolic Mannich structures because of the formation of thermally unstable iminium ions and the anchoring of dangling aniline moieties.

1. Introduction

Polybenzoxazines (PBzs) are formed by the ring-opening polymerization (ROP) of nitrogen and oxygen containing six-membered heterocyclic compounds, 3,4-dihydro-2H-1,3-benzoxazines. They are labeled as a kind of new high-performance thermosetting resins that possess good properties similar to or even higher than phenolic resins and satisfactory processability resembling epoxy resins [1–6]. Polybenzoxazines have aroused high research enthusiasm in academic communities and drawn much attention from industries because of their well-known merits: high strength, high modulus, good thermal stability, flame retardance, good dielectric properties, good dimensional stability, low water uptake, outstanding processability and tremendous design flexibility [7–12]. More recently, polybenzoxaiznes have found many functional applications such as shape memory, self-healing, catalyst support, pollution treatment, super capacitor, CO2 absorption and corrosion prevention [13–19]. Additionally, polybenzoxazines are of great potential in the future application as the fossil resources are decreasing rapidly but the amines and phenols that can be used to synthesize benzoxazine monomers are abundant and reproducible in nature [20–24].

Abstract

Keywords

1. Introduction

2. Experimental methods

3. Results and discussion

4. Conclusions

Declaration of Competing Interest

Acknowledgements

References

Further Reading

Abstract

Strontium silicate nanoparticles were filled in the organic matrix of poly ethylene glycol, polyvinyl alcohol and polyvinyl pyrrolidone polymers. Different weight percentages were selected for the preparation of thin films on the glass substrate using spin coating technique. Prepared polymer nanocomposite films were characterized for their structural analysis and compositional details using powder X-ray diffraction. Amorphous polymer films with intense diffraction peaks at around 43.8° and 73° exhibited the crystalline phase when doped with strontium silicate in polymer blend matrix. Structural information shows the stable existence of crystalline nanoparticles in the polymer matrix. Dielectric and electrical properties of these samples were studied in the frequency range from 100 Hz to 5500 Hz. Dielectric constant decreased with increase in frequency and changed to different values based on the loading of different weight percentage of nanoparticles. With increase in frequency, the dipolar ordering of polymer-polymer decreased and strengthens the polymer-nanoparticles interaction. Polyvinyl alcohol with 3- wt% of poly ethylene glycol showed the low dielectric constant and dielectric loss as less than 0.03 confirms their improved dielectric properties. Hence, this composition can be used as a better insulating polymeric nanodielectric material which finds application in packaging of nanoscale electronic devises to have better electromagnetic shielding.

1. Introduction

There is a huge demand for the Multifunctional materials to meet the fast growing technological needs [1–7] Silicates (SiO2) based nanomaterials (NMs) [8–10] have showed better role in the fields of optoelectronics [11,12], electrical insulation [13,14], advance battery [15,16], and fuel cells [17] applications because of their physical and chemical stability. Further, silicates are cheap and available in enormous; further in nano-regime, different properties exhibited were because of increased surface to volume ratio and the quantum confinement effects. Because of their ability to convert near IR-light into strong visible light [18], they can be used in phosphor based lamps [19], Solar cells [20], Biological imaging and Medical-Dosimetry [21]. Thin films of nanocomposites (NCs) blended with both organic and inorganic compounds are in demand for the effective insulation of small-scale devices during packaging. Inorganic and organic materials based polymer nanocomposite (PNC) films where the polymer matrix filled with NMs significantly changes the strength, morphology etc helps in tailoring the various requirements in the fields of automobile, coatings, packaging materials, electronics and optical devices, aerospace, EMI shielding, drug delivery, sensors, medical and consumer devices etc. [22].

Highlights

Abstract

Keywords

1. Introduction

2. Experimental details

3. Results and discussion

4. Health hazards of ethylene acrylic acid co-polymer

5. Conclusion

Declaration of Competing Interest

Acknowledgements

References

Abstract

Bleached cotton fabric and a water-based polymer coating solution made from ethylene acrylic acid co-polymer which is multifunctional polymer material is used in this experimental study to increase the bending and thermal properties of cotton fabrics. Roller coating and Exhaust methods is used to apply ethylene acrylic acid co-polymer solution on the cotton fabric surface. The coated fabric surface is then cured and dried at a temperature of 60–90 °C using a laboratory oven. The developed fabric samples are then taken for testing for its bending and thermal properties using a fabric stiffness tester and DSC thermal analyzer. The chemical composition and its chemical group finger print analysis is also ascertained using FTIR spectra. The fabric stiffness results of coated fabrics show increased bending properties and the thermal property results from DSC and plotted graphs prove its robustness and resistance to heat. However, Roller coating method seems to be more efficient than exhaust method with respect to the application method employed for coating ethylene acrylic acid co-polymer.

1. Introduction

A water-based polymer coating solution, namely ethylene acrylic acid co-polymer which is multifunctional in nature is coated on bleached cotton fabric with an objective to enhance its bending and thermal properties in this study. The bleached cotton fabric is coated with ethylene acrylic acid by padding and exhaust bath process. In this experimental study, small soft rollers are used for padding the cotton fabrics using ethylene acrylic acid solution. Ethylene acrylic acid is multifunctional co-polymer and is mainly used for textile fabric coatings and many other applications which are of medicinal value, including packaging substrates. This liquid forms a thin film and binds uniformly to the substrate when applied on the surface externally. The liquid also finds many applications in cosmetics and commercial polymer thin film products. The liquid is colorless, with no foul odor and hence is used in many textiles and non-woven textiles. The solution has excellent sealing, adhesion properties coupled with its flexibility and special hardness [1].

Coating formulation and its application on fabrics is a complicated process. Many chemicals and polymer additives are used for coating, since adhesion and durability properties are also important for a coated fabrics. The quality of coating is also determined by the coating method and machinery used for coating. There are many techniques of coating that are used in finishing process. Some of them are done using knife-over-roller method, particularly used for polymer coatings that are solvent based, dip-coating for variety of water-based polymers and fabric treatments [11,12,18]. The chemical formulations are based on the functional properties that is desired and the level of ethylene acrylic acid is also determined keeping the health hazard parameters that ethylene acrylic acid can cause to human skin [13,14].

Abstract

Keywords

1. Introduction

2. Polymeric materials used in AM industry

3. Drug delivery

4. Automotive industry

5. Fashion and fabric industry

6. Impact of using polymeric materials

7. Conclusion

CRediT authorship contribution statement

Declaration of Competing Interest

References

Abstract

Polymers are the greatest innovation of the millennium. Due to their low price, ease of manufacture, resistance to water and versatility, polymers have several applications in different domestic and industrial sectors. Digital fabrication technology which is also referred to as 3D printing or additive Manufacturing (AM) is used for creating physical components from a geometrical representation by step-by-step addition of materials. This review paper elaborates on the use of polymers for Rapid Manufacturing. One such material used is Shape Memory Polymers that have been analyzed as Smart Materials (4D Printing Materials). Polymers such as Thermoplastics, elastomers, thermosets, and polymers with integrated fillers, bio-polymers, and polymers blended with biological materials come under the range of other polymeric materials used in AM. The quality evaluations that are performed are based on mechanical properties, part density and temperature stability. Polycarbonates (PC), acrylonitrile butadiene styrene (ABS), polyether-ester ketone (PEEK), polyetherimide (ULTEM) and Nylon are usually utilized polymers in measures which need thermoplastics, or plastics treated by warming to a semi-fluid state and near the softening point.

1. Introduction

Additive manufacturing (AM) is basically 3D printing. Rather than simply using conventional machining techniques which include wastage of materials by removing unwanted fragments, additive manufacturing causes fusion of materials to bind them and create objects. It is comparatively a flexible technology that subtractive manufacturing. Since technology is advancing day by day, new materials are being created to have the right properties that can be applied to the right functions. This review paper mainly focuses on the characteristics of polymeric materials that had been produced and used by the AM industry and the impact on the market of AM. Since several kinds of polymeric materials are available, the manufacturer of the product would prefer the polymer with the optimum conditions for the required purpose. Mechanical properties for example, optimum strength for manufacturing and prototyping is required.

High elasticity is required for garment industry. A high thermal resistivity is required for insulation. Use of light weight polymers are for aerospace applications. Greater amount of ductility is required for wiring and circuitries. Increased toughness is required for supporting materials. An optimum melting point is essential for temperature-dependent environmental factors that are experienced by the polymeric substance used. A proper amount of flexibility is required for better portability of the material. A property called Shape memory has been exhibited by certain polymeric materials which have been discussed in this review which can be used for bridge structures and heat exchangers. Degradability of a material for an allocated period of time is required for the extended use of the material considering fatigue strength of the material. Chemical resistance is an important factor needed for manufacturing of apparatus in chemical industries

Abstract

Keywords

1. Introduction

2. Filler materials

3. Thermal properties of polymer composites

4. Summary

CRediT authorship contribution statement

Declaration of Competing Interest

References

Abstract

Polymer composites are commonly used in industry and are used in various fields such as the aircraft industry, automobile industry, electronic industry and packaging industry, etc. due to their diverse versatility, low cost, light weight, and outstanding chemical consistency. For new technologies, especially in aerospace and aeronautics, thermal properties have become a significant parameter. A reference to a number of research studies is made in this paper and the role of fillers in polymers is studied. The main purpose of this analysis is to identify any possible patterns that control and dictate the thermal properties in polymeric composites.

1. Introduction

There is an increasing demand and development in the field of material science since the last two decades and to fit the requirements of the out-dated products available in the market, material scientists have evolved the polymer composites to outperform their original functions that is being rigid and not buckling. Polymer composite has a large variety of industrial applications due to its many desirable properties ranging from high thermal conductivity to excellent chemical resistance. Polymer composites are mostly anisotropic in nature, these results in them having good mechanical, electrical and thermal properties. Compared to isotropic materials composite materials are much more effective and efficient.

There are many conventional filler materials that are using as a filler material in polymer composites for different applications [1–5]. The ever-alarming concern about the environment can also be put to rest by using the construction, industrial and animal waste as filler which is reinforced with the polymer matrix and enhances the mechanical, physical and thermal properties. However, epoxy polymeric composite despite having so many industrial applications, possess poor mechanical properties. Silica is one of the most ideal inorganic compounds that can be used as reinforcement material along with other inorganic materials. Research also indicates that plant fibres are often used as fillers because of their renewability and high availability. The main sources of natural fibres are both inexhaustible and nonsustainable for example sisal, palm oil and flax. These are then used to make composite material.

Presently the composites that are used in thermal fillers do not provide any electrical properties. Carbon Nanotubes (CNTs) and Graphene Nanotubes (GNTs) have excellent mechanical, thermal and electrical properties. CNTs and GNTs have a strong lattice which gives them good physical and thermal properties [6–8].

With these polymer composite materials integrating into the electronics industry, the developments in thermal properties, especially thermal dissipation heavily influences the performance, reliability and lifetime of these devices. Hence thermal conductivity of these polymer composite materials plays a huge role in a lot of industries. Exhaust heat affects the functioning and the properties of the equipment. A good thermal management system is necessary to protect the equipment from any heat related damages