Transparent Nanocomposite Films Research Articles

Copper and nickel hexacyanoferrates/carbon nanotube nanocomposites thin films as high-performance light cathode materials for aqueous sodium-ion batteries

Aqueous rechargeable Na-ion batteries are gaining popularity as an attractive alternative for energy storage systems due to their low cost, wide range of raw material sources, non-flammability, and ultrahigh ionic conductivity. Currently, Because of their three-dimensional open structure, high specific capacity, and inexpensive cost, Prussian blue analogues are being investigated as electrode materials for electrochemistry. In this work, we present an innovative strategy to create novel two-component nanoarchitected thin films that exhibit exceptional performance as cathodes in aqueous sodium-ion batteries (SIBs). By leveraging the versatility of the liquid-liquid interfacial method, we have prepared two distinct transparent nanocomposite films composed of carbon nanotubes and either copper or nickel hexacyanoferrate nanoparticles. The results show that the NiHCF/CNT and CuHCF/CNT deliver a high specific capacity of 152 mA h g−1 and 135 mA h g−1, respectively, at a high current density of 1 A g−1. Moreover, the cells (rGO//NiHCF and rGO//CuHCF) show that the energy density of the battery can reach up to 7.75 Wh kg−1 at a power density of 27.92 W kg−1 for rGO//NiHCF/CNT, while rGO//CuHCF/CNT showed an energy density of 3.67 Wh kg−1 at a power density of 13.21 W kg−1. The results demonstrate that NiHCF/CNT and CuHCF/CNT nanocomposite films provide new insight into the design of high-performance PBA cathodes.

The Critical Role of Ca2+ in Improving the Transparency and Strength of High-Filler-Content Nanocellulose/Montmorillonite Nanocomposite Films.

Strong and transparent nanocellulose/montmorillonite (MMT) nanocomposite films with high filler content (≥50 wt %) are emerging as versatile materials for advanced applications due to their excellent optical, barrier, mechanical, and thermal properties, and environmental friendliness. Nonetheless, these films undergo a notable decline in optical and mechanical properties at high MMT loadings. This study first demonstrates that calcium-ion-induced tactoids are the key factor causing disordered structures in nanocomposite films, leading to the degradation of optical and mechanical properties. We then address this issue by employing a Ca2+ removal strategy─dialysis. Through removing 43% of free Ca2+, simultaneous improvements in both properties are observed. For example, in a nanocomposite film with 70 wt % MMT, light transmittance increases from 75.9 to 91.6%, and the tensile strength rises from 100.4 to 139.4 MPa. This work offers insights into developing strong and transparent nanocomposite films with high MMT contents.

Transparent and High-Refractive-Index Titanium Dioxide/Thermoplastic Polyurethane Nanocomposites.

Transparent nanocomposite films made of surface-modified titanium dioxide nanoparticles and thermoplastic polyurethane are prepared via film casting approach showing enhanced refractive indexes and mechanical properties. Two different sets of composites were prepared up to 37.5 wt % of inorganic nanoparticles with a diameter <15 nm, one set using particles capped only with oleic acid and a second one with a bimodal system layer made of oleic acid and mPEO-5000 as coating agents. All of the composites show significantly enhanced refractive index and mechanical properties than the neat polymeric matrix. The transparency of nanocomposite films shows the excellent dispersion of the inorganic nanoparticles in the polymeric matrix avoiding aggregation and precipitation phenomena. Our study provides a facile and feasible route to produce transparent nanocomposite films with tunable mechanical properties and high refractive indices for various applications.

Large-Size ultrathin mica nanosheets: Reinforcements of biobased PEF polyester

Due to the superior physical properties and high-level alignment of the nanoscale building blocks, assembly of high-quality two-dimensional (2D) nanosheets into macroscopic engineering structure materials can achieve many unexpected performance. Natural mica nanosheets (MNSs) are abundant and with superlative properties, showing huge prospect for engineering structural materials. However, the difficulty of the mass production with large size and high aspect ratio are the current factors that limit this. Inspired by the well-known scotch-tape exfoliation, herein we develop a gummy-tape exfoliation (GTE) method by using liquid oligomers as mediums in ball-milling process to massively produce large-size and ultrathin MNSs. As a confirmation, the obtained MNSs show a record high aspect ratio of ≈1320 and a large actual yield of ∼ 80 %. A transparent biobased aromatic polyester nanocomposite film made of such MNSs and polyethylene furandicarboxylate (PEF) matrix possesses remarkably improved mechanical, barrier properties, and UV-shielding performances at an extremely low filler loading (≤0.5 vol%), making it a novel potential engineering material for packing fields in foods, drugs, and electronic products, etc.

Novel transparent lignin/epoxy resin nanocomposite film development with enhanced UV resistance performance

AbstractThe increased importance of nanostructured lignin exhibits a plethora of multifunctional groups, making it a highly adaptable material basis with significant potential for use in the rapidly expanding composite sector. Initially, lignin nanoparticles (NPs) were incorporated into epoxy networks via an in situ polymerization process where isophorone diamine functioned as a hardener to produce lignin/epoxy resin nanocomposites (lignin@TN). These lignin@TN exhibit promising characteristics, enhancing UV‐blocking efficiency (35.69% at 404 nm with 3.72 wt% lignin) in transparent nanocomposite films while simultaneously improving mechanical properties compared with neat epoxy resin. Adding lignin nanoparticles to epoxy nanocomposites boost up tensile strength by an impressive 24% compared with the pristine epoxy but it affected the glass transition temperature (Tg). After all, this study has opened new possibilities for utilizing renewable, sustainable, and economic lignin feedstocks as a potential ingredient for reinforcing with thermoset polymers like epoxy.

Designing Self-Sustained Hydrogel Electrolytes for Aqueous, Transparent, and Flexible Batteries

The arrival of aqueous sodium-ion batteries has been an essential sustainable advancement in energy storage devices. The use of electrolytes based on polymeric hydrogel is emerging due to the facility in which they can be obtained as film, flexibility, and high ionic conductivity. Additionally, these electrolytes have a dual purpose by acting also as separators. This work deals with the preparation and characterization of hydrogels based on polyvinyl alcohol (PVA), sodium chloride (NaCl), and boric acid (H3BO3) to be used as electrolytes in transparent and flexible aqueous sodium-ion batteries. It was observed that lower amounts of NaCl yielded transparent and conductive gels, while increasing the amount of NaCl yielded translucent samples, due to the non-dissolved NaCl. The preparation, gelation step and electrode deposition were optimized to achieve the maximum transparency and conductivity. Subsequently, the selected electrolyte was applied in symmetric devices based on transparent nanocomposite films as electrodes. These devices demonstrated both high transparency and grand current rates. Furthermore, the performance of the electrolyte was verified in a flexible and symmetrical device, revealing an increased current, indicating improved electrode/electrolyte contact. This observation underscores the efficacy of hydrogels in enhancing device performance, particularly in flexible configurations.

Fabrication and characterization of transparent nanocomposite films based on poly (lactic acid)/polyethylene glycol reinforced with nano glass flake

Developing new biodegradable packaging with superior properties and advanced functionalities is one of the most emerging research areas of interest in food packaging. In this study, PLA/PEG-based nanocomposite films incorporated with different amounts of nano glass flake (NGF) (0, 0.5, 1, and 2 phr) were fabricated via casting solution for applications in food packaging. The ATR-FTIR displayed no chemical interaction between the PLA/PEG-based matrix and NGF particles. The scanning electron microscopy (SEM) observations exhibited a relatively smooth and homogeneous surface without defects. Incorporation of the NGF into the PLA/PEG-based matrix did not affect the color and opacity of the fabricated films. The prepared nanocomposite films were highly transparent and exhibited superior properties such as increased hydrophobicity, appreciable oxygen barrier properties, and enhanced thermal stability. Dynamic mechanical thermal analysis (DMTA) and differential scanning calorimetry (DSC) analysis confirmed the existence of a single glass-transition temperature (Tg) as evidence of miscibility. According to the research results, the PLA/PEG/NGF1 nanocomposite film significantly offered the best overall performance. This work has developed new insight into the potential application of nano glass flakes in food packaging.

Biobased ternary films of thermoplastic starch, bacterial nanocellulose and gallic acid for active food packaging

The use of active packaging technologies and biopolymeric materials are among the emerging trends for implementation of sustainability in the food packaging industry. Thus, herein, bioactive transparent nanocomposite films of thermoplastic starch (TPS) reinforced with bacterial nanocellulose (BNC) (1%, 5% and 10% w/w, relative to starch) and enriched with gallic acid (GA) (1 and 1.5% w/w, relative to starch) were prepared by the solvent casting method. The addition of BNC (≥5% w/w) and GA (1 and 1.5% w/w) enhanced both the mechanical properties (Young's Modulus: 1.2–2.0 GPa vs. 1.0 GPa for TPS; tensile strength: 23–39 MPa vs. 20 MPa for TPS) and the water resistance (moisture absorption and solubility in water) of the nanocomposites. All films are thermally stable up to 125 °C. It was also found that the addition of GA imparted the hydrocolloid TPS-BNC nanocomposites with UV-blocking properties and antioxidant activity (DPPH scavenging activity above 80%). In addition, the film with 10% w/w of BNC nanofibers and 1% w/w of GA had good oxygen barrier properties with a coefficient of permeability of 0.91 ± 0.12 cm3 μm m−2 d−1 kPa−1 and antibacterial activity against the gram-positive Staphylococcus aureus (reduction of about 4.5 log10 colony forming units (CFU) mL−1 after 48 h). This is the first time that antibacterial activity is reported for TPS-BNC nanocomposites. The film with 10% w/w of BNC nanofibers and 1% w/w of GA was further demonstrated to have the ability of delaying the browning and weight loss of packaged fresh cut apple stored at +4 °C for 7 days. All these outcomes are of great relevance for the packaging sector, thus attesting the potential of the developed TPS-BNC-GA nanocomposites as sustainable and eco-friendly film materials for active food packaging.

Orange-red emitting MoO3:Sm3+ transparent nano-composite films for anti-counterfeiting and data secure applications

Poly(vinyl alcohol) (PVA) and chitosan (CS) based nanocomposites (NCs) filled by various weight percent of modified MoO3:Sm3+ (MS) nanoparticles (NPs). For the preparation, folic acid (FA) up to 150 mg were used via ultrasonication method then was cast to thin films. The changes in the structural properties of the prepared samples were examined by X-ray diffraction. FT-IR spectroscopy indicated the possible interactions of the MS NPs with the PVA/CS backbones through the absorption bands. MS NPs were homogeneously dispersed in the polymer matrix at nanoscale. The photoluminescence (PL) emission spectra of PVA/CS-MS NCs excited by 404 nm wavelength, with the key emission peaks centred at ∼ 563, ∼600 and ∼ 647 nm are mainly attributed to transitions from 4G5/2→6H5/2, 4G5/2→6H7/2, 4G5/2→6H9/2 respectively. The powder dusting method was used to visualize the latent fingerprints (LFPs) on various surfaces under 404 nm excitation. Additionally, PVA/CS matrix was masked on the developed fingerprints (FPs) for long term storage. The results clearly indicated that, the level 1–3 ridge features were stable up to 180 days with superior contrast and sensitivity. The optimized phosphor powder is used to fabricate unclonable security ink and brush mode technique was used to mark on various surfaces and exposed to UV 404 nm light. The results revealed that the present phosphor can garner significant interest for the use in personal identification and security encoding.

Promising nanocomposites for food packaging based on cellulose – PCL films reinforced by using ZnO nanoparticles in an ionic liquid

The fact that most composites consist of polluting synthetic materials has prompted a search for biodegradable replacements based on cellulose fibers and polycaprolactone as potential packaging materials. In this work, we developed a green, efficient approach to rendering hydrophobic polycaprolactone (PCL) compatible with hydrophilic cellulose fibers by using an ionic liquid as a nanowelding agent in the presence of zinc oxide nanoparticles (ZnONPs). Transparent biobased nanocomposite films were thus directly obtained by in situ ring-opening polymerization (ROP) of ε-caprolactone (CL) monomers onto the dissolved cellulose matrix by using the ionic liquid 1-ethyl-3-methylimidazolium acetate ([EMIM]Ac). [EMIM]Ac and ZnONPs were efficiently catalyzed ε-caprolactone ROP under mild conditions. Cellulose-grafted PCL nanocomposite films were obtained by adding variable amounts of CL and ZnONPs to the cellulose matrix. The maximum grafting of 40% was achieved by using 5▒wt% ZnONPs and 70% CL. FTIR spectra confirmed the presence of PCL in the nanocomposites. Also, FE-SEM revealed uniform dispersion of ZnONPs and PCL in the regenerated cellulose matrix, and trapping of nanoparticles in nanofibrils after the cellulose matrix was regenerated. X-ray diffraction (XRD) spectra showed a decreased apparent crystallinity and crystallite size. The XRD results also confirmed that the crystal properties of the nanocomposite films and an all-cellulose composite (ACC) were almost identical. The mechanical, barrier and optical properties of the nanocomposite films were significantly better than those of the ACC film by effect of the incorporation of ZnONPs and PCL especially with 5▒wt% ZnONPs and 70% CL). The nanocomposite films exhibited acceptable antioxidant activity and UV-light barrier properties, so they hold promise for used in food packaging. Nanocomposite films are in fact multifunctional materials with the potential for use in cellulose-based food packaging by virtue of their being transparent and bio-based, and possessing very good water vapor and oxygen barrier properties.

Nanoarchitected graphene/copper oxide nanoparticles/MoS2 ternary thin films as highly efficient electrodes for aqueous sodium-ion batteries.

Sodium-ion batteries (SIBs) operating in aqueous electrolyte are an emerging technology that promises to be safer, cheaper, more sustainable and more efficient than their lithium-based counterparts. One of the great challenges associated with this technology is the development of advanced materials with high specific capacity to be used as electrodes. Herein, we describe an ingenious strategy to prepare unprecedented tri-component nanoarchitected thin films with superior performance when applied as anodes in aqueous SIBs. Taking advantage of the broadness and versatility of the liquid-liquid interfacial route, three transparent nanocomposite films comprising graphene, molybdenum sulphide and copper oxide nanoparticles have been prepared. The samples were characterized using several techniques, and the results demonstrated that depending on the specific experimental strategy, different nanoarchitectures are achieved, resulting in different and improved properties. An astonishing capacity of 1377 mA h g-1 at 0.1 A g-1 and a degree of recovery of 100% were observed for the film in which the interactions among the components were optimized. This is among the highest capacity values reported in the literature and demonstrates the potential of these tri-component materials to be used as anodes in aqueous sodium-ion batteries.

Grafting natural nicotinamide on tempo-oxidized cellulose nanofibrils to prepare flexible and transparent nanocomposite films with fascinating mechanical strength and UV shielding performance

Light pollution from ultraviolet (UV) radiation is gaining growing concerns, as the emissions and burning of fossil fuels destroyed the ozone layer. Seeking a solution against skin exposure to excessive radiation is an urgent requirement. In this study, nicotinamide (NA), the main component of vitamin B3, was introduced as a new modifier into Tempo-oxidized cellulose nanofibrils (TOCNFs) together with the physical cross-linking with tannin acid (TA) to improve anti-UV performance of the nanocomposite films. Incorporation of NA into the films presents distinguished UV shielding capability UVB wavelength range from 200 nm to 320 nm (NTA1–5) due to the introduced functional groups like CO and benzene rings. Moreover, mechanical properties were notably enhanced, which overcome the low strength of common nanocellulosic materials. The stress increased from 69.8 MPa to 116.3 MPa, and the toughness can reach 131.58 MJ/m3 by tuning the additional amount of NA. Meanwhile, TGA and DTG analysis demonstrated that the incorporation of amide bonds and TA into the composite films greatly improved the thermal stability. Thus, the proposed materials fabricated from natural biomolecules show great potential in serving as new kinds of UV-resistant products in the application areas of sunscreen, protective clothing, and building materials.

GO induced grain-boundary modification in transparent TiO2-GO nanocomposite thin films: Study by DC bias dependent impedance spectroscopy

Here we present the study on GO induced grain boundary modification of solution-processed transparent TiO2-GO nanocomposite thin films by dc bias dependent impedance spectroscopy. The experimental Nyquist plot obtained from impedance spectra is fitted by an appropriate model electrical circuit comprised of two parallel R-C circuits connected with a series resistance in order to evaluate different contributions arising from core grains and grain boundaries. Variation of relaxation times (τ = RC) with external bias and its modification after GO reinforcement confirms grain boundary modification and its influence on charge transport in nanocomposites.

Surface Modification of ZrO2 Nanoparticles with TEOS to Prepare Transparent ZrO2@SiO2-PDMS Nanocomposite Films with Adjustable Refractive Indices

Here, highly transparent nanocomposite films with an adjustable refractive index were fabricated through stable dispersion of ZrO2 (n = 2.16) nanoparticles (NPs) subjected to surface modification with SiO2 (n = 1.46) in polydimethylsiloxane (PDMS) (n = 1.42) using the Stöber method. ZrO2 NPs (13.7 nm) were synthesized using conventional hydrothermal synthesis, and their surface modification with SiO2 (ZrO2@SiO2 NPs) was controlled by varying the reaction time (3–54 h). The surface modification of the NPs was characterized using Fourier-transform infrared spectroscopy, dynamic light scattering, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy, and ellipsometry. The surface modification was monitored, and the effective layer thickness of SiO2 varied from 0.1 nm to 4.2 nm. The effective refractive index of the ZrO2@SiO2 NPs at λ = 633 nm was gradually reduced from 2.16 to 1.63. The 100 nm nanocomposite film was prepared by spin-coating the dispersion of ZrO2@SiO2 NPs in PDMS on the coverslip. The nanocomposite film prepared using ZrO2@SiO2 NPs with a reaction time of 18 h (ZrO2@SiO2-18h-PDMS) exhibited excellent optical transparency (Taverage = 91.1%), close to the transparency of the coverslip (Taverage = 91.4%) in the visible range, and an adjustable refractive index (n = 1.42–1.60) as the NP content in the film increased from 0 to 50.0 wt%.

Zwitterionic Block Copolymers for the Synthesis and Stabilization of Perovskite Nanocrystals.

Traditional hot injection methods for the preparation of cesium lead halide perovskite nanocrystals (CsPbX3 PNCs, where X=Cl, Br, or I) rely on small molecule surfactants to produce PNCs with cube, plate, or rod-like morphologies. Here, we describe a new method whereby zwitterionic block copolymers are employed as macromolecular ligands in PNC synthesis, affording PNCs with excellent colloidal stability, high photoluminescence quantum yield, and in some cases distinctly non-cubic shapes. The block copolymers used in this study - composed of a poly(n-butyl methacrylate) hydrophobic block and zwitterionic methacrylate hydrophilic blocks - dissolve in useful solvents for PNC growth despite containing large mole percentages of zwitterionic groups. PNCs prepared with block copolymer ligands were found to disperse and retain their fluorescence in a range of polar organic solvents and were amenable to direct integration into optically transparent nanocomposite thin films with high PNC content.

Enhancement of Ultraviolet Light Resistance of Colorless and Transparent Semi-Alicyclic Polyimide Nanocomposite Films via the Incorporation of Hindered Amine Light Stabilizers for Potential Applications in Flexible Optoelectronics.

Optically transparent polymer films with excellent thermal and ultraviolet (UV) resistance have been highly desired in advanced optoelectronic fields, such as flexible substrates for photovoltaic devices. Colorless and transparent polyimide (CPI) films simultaneously possess the good thermal stability and optical transparency. However, conventional CPI films usually suffered from the UV exposure and have to face the deterioration of optical properties during the long-term service in UV environments. In the current work, the commercially available hindered amine light stabilizers (HALS) were tried to be incorporated into the semi-alicyclic CPI matrix with the aim of enhancing the UV exposure stability. For this target, a CPI-0 film was first prepared from hydrogenated pyromellitic dianhydride (HPMDA) and 2,2′-dimethylbenzidine (DMBZ) via a one-step polycondensation procedure. Then, the commercially available HALS were incorporated into the CPI-0 (HPMDA-DMBZ) film matrix to afford four series of CPI/HALS composite films. Experimental results indicated that the Tinuvin® 791 HALS showed the best miscibility with the CPI-0 film matrix and the derived CPI-D series of composite films exhibited the best optical transmittances. The CPI-D nanocomposite films showed apparently enhanced UV exposure stability via incorporation of the 791 additives. For the pristine CPI-0 film, after the UV exposure for 6 h, the optical properties, including the transmittance at the wavelength of 350 nm (T350), lightness (L*), yellow indices (b*), and haze obviously deteriorated with the T350 values from 55.7% to 17.5%, the L* values from 95.12 to 91.38, the b* values from 3.38 to 21.95, and the haze values from 1.46% to 9.33%. However, for the CPI-D-10 film (791: CPI-0 = 1.0 wt%, weight percent), the optical parameters were highly maintained with the T350 values from 61.4% to 53.8%, the L* values from 95.46 to 95.36, the b* values from 1.84 to 1.51, and the haze values from 0.69% to 3.34% under the same UV aging conditions.

Synthesis and characterization of ZnO nanorods-Zn2SiO4 nanoparticles-PMMA nanocomposites for UV-C protection

Nowadays, UV-C is used in a variety of applications, such as disinfection and sterilization of air, surface, and liquids. In particular, its application against the pandemic COVID-19 virus is of great interest. On the other hand, it must be remarked that UV-C is harmful to the eyes, face, head, ears, and skin of engaged employees or personnel but studies on the UV-C range are rare. To the best of our knowledge, studies on zinc silicate as UV-absorber are very rare. In this research, flexible and transparent ZnO nanorods-Zn2SiO4 nanoparticles-PMMA nanocomposite thin films were made for protecting against UV-C radiation. To find the most suitable morphology, the effect of pH variation on the morphology and structural properties of the prepared ZnO–Zn2SiO4 composites were studied. Here we show that the most regular morphology of composites consisting of ZnO nanorods decorated with Zn2SiO4 nanoparticles was obtained at pH 12.5. The UV–vis spectra show that ZnO–Zn2SiO4-PMMA nanocomposite thin films prepared at pH 12.5 exhibit optical transparency in the visible-wavelength region and a prominent UV-C absorbing capability.

Preparation and Characterization of Transparent Polyimide Nanocomposite Films with Potential Applications as Spacecraft Antenna Substrates with Low Dielectric Features and Good Sustainability in Atomic-Oxygen Environments

Optically transparent polyimide (PI) films with good dielectric properties and long-term sustainability in atomic-oxygen (AO) environments have been highly desired as antenna substrates in low earth orbit (LEO) aerospace applications. However, PI substrates with low dielectric constant (low-Dk), low dielectric dissipation factor (low-Df) and high AO resistance have rarely been reported due to the difficulties in achieving both high AO survivability and good dielectric parameters simultaneously. In the present work, an intrinsically low-Dk and low-Df optically transparent PI film matrix, poly[4,4′-(hexafluoroisopropylidene)diphthalic anhydride-co-2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane] (6FPI) was combined with a nanocage trisilanolphenyl polyhedral oligomeric silsesquioxane (TSP-POSS) additive in order to afford novel organic–inorganic nanocomposite films with enhanced AO-resistant properties and reduced dielectric parameters. The derived 6FPI/POSS films exhibited the Dk and Df values as low as 2.52 and 0.006 at the frequency of 1 MHz, respectively. Meanwhile, the composite films showed good AO resistance with the erosion yield as low as 4.0 × 10−25 cm3/atom at the exposure flux of 4.02 × 1020 atom/cm2, which decreased by nearly one order of magnitude compared with the value of 3.0 × 10−24 cm3/atom of the standard PI-ref Kapton® film.

Transparent hierarchical micro-nano structure PTFE-SiO2 nanocomposite thin film with superhydrophobic, self-cleaning and anti-icing properties

Superhydrophobic surfaces are often recommended for anti-icing applications due to their high ability to repel water and reduce ice accumulation and adhesion. In this study, PTFE-SiO2 thin films with different concentrations of silica (0, 1, 2 and 5 g/l) were deposited on the glass substrate by a sol-gel dip coating method. Water contact angle on the samples were measured by a water contact analyzer. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) and field emission scanning electron microscopy (FE-SEM) techniques were used to investigate the chemical bonds formed on the film surface and film surface morphology. The thermal stability of the films was evaluated at different temperatures (from 200 to 500 °C). Also, the stability of the film under ultraviolet radiation was investigated under UV light irradiation. Also, the anti-icing properties of the films were investigated using both simulated static and dynamic methods. Self-cleaning properties of the film were evaluated using iron oxide powder. The water contact angle on the sample with PTFE film without silica nanoparticles is equal to 146°. The water contact angle on the film surface remains constant with increasing amount of the silica nanoparticles from 0 to 1 g/l. By increasing the amount of the silica nanoparticles to 2 g/l d, the contact angle increases to 155°. With increasing the silica nanoparticles amount to 5 g/l, water contact angle decreases. So, PTFE-SiO2 thin film with 2 g/l SiO2 was selected as an optimal thin film. The results of the thermal stability and UV irradiation tests showed that the films were stable up to 400 °C and 16 days of UV radiation, respectively. Indeed, the optimal thin film showed anti-icing and self-cleaning properties.

Development of highly transparent UV‐curable nylon 6 nanofiber‐reinforced polyurethane acrylate nanocomposite coatings for pre‐coated metals

AbstractThe aim of this study is the development of the UV‐curable polyurethane acrylate‐based transparent nanocomposite by using electrospun nylon 6 nanofibers as reinforcement. To accomplish the perfect embedment of nylon 6 nanofibers, over‐coating is the leading advantage on account of the ultrafast wetting and chemical interaction with the UV‐curable PUA matrix system. The remarkable properties of nylon 6 nanofibers offer the use of a very tiny amount of nanofibers as reinforcement in developing nanocomposites, which allowed a significant improvement of the mechanical properties. We developed optically transparent and flexible nanocomposite films and coatings based on casting, electrospinning, and UV‐curing. The reinforcement of nanofibers in the nanocomposites maintains 89%–93% optical transmittance in the visible light range with remarkable enhancement of the tensile strength by 85% for 240 min nanofiber deposition in nanocomposite films. The annexed results generated much consideration and proved that the embedment of nylon 6 nanofibers leads to a wide range of applications for pre‐coated metals. The morphologies of the nanofibers and properties of the thin film composites were also investigated. The potential utilization of nanofibers as a reinforcement and the fabrication of a nanocomposite along with its characterization comparably to the UV‐cured polyurethane acrylate film are also discussed.