Nylon Film Research Articles

Highly durable direct-current power generation in polarity-controlled and soft-triggered rotational triboelectric nanogenerator

While the sliding-mode triboelectric nanogenerators (TENGs) have demonstrated one of the most efficient rotational energy harvesting devices, alternating-current (AC) generation and wear-off have been a long-standing bottleneck for practical applications. Here, we developed a polarity-controlled and soft-triggered (P-S) TENG for highly efficient and durable direct-current (DC) power generation. The P-S TENG consists of polytetrafluoroethylene (PTFE), nylon, and Cu films for triboelectrification, as well as another Cu film for charge-delivering electrode. The PTFE and nylon films were alternately attached to the outer acrylic cylinder, and four-segmented Cu films were attached to the inner acrylic cylinder. The P-S TENG generated a power-density of 0.32 mW/cm2, which was 4-fold and 32-fold larger than that of paired alternate and single polarity TENG, respectively. Remarkably, the DC output of P-S TENG remained nearly constant, despite 372,000 rotations, which sharply contrasted with the substantial power decrease (47%) in hard-triggered TENG. This work provides an important advancement in a rotational TENG with high DC power generation and long-term durability.

A buckling-sheet ring oscillator for electronics-free, multimodal locomotion.

Locomotion of soft robots typically relies on control of multiple inflatable actuators by electronic computers and hard valves. Soft pneumatic oscillators can reduce the demand on controllers by generating complex movements required for locomotion from a single, constant input pressure, but either have been constrained to low rates of flow of air or have required complex fabrication processes. Here, we describe a pneumatic oscillator fabricated from flexible, but inextensible, sheets that provides high rates of airflow for practical locomotion by combining three instabilities: out-of-plane buckling of the sheets, kinking of tubing attached to the sheets, and a system-level instability resulting from connection of an odd number of pneumatic inverters made from these sheets in a loop. This device, which we call a "buckling-sheet ring oscillator" (BRO), directly generates movement from its own interaction with its surroundings and consists only of readily available materials assembled in a simple process-specifically, stacking acetate sheets, nylon film, and double-sided tape, and attaching an elastomeric tube. A device incorporating a BRO is capable of both translational and rotational motion over varied terrain (even without a tether) and can climb upward against gravity and downward against the buoyant force encountered under water.

Multi-cylinder-based hybridized electromagnetic-triboelectric nanogenerator harvesting multiple fluid energy for self-powered pipeline leakage monitoring and anticorrosion protection

With the continuous development of human society and urban construction, exploring sustainable power sources of monitor and protection systems for city’s infrastructure is becoming more and more urgent. Scavenging ambient fluid flow energy to efficiently and conveniently power electric devices has potential applications for pipeline systems, especially in remote areas. Here, a multi-cylinder-based hybridized electromagnetic-triboelectric nanogenerator (MCNG) is reported to harvest two types of fluid energy at the same time to double the working frequency of the hybrid NG. The introduction of Nylon film effectively improved the durability and output performance. And the structure to transmit external mechanical through magnetic coupling is easy to packaging and assembly, which provides a stable inner environment. Moreover, the hybrid nanogenerator was demonstrated to effectively harvest energy from wind and water flow to power 1075 LEDs and a temperature sensor. Furthermore, a self-powered wireless pipeline leakage monitoring system and a self-powered cathodic protection system based on the MCNG are developed and illustrated. This work provides a prospective strategy for hybrid nanogenerator to improve working frequency and output stability for practical applications.

A clover shaped triboelectric nanogenerator for self-powered grip strength test system

ABSTRACT Recently, many researchers have paid attention to triboelectric nanogenerators (TENGs) to harvest mechanical energy. Thus, a clover-shaped triboelectric nanogenerator (C-TENG) was designed to obtain mechanical vibration energy and convert them into electricity. The polytetrafluoroethylene (PTFE) film and nylon film act as the triboelectric layers, and the plastic sheet serves as the supporting structure. The maximum output power of a C-TENG can arrive at 453.75 µW. In addition, the C-TENG can play the role of a self-powered sensor for reflecting handgrip strength. This design can promote the development of TENGs in mechanical energy harvesting and self-powered human sports sensors.

Deterioration behavior of aluminum pouch film used as packaging materials for pouch-type lithium-ion batteries

Pouch-type lithium-ion batteries are packed into an aluminum pouch film (Al-Pouch). They are used as power sources for large-scale energy storage systems or electric vehicles because of their attractive features. However, the packaging materials of Al-pouch are prone to contamination from electrolyte containing lithium salt during the electrolyte injection process, a key part of their manufacturing process. This electrolyte contamination can be fatal to the long-term reliability or durability of pouch-type LiBs. Here, therefore, we study of how Al-pouch are damaged by electrolyte contamination; understanding this mechanism is critical for ensuring the long-term reliability and durability of pouch-type LiBs. We find that the nylon film comprising the outer layer of Al-pouch is damaged when it reacts with an electrolyte containing lithium salt in the presence of atmospheric moisture. This leads to cracking, followed by nylon locally peeling off from the Al-pouch. This peeling exposes the underlying thin aluminum film that comprises the middle layer of Al-pouch. Once partially exposed to the atmosphere, severe pitting corrosion occurs on the thin aluminum film. High volumes of moisture to easily penetrate pouch-type LiBs through these corroded pits, showing the detrimental effects of electrolyte contamination on pouch-type LiBs’ long-term cycle life and reliability.

Hybridized Triboelectric‐Electromagnetic Nanogenerator for Wind Energy Harvesting to Realize Real‐Time Power Supply of Sensor Nodes

AbstractAs the power consumption of various electronic devices is gradually reduced to milliwatt or even microwatt level, it is possible to achieve self‐powered electronic devices by obtaining weak energy from the environment. In this article, a hybrid nanogenerator that contains two working parts, —the triboelectric nanogenerator (TENG) in sliding independent layer mode and the electromagnetic generator (EMG) in rotating mode, is reported. The hybrid generator can effectively broaden the output voltage range while shortening the voltage boost time. After polishing the surface of nylon film with different mesh sandpaper, the maximum increase of output voltage and current can reach 60% and 80%, respectively. When the wind speed is 9 m s–1, the maximum average output power values of TENG and EMG are 0.33 and 32.87 mW, respectively. Also the hybrid nanogenerator can stably power 200 light‐emitting diodes (LEDs) and hygro‐thermograph after working for 2 s. Compared with the method of supplying power to electronic devices after a long period of energy storage, the triboelectric‐electromagnetic hybrid nanogenerator that is designed can realize real‐time power supply for wireless sensor nodes and Bluetooth modules at a wind speed of 10.5 m s–1, and the voltage at both ends is always maintained dynamic equilibrium.

Ag/VO2/Ag sandwich nylon film for smart thermal management and thermo-responsive electrical conductivity

Due to the effects of climate changing, the importance of outdoor thermal comfort has been recognized, and has gained more and more research attentions. Unlike indoor space where air conditioning can be easily implemented, outdoor thermal comfort can only be achieved by localized thermal management. Using textile is a simple but energy-saving way to realize outdoor thermal comfort. Herein, we report the design of a smart thermal management film with the silver/vanadium dioxide/silver (Ag/VO2/Ag) sandwich structure prepared by one-dimensional (1 D) nanowires. It was found that the Ag/VO2/Ag sandwich film was able to lower the temperature by around 10 °C under intense infrared (IR) radiation. In addition, the Ag/VO2/Ag sandwich structure film showed a thermo-responsive electrical conductivity and an outstanding bending stability, due to network structure formed by nanowires. It was experimentally proved that this sandwich structure was superior to other layer structures in IR shielding performance and thermo-responsive electrical conductivity. The as-prepared Ag/VO2/Ag sandwich structure film has great potential for various applications such as wearable devices, flexible electronics, medical monitors and smart IR radiation management.

A self-powered grip exerciser based on triboelectric nanogenerator for intelligent sports monitoring

ABSTRACT With the advent of the new era of the internet of things (IoT), data acquisition and analysis based on distributed sensors is becoming more and more important. Here, we designed a novel double-arch triboelectric nanogenerators (DA-TENG) based on the polytetrafluoroethylene (PTFE) film and the Nylon film. A self-powered grip exerciser test system based on the DA-TENG has been developed, and it can reflect the grip strength and exercise frequency. The WT-TENG can stay stable output performance several consecutive operations and has wonderful electrical output. The maximum Voc and Isc of DA-TENG can achieve 394.98 V and 37.48 µA, respectively. And the maximum output power can arrive at 1.0368 mW. This work will promote the development of intelligent sports.

Active Bio-Based Pressure-Sensitive Adhesive Based Natural Rubber for Food Antimicrobial Applications: Effect of Processing Parameters on Its Adhesion Properties.

A novel active bio-based pressure-sensitive adhesive incorporating cinnamon oil (Bio-PSA/CO) obtained from the mixture of natural rubber (NR), xyloglucan (XG), and cinnamon oil (CO) for food antimicrobial applications were successfully developed by using a two-roll mill mixer. The effect of the main process factors (i.e., nip gap and mastication time) and XG content on the adhesion properties of the obtained PSA were investigated with different coated substrates including kraft paper, nylon film, polypropylene (PP) film, and aluminum foil (Al). The results suggested that the developed NR-PSA/CO could be applied well to all types of substrate materials. Peel strength and shear strength of the NR-PSA/CO with all substrate types were in the ranges of ~0.03 × 102–5.64 × 102 N/m and ~0.24 × 104–9.50 × 104 N/m2, respectively. The proper processed condition of the NR-PSA/CO was represented with a nip gap of 2 mm and a mastication time of 15 min. An increase in XG content up to 40–60 phr can improve the adhesion properties of the adhesive. The resulting material could be used as an active sticky patch to extend the shelf-life of food in a closed packaging system. The shelf-life of the food samples (banana cupcake) could be extended from 4 to 9 days with NR-PSA/CO patch.

Versatile fabrication of liquid metal nano-ink based flexible electronic devices

Liquid metal (LM) of eutectic Gallium-Indium (EGaIn) possesses room temperature fluidity and excellent conductivity, allowing for promising potentials in flexible electronics. However, it is a considerable challenge to fabricate LM based circuits due to high surface tension of EGaIn. Here, we present a polyvinylpyrrolidone (PVP) stabilized LM nano-ink with excellent colloidal stability can be employed for constructing flexible devices by versatile fabrication strategies. By direct-writing, the circuits can be fabricated on common paper, followed by mechanical sintered to recover conductivity. The circuits can be then enveloped by temperature-controlled roll laminator for its practical durability. By filtration, LM nanodroplets were sucked into the porous structure of a Nylon film to form conductive membrane, which could restore conductive property by friction sintering. Subsequently, customized conductive pattern readily obtained by laser cutting could be encapsulated in flexible material of Ecoflex, yielding different flexible devices including NFC antenna, capacitor based pressure sensor and bio-electrodes for nerve signal sensing of living mice in vivo. The current work presents versatile fabrication strategies of LM nano-ink based flexible electronics, which hold great possibilities in the field of printed electronics. Furthermore, the LM nano-ink that reconciles stability and biocompatibility provides huge potential for future implanted flexible electronics.

Controlling Performance of Organic–Inorganic Hybrid Perovskite Triboelectric Nanogenerators via Chemical Composition Modulation and Electric Field‐Induced Ion Migration

AbstractIn this paper, new strategies are proposed to design high‐performance organic–inorganic hybrid perovskite (PVK)‐based triboelectric nanogenerators (TENGs) via both chemical composition modulation and electric field‐induced ion migration in the films. Both composition variation and ion migration under electric field are found to change the type of conductivity of the perovskite films, then modify their surface potentials and electron affinities. These are utilized to fabricate PVK‐based TENGs in pairs with poly‐tetrafluoroethylene (PTFE) or nylon films, respectively. Results show that PVK films are able to work as either a positive or a negative tribo‐material depending on the tribo‐material pair used; the optimal performances are obtained for PTFE/PVK TENGs using a PVK film with a MAI/PbI2 ratio of 2 and forward polarization, and for nylon/PVK TENGs using a PVK film with a MAI/PbI2 ratio of 0.4 and reverse polarization, respectively. The maximum output voltage and peak power density of PTFE/PVK TENGs are about 979 V and 24 W m−2, 2.5 and 6.5 times higher than those of TENGs with nonoptimal composition ratio or that are poorly polarized. This work provides a new material design method for high‐performance TENGs and a novel polarization strategy for TENG performance enhancement.

Observing a Chemical Reaction at a Buried Solid/Solid Interface in Situ.

Chemical reactions are the most important phenomena in chemistry. However, chemical reactions at buried solid/solid interfaces are very difficult to study in situ. In this research, the chemical reaction between two solid polymer materials, a nylon film and a maleic anhydride (MAH) grafted poly(ethylene-octene) (MAHgEO) sample, was directly analyzed at the buried nylon/MAHgEO interface at the molecular level in real time and in situ, using surface and interface sensitive sum-frequency generation (SFG) vibrational spectroscopy. Disappearance of nylon signals indicated a chemical reaction between amine and hydrolyzed amide groups of nylon and MAH groups on the MAHgEO at the buried interface. The appearance of SFG signals from reaction products was also observed at the buried nylon/MAHgEO interface. The mechanism of the observed interfacial reaction was further analyzed. Temperature-dependent SFG experiments were performed to measure the activation energy of the interfacial reaction, enabling a comparison with that reported for the bulk materials. The interfacial chemical reaction between nylon and MAHgEO greatly improved the adhesion of these dissimilar materials. The detailed analysis of a chemical reaction between two polymers at the polymer/polymer buried interface underscores the utility of SFG as a powerful analytical tool to build understanding of buried interfaces and to accelerate the design of interfacial structures with desired properties.

Experimental and Numerical Investigation of Cutting Characteristics of PA6/PE Nylon Film Subjected to Wedge Indentation Process

In this research work, we aim to evaluate the cutting resistance and deformation of a laminated nylon film subjected to a 42o wedged indentation. One of the problems occurred in the wedge indentation process is the unstable separation and quality of the sheared profile of the worksheet. In order to reveal the effect of cutting parameters on the cutting features, the indentation experiment of 0.16 mm thickness of Polyamide-6/ Polyethylene nylon film (PA6/PE) was conducted; the cutting line force was gotten using a recording unit; the bent-up angle and sheared profile of the worksheet were observed using a high-speed camera. From the experiment results, it was found that the cutting direction was an important factor affected to the bent-up angle and cutting load response of the nylon film. Also, the effect of cutting direction (PA6-PE and PE-PA6) of the nylon film was numerically investigated.

Double-piezoelectric-layer-enhanced triboelectric nanogenerator for bio-mechanical energy harvesting and hot airflow monitoring

Recently, the vigorous development of flexible piezoelectric nanogenerator and triboelectric nanogenerator (TENG) has attracted more and more attention from researchers. In this paper, we reported a novel double-piezoelectric-layer-enhanced TENG (DP-TENG) to harvest mechanical energy. The DP-TENG can also serve as a self-powered deformation sensor to detect bending motion. To realize the large-scale production and wide application, a sample fabrication method was developed to prepare DP-TENG using low-cost commercial materials, such as PTFE film, Nylon film, and PVDF film. Besides, the DP-TENG can be used to monitor the flow of hot air to serve as a self-powered temperature sensor. This research has provided an effective structural design about piezoelectric-enhanced TENG for harvesting environment mechanical energy, which has bright potentials in the field of self-power deformation system and airflow temperature monitoring.

Photo‐crosslinked gelatin–polyvinyl alcohol composite films: UV–riboflavin treatment for improving functional properties

In this study, physicochemical and structural properties of films based on gelatin (G), polyvinyl alcohol (PVA), and composite films (0PVA:1G, 1PVA:2G, 1PVA:1G, 2PVA:1G, 1PVA:0G) using photo-oxidation (in the presence of sensitizer riboflavin) were investigated. UV barrier of the UV-treated films was significantly improved as the light transmission at a wavelength of 200–350 nm was obtained from 0% to 0.7%. The photosensitizer-induced cross-linking significantly decreased water vapor permeability and solubility of the films. The results demonstrated that the mechanical properties of UV-treated films were significantly improved compared to the control sample. The tensile strength (TS) improved by increasing the gelatin content in composite films where the 1PVA:2G treatment showed the highest TS (61.13 MPa). SEM images also showed a dense and homogenous tissue in 1PVA:2G compared to the other composite films. According to DSC and FTIR results, the most efficient interactions were established for 1PVA:2G composite film. The obtained results showed the effectiveness of the photo-oxidation process in improving films’ properties encouraging the use of this method in the production of biodegradable films. Practical applications In this study, according to the experiments, the photo-oxidation process with riboflavin as a sensitizer can increase the physicochemical properties of the biodegradable films by increasing the interaction between the ingredients even better than typical nylon films such as heat resistance, tensile strength, mechanical properties, and lack of UV and moisture permeability. This production technique can be tested in the industry to produce packaging with better properties.

Optogenetic brain neuromodulation by stray magnetic field via flash-enhanced magneto-mechano-triboelectric nanogenerator

Abstract Optogenetic neuromodulation is a promising technology for continuously caring various neurological diseases. Optogenetic modulating systems were demonstrated by several researchers, but still have critical issues of short lifetime of conventional or biocompatible batteries. Here, we present an optogenetic stimulating system by scavenging wasted magnetic field of home appliance. A flash-enhanced magneto-mechano-triboelectric nanogenerator (MMTENG) was fabricated to demonstrate optogenetic neuromodulation by operating a flexible micro-light-emitting diode (f-μLED). The output performance of MMTENG was enhanced by the flash-induced nano/microscale surface structure of the triboelectric Nylon film. The flash-stamped MMTENG effectively generated an open-circuit peak-to-peak voltage (Vpp) of 870 V and a short-circuit current of 145 μA under a gentle alternating current (AC) magnetic field of 7 Oe. A maximum peak power of 8.1 mW was observed from the flash-induced harvester, which was 2.6 times higher than the non-treated device. A high-performance f-μLED with low-resistive ohmic contacts had the improvement of thermal/mechanical stability as well as power efficiency. The MMTENG generated a rectified output voltage of 134 V by a 60 Hz stray magnetic field of home appliance, enabling to operate the f-μLED continuously. An optogenetic stimulator composed of MMTENG and f-μLED was implanted under a living mouse skull without mechanical damage.

Acetaldehyde gas removal by a nylon film–TiO2 composite sheet prepared on a paper surface using interfacial polymerization and electrostatic interactions

In this study, preparation of a nylon film–TiO2 composite sheet with both physical durability under UV irradiation and TiO2 photocatalysis functionality was investigated. First, a nylon film was directly prepared on paper by interfacial polymerization using ethylenediamine and terephthaloyl chloride in a cyclohexane–chloroform mixture (3:1, v/v). Next, the nylon-coated paper was treated with tetraethyl orthosilicate and 3-aminopropyltrimethoxysilane to prepare polysiloxane on its surface. This was followed by fixation of TiO2 powder via electrostatic interactions with the polysiloxane. Although nylon films on paper usually decompose under TiO2 photocatalysis, the nylon film–TiO2 composite sheets prepared using 0.5%–1.0% (w/v) TiO2 did not decompose under photocatalysis. The residual rate of strength of the sheet remained at almost 100% after 240 h, which could be attributed to protection of the sheet by the polysiloxane layer. The nylon film was fibrous and could effectively adsorb acetaldehyde gas. All of the nylon film–TiO2 composite sheets prepared using 0.5%–5.0% TiO2 photocatalytically removed acetaldehyde under UV irradiation and no acetaldehyde gas was detected after 240–300 min. These results show the nylon film–TiO2 composite sheet can effectively remove acetaldehyde gas by photocatalysis and adsorption and could be applied to removal of volatile organic compounds in indoor air.

Colossal dielectric permittivity of Nylon-6 matrix-based composites with nano-TiO2 fillers

Herein, the nanocomposite films of Nylon-6 with reinforced nano-TiO2 were explored for their charge storage capacity. The high dielectric constant (e) of TiO2, along with its compatibility with Nylon-6, formed the basis for the present study. TiO2 nanoparticles were synthesized initially using hydrothermal technique. The microscopic uniformity and anatase-phase purity of the TiO2 nanoparticles were confirmed with the help of morphological and structural investigations. The effect of weight fraction of TiO2 in Nylon-6 was investigated to understand the robustness of the fabricated nanocomposites. The composite films with 5, 10 and 20 wt% of TiO2 in Nylon-6 matrix were prepared, and their dielectric behavior was explored by fabricating capacitors with parallel plate architecture. The composite film with 20 wt% TiO2 showed the highest dielectric parameters. The nanocomposite films have the exceptional dielectric quality with e ~ 124 and low dielectric loss of 0.51 at 1 kHz. The colossal dielectric nature along with minimum sophistication in the film fabrication process makes the present nanocomposite to be a potential candidate for the various electronic devices.

Exploring the Dynamics of Bound Water in Nylon Polymers with Terahertz Spectroscopy.

Terahertz (THz) spectroscopy was used to observe adsorbed water structure and dynamics within polymer films, ultimately providing a strong rationale for the observed rates of water desorption. The THz absorption spectra of nylon-6 films undergo drastic changes during the hydration and drying processes. Additionally, the structural change from γ to α crystals, induced by the hydration, was observed by the characteristic band of α-nylon-6 at 6.5 THz. Importantly, the THz spectra of adsorbed water, as well as deuterated water, within in the nylon films were observed by the continuous measurement of α-nylon during dehydration. The difference spectra clearly show three absorption bands of water molecules named Peaks I-III, which behave differently between the H2O and D2O materials. The spectra were assigned using a combination of ab initio molecular dynamics simulations and solid-state density functional theory calculations and were compared to previous spectral assignments of bulk water. The results show that the inclusion of H2O and D2O into polymer films results in a distinct set of spectral features that, while similar in frequencies to the dynamics of bulk water, represent significantly different motions owing to the unique chemical environment within the material. These results highlight the significant utility of using THz spectroscopy to study the hydration dynamics and spectral signatures of bound water in this important class of materials.

Experimental study on the formability of aluminum pouch for lithium polymer battery by manufacturing processes

Lithium polymer batteries are an improvement from the existing lithium ion batteries in terms of the risks of electrolyte leakage and explosion. Demand for lithium polymer batteries is rapidly increasing because of their advantages such as stability, light, and higher degree of freedom of shape. Accordingly, the demand for aluminum pouches, which are the exterior material of lithium polymer batteries, is increasing and research and development of aluminum pouches are actively being conducted. In the case of aluminum pouches, the forming area and depth that can accommodate the battery cell are increased according to the capacity of the battery, and stable formability is essential for aluminum pouches. In this study, manufacturing processes were changed to examine ways to improve formability. First, by changing the process order so that the surface treatment coatings on both sides of the aluminum foil were carried out simultaneously, the number of times when there was contact of the nylon film with the work roll was reduced. As a result, formability was improved because damage to the surface of the nylon film was reduced and the slipperiness was maintained. In addition, with regard to the drying temperature of the adhesive that constitutes the innermost layer, as the drying temperature increased (120 °C), solvent volatility increased, leading to stronger adhesion between the interfaces and resulting in improved formability.