Glass Fiber Substrate Research Articles

Life cycle assessment (LCA) of circular consumer electronics based on IC recycling and emerging PCB assembly materials

As consumer microelectronics become ever more ubiquitous, there are growing concerns about their environmental impact. However, the diversity of designs and components used in modern devices makes a coherent mitigation strategy hard to formulate. In this work, we perform a quantitative life cycle assessment (LCA) of the environmental profiles of both high-value (a smartwatch) and low-value (a TV remote) devices and find that the optimal mitigation strategy varies substantially between these two extremes. We find that the impact of the smartwatch is dominated by the production costs of its integrated circuits (ICs), and so a priority on device lifetime and design-for-recycling of the ICs is the best path to minimizing impact. On the other hand, the TV remote’s impact is dominated by the cost of its fiberglass (FR4) substrate, with the much simpler ICs playing a much smaller role. Our results show that the impact of low-cost devices is best mitigated by incorporating eco-friendly substrates and additive manufacturing techniques, while also minimizing the use of critical raw materials (CRMs). These results will help guide future industrial strategies, and we provide a list of challenges and opportunities in making electronics green.

A Facile Strategy for Constructing High‐Performance Polymer Electrolytes via Anion Modification and Click Chemistry for Rechargeable Magnesium Batteries

AbstractPolymer electrolytes play a crucial role in advancing rechargeable magnesium batteries (RMBs) owing to their exceptional characteristics, including high flexibility, superior interface compatibility, broad electrochemical stability window, and enhanced safety features. Despite these advantages, research in this domain remains nascent, plagued by single preparation approaches and challenges associated with the compatibility between polymer electrolytes and Mg metal anode. In this study, we present a novel synthesis strategy to fabricate a glycerol α,α′‐diallyl ether‐3,6‐dioxa‐1,8‐octanedithiol‐based composite gel polymer electrolyte supported by glass fiber substrate (GDT@GF CGPE) through anion modification and thiol‐ene click chemistry polymerization. The developed route exhibits novelty and high efficiency, leading to the production of GDT@GF CGPEs featuring exceptional mechanical properties, heightened ionic conductivity, elevated Mg2+ transference number, and commendable compatibility with Mg anode. The assembled modified Mo6S8||GDT@GF||Mg cells exhibit outstanding performance across a wide temperature range and address critical safety concerns, showcasing the potential for applications under extreme conditions. Our innovative preparation strategy offers a promising avenue for the advancement of polymer electrolytes in high‐performance rechargeable magnesium batteries, while also opens up possibilities for future large‐scale applications and the development of flexible electronic devices.

A Facile Strategy for Constructing High-Performance Polymer Electrolytes via Anion Modification and Click Chemistry for Rechargeable Magnesium Batteries.

Polymer electrolytes play a crucial role in advancing rechargeable magnesium batteries (RMBs) owing to their exceptional characteristics, including high flexibility, superior interface compatibility, broad electrochemical stability window, and enhanced safety features. Despite these advantages, research in this domain remains nascent, plagued by single preparation approaches and challenges associated with the compatibility between polymer electrolytes and Mg metal anode. In this study, we present a novel synthesis strategy to fabricate a glycerol α,α'-diallyl ether-3,6-dioxa-1,8-octanedithiol-based composite gel polymer electrolyte supported by glass fiber substrate (GDT@GF CGPE) through anion modification and thiol-ene click chemistry polymerization. The developed route exhibits novelty and high efficiency, leading to the production of GDT@GF CGPEs featuring exceptional mechanical properties, heightened ionic conductivity, elevated Mg2+ transference number, and commendable compatibility with Mg anode. The assembled modified Mo6S8||GDT@GF||Mg cells exhibit outstanding performance across a wide temperature range and address critical safety concerns, showcasing the potential for applications under extreme conditions. Our innovative preparation strategy offers a promising avenue for the advancement of polymer electrolytes in high-performance rechargeable magnesium batteries, while also opens up possibilities for future large-scale applications and the development of flexible electronic devices.

Triazine and hydroxyl covalent organic framework modified separator for Zn-ion fast and Selective transport and dendrite-free deposition in zinc–iodine battery

Aqueous zinc–iodine (Zn–I) batteries show a great development potential in the field of energy storage due to their advantages of low cost, high safety and ecological friendliness. However, Zn dendrite growth and shuttle effect of polyiodide seriously aggravate the self-discharge behavior and thus decrease the cycle life of batteries. Therefore, controlling the diffusion of zinc ion and inhibiting soluble polyiodide in the separator are the most effective strategy to extend the lifespan of batteries. Herein, we design and prepare a multifunctional Janus separator composed of a covalent organic framework (COF) layer, a commercial glass fiber (GF) substrate and a graphene (Gr) layer to achieve durable Zn–I batteries. The COF layer features abundant polar groups and uniform open-channel mesopores enabling homogeneous Zn2+ flux and simultaneously inhibiting polyiodide species migration. The highly conductive Gr layer can not only load iodide but also effectively activate the redox kinetics of iodine species. The full cell assembled with the TTA-DHTPA-COF@GF@Gr Janus separator demonstrated a recorded energy density of up to 6.4 mA h·cm−2 at a high current density of 20 mA cm−2 in aqueous Zn–I batteries. The design of the multifunctional Janus separator provides a new insight into separator engineering for durable Zn-ion batteries.

Fabrication and Implementation of PVA Thin Film-based Relative Humidity Sensor

This paper presents the fabrication of polyvinyl alcohol (PVA)-based relative humidity sensors using copper interdigitated electrodes (IDEs). These sensors were fabricated by patterning copper IDEs onto FR4 fiberglass substrates and coating them with a thin film of PVA. By varying the number of IDE electrode pairs and the concentration of PVA, the sensors exhibited different resistance values, demonstrating an inverse relationship with the number of IDE electrodes and PVA concentration. Additionally, the thickness of the sensing layer, controlled by spin coating speed, affected the resistance of the sensors. The fabricated sensors achieved a humidity measurement range from 50% to 99% RH based on resistance changes. Furthermore, an interface circuit was designed to integrate the fabricated sensors with an ESP8266 microcontroller, achieving accurate measurements above 74% RH.

A carbon nanotube-based thermoelectric generator integrated into a smart composite for structural health monitoring

The next generation of advanced composite materials needs to simultaneously address issues such as energy harvesting and structural health monitoring (SHM). The objective of this study is to explore, for the first time, the possibility of utilizing a build-in thermoelectric generator (TEG) to fulfil self-sensing purposes. To this end, carbon nanotube-based (CNT) inks are employed to print TEGs onto a glass fiber substrate, which is then incorporated into a glass fiber reinforced polymer (GFRP) laminate. The output characteristics of the TEG-enabled specimens are measured, displaying an exceptional performance. The specimens are subjected to static, quasi static cyclic and dynamic loading. Adopting a novel idea, the conductive, fully integrated printed path is then exploited to serve as a strain/damage sensor. For this reason, its resistance is monitored online during mechanical loading. To corroborate the findings, acoustic emission (AE) is simultaneously applied. Results reveal that the self-sensing multifunctional composite can successfully monitor its structural integrity. In fact, it demonstrates high sensitivity with a gauge factor approximately equal to 3. Moreover, when the TEG operates as a piezoresistive sensor, it is characterized by reliability. We thus believe that the herein suggested approach unveils new prospects regarding the efficiency and the sustainability of composite structures.

Design and characterization of a circularly polarized microstrip-line-fed slot array antenna for S-band applications

A 2×2 slot array antenna fed by microstrip line for circular polarization operated in the S band frequency range is designed in this paper. Single cross slot with single port feed as well as dual port feed is taken into consideration for realizing circular polarization and combining these two processes, the slot array is designed with single feed for circular polarization. The antennas are designed on a Teflon glass fiber substrate of thickness 0.8 mm. The slot array dimension is 120×142×1.636 mm<sup>3</sup>. Smith chart of single cross slot antenna with single feed as well as dual feed has a dip at 2.69 and 2.53 GHz respectively indicate the capability of realizing circular polarization in the S band frequency range. The return loss of the slot array antenna is -58 dB shows good input impedance matching of the antenna. A dip in the smith chart of the slot array shows circular polarization near 2.4 GHz ensuring wireless applications as well. Axial ratio is found to be less than 1 dB in the resonance frequency. The impedance bandwidth percentage of the slot array antenna is 12.24%. The simulation is done by using keysight advanced design system (ADS) software.

Promising Smart Materials for Radioelectronics

The investigations of a multilayer material – a polymeric radio-transparent electrically conductive film of polyaniline with a concentration of 5, 10 and 50 % by weight on a radio-transparent fiberglass substrate were carried out. Such materials are multifunctional – the material itself has the required characteristics, but when it is exposed to external electromagnetic radiation, it provides shielding functions. Electrically conductive polymer samples (polyaniline film) deposited on a fiberglass substrate have low attenuation in the 8–12 GHz transparency band, low electromagnetic radiation reflection coefficient, high conductivity and performance characteristics, as well as manufacturability.

Selective Colorimetric Detection of Novichok Agents with Hydrazone Chemosensors.

Novichok is a recently identified class of neurotoxic organophosphorus compounds that have subsequently been banned by the Organization for Prohibition of Chemical Weapons (OPCW) as chemical warfare agents. Selective, rapid detection of Novichok remains a challenge. Several colorimetric paper-based detection devices have recently been developed for the rapid and selective detection of sarin, VX, and sulfur mustard. In this article, we present a similar colorimetric device designed specifically for the detection of Novichok, based on hydrazone derivatives from 2,4-dinitrophenylhydrazine (2,4-DNPH) impregnated on a glass fiber substrate. Results show that these compounds rapidly and selectively reveal the presence of Novichok agents to the naked eye. The low cost, ease of use, portability, and high selectivity to Novichok of this device complete the detection range of colorimetric paper-based sensors for chemical warfare agents.

A Janus separator towards dendrite-free and stable zinc anodes for long-duration aqueous zinc ion batteries

Critical issues of Zn anodes including undesirable dendrites formation and parasitic reactions severely limit the reversibility and cyclability of Zn anodes. To address these issues, a functional Janus separator with the structure of a mechanically strong sulfonated poly(arylene ether sulfone) (SPAES) dense layer composited on a porous glass fiber (GF) substrate is designed. The SPAES dense layer that faces the Zn anode containing abundant sulfonic acid groups effectively promotes the desolvation process of hydrated Zn ions, guides uniform Zn ion transfer, and blocks anions and water, contributing to dendrite-free and highly reversible Zn plating/stripping cycles, while the porous GF substrate retains high electrolyte uptake. As a result, the Zn symmetric cell with the Janus separator demonstrates an ultralong cycling lifespan of over 2000 h at the areal capacity of 1 mA h cm−2, which is 23-fold superior to that with a pristine glass fiber separator (<90 h). More impressively, the as-prepared Janus separator enables outstanding rate performance and excellent cycling stability of full Zn ion batteries with diverse cathode materials. For instance, when paired with the V2O5 cathode, the full battery with a Janus separator attains an ultrahigh initial specific capacity of 416.3 mA h g−1 and capacity retention of 60% over 450 cycles at 1 A g−1, exceeding that with a glass fiber separator. Hence, this work provides a facile yet effective approach to mitigating the dendrites formation and ameliorating the parasitic reactions of Zn metal anodes for high-performance Zn ion batteries.

A nanocellulose-mediated, multiscale ion-sieving separator with selective Zn2+ channels for durable aqueous zinc-based batteries

A heterostructure engineered, multiscale ion-sieving separator with desired macro‑meso-molecular pores that can render selective Zn2+ permeability and homogeneous Zn2+ distribution at the separator-electrode interface is designed to achieve durable aqueous Zn-ion batteries. The proposed separator is fabricated by stacking an intermediate nanocellulose layer and a poly(3,4-ethylenedioxythiophene):polystyrene sulfonate (PEDOT:PSS) upper layer on a glass fiber substrate, wherein the nanocellulose layer contains uniform mesopores favoring a homogeneous Zn2+ flux and endowing the attainment of a PEDOT:PSS layer. While the PEDOT:PSS layer features intrinsic ionic/electronic conductivity and rich sulfonate groups enabling uniform electrical field distribution and inhibiting anions migration. The combination of mesoporous nanocellulose and cation-permeable PEDOT:PSS used in the heterostructure separator yields a high ionic transference number and fast Zn2+ desolvation kinetics. This unique separator enables highly compact and dendrite-free Zn deposition at 4 mA cm−2/8 mAh cm−2, and sustains the symmetric Zn||Zn cell over 400 h at 10 mA cm−2/4 mAh cm−2. Such advantages bring remarkable reversibility to full AZBs with high I2 mass loading cathodes of 13.0 mg cm−2, delivering a discharge capacity of 172.1 mAh g−1 after 1000 cycles. This multiscale ion-sieving design principle provides new insight into separator engineering for ultra-stable Zn metal batteries.

Antenna design and implementation patch diamond array 2x4 elements with DGS shaped dumbbell square head at frequency 2.4 GHz

— Technological advances in the field of telecommunications without cables or wireless are growing rapidly by utilizing radio waves as transmission. This happens because people's mobility is currently quite high and requires practicality in the use of devices. The discussion in this paper is about the comparison of the design and fabrication performance of a diamond microstrip patch antenna composed of a 2x4 element array using DGS and without using DGS. The design was carried out using the CST 2018 simulator. The DGS was placed on a PCB ground plane with an epoxy fiberglass substrate having a dielectric constant of 4.58. This is measured by improving the value of VSWR, return loss, and bandwidth. The application of the working frequency used by the microstrip antenna is at (2401-2495) MHz for WIFI (Wireless Fidelity) networks. Microstrip antennas have a narrow bandwidth shortage, so they require bandwidth widening using the DGS (Defected Ground Structure) technique in the form of dumbbell square ahead. The resulting bandwidth is 15 MHz wider than a microstrip antenna without DGS. This research is in accordance with the antenna test parameters, which have a return loss value of -24.3dB, VSWR 1.12 and a bandwidth of 34 MHz.

An improved 2×2 array antenna using both-sided microwave integrated circuit technology for circular polarization

&lt;span lang="EN-US"&gt;A circularly polarized microstrip patch array antenna using both-sided microwave integrated circuit (MIC) technology with a triple feed network has been proposed in this article. The antenna elements, feed structure and both-sided &lt;a name="_Hlk112828933"&gt;&lt;/a&gt;MIC technology are used and arranged in such a way to obtain circular polarization alongside high gain without using an external matching circuit. The 50 Ω microstrip line is used to energize the antenna where the antenna’s total feed network is made up of both series and parallel combinations of microstrip and slot line. The antenna was realized using Teflon glass fiber substrate &lt;/span&gt;&lt;em&gt;&lt;span lang="EN-US"&gt;(ε&lt;sub&gt;r&lt;/sub&gt;)&lt;/span&gt;&lt;/em&gt;&lt;span lang="EN-US"&gt;=2.15 with a thickness of 0.8 mm. The antenna has some splendid parameters including S&lt;sub&gt;11&lt;/sub&gt; of less than -35 dB, a gain of 12 dBi with an omnidirectional pattern and an axial ratio of 0.7 dB at the operating frequency. The antenna possesses a bandwidth of 430 MHz (4.22%) after operating at X-band in the frequency spectrum. The antenna’s simulated parameters were investigated with the help of advanced design system (ADS) simulation software in microwave momentum mode.&lt;/span&gt;

Design and Implementation of 2x4 Element Hexagonal Array Microstrip Antenna with DGS Method in the Shape of Dumbbell Circle Head for 2.4 GHz Frequency Wi-Fi Applications

This study discusses the design and manufacture of microstrip antennas that aim to widen the bandwidth in the application of Wi-Fi in the form of a hexagonal patch composed of a 2x4 element array. Microstrip antennas have a weakness, namely narrow bandwidth, therefore a modification is needed using the DGS (Defected Ground Structure) method in the form of a dumbbell circle head. The allocation of the Wi-Fi working frequency that is often used in the community is 2.4 GHz in accordance with the IEEE 802.11 protocol standard. This study discusses the result and the effect of the performance of an 2x4-element microstrip array antenna using DGS. This DGS is placed on the ground plane and uses a PCB with an epoxy fiberglass substrate material which has a dielectric constant of 4.58. The result of this research is an external device, namely a microstrip antenna that can increase data transfer capacity and work on a Wi-Fi frequency of 2.4 GHz. This research is in accordance with the antenna test parameters, which have a return loss value of -22.7 dB and VSWR 1.15. 1. The results of testing the bandwidth of the hexagonal 2x4 element microstrip patch antenna with a defected ground structure of 34 MHz. The radiation pattern of the hexagonal 2x4 element microstrip patch antenna using DGS is directional. The results of the power level implementation of a hexagonal microstrip patch antenna arranged in a 2x4 array using a DGS dBm can increase power level by 7 dBm.

Acetylated tunicate nanocellulose-based high-efficient air filter media with antibacterial property

Nanocellulose has great potential for application in highly efficient filter media. However, its application is hindered significantly by the structure collapse of nanofiber networks due to capillary adhesion and hydrogen bonds formed during the wet-laid process. Here, the tunicate nanocelluloses (TNCs) are modified with acetic anhydride and (3-Aminopropyl) triethoxysilane, respectively, to alleviate such collapse of the nanofiber networks. The obtained acetylated tunicate nanocelluloses (ANCs) and silylated tunicate nanocelluloses (SNCs) are applied to fabricate composite filter media together with a glass fiber (GF) substrate layer. The filtration efficiency of TNC/GF, ANC/GF, and SNC/GF filter media increase to 99.983%, 99.991%, and 99.994%, respectively, compared with pure glass fibers filter media (99.916%). The smaller air resistance of ANC/GF filter media (314.3 Pa) compared to that of TNC/GF (323.9 Pa) and SNC/GF (346.7 Pa) filter media contributes to a larger quality factor (0.03 Pa-1). The ANC/GF filter media shows antibacterial capability. The survival rate of escherichia coli (E. coli) and staphylococcus aureus (S. aureus) bacteria with an original concentration of 2✕107 cell/mL decreased to 44.2% and 5.8%, respectively, after exposure to ANC/GF filter media for 6 h. Their survival rate decreased to less than 0.5% after exposure to the ANC/GF filter media loaded with silver nanoparticles for 1 h. This work will promote the application of nanocellulose in highly efficient air filter media.

Optimal Process Parameters for a Thermal-Sprayed Molybdenum-Reinforced Zirconium Diboride Composite on a Dummy Substrate

Thermal spray is an effective process for the fabrication of a metal matrix composite (MMC), where a zirconium diboride reinforcement is embedded in a molybdenum matrix to enable the combining of favorable properties in a new composite. The combination of two leading materials in the category of ultra-high-temperature ceramics (UHTCs) is due to a very high melting point (Mo: 2623 °C and ZrB2: 3245 °C), high thermal conductivity (Mo: 139 W/m°C and ZrB2: 24 W/m°C), good thermal shock resistance, low coefficient of thermal expansion (Mo: 5.35 µm/m°C and ZrB2: 5.9 × 10−6 K−1), retention of strength at elevated temperatures and stability in extreme environments. Thermal spraying of the Mo/ZrB2 composite possesses a non-linear behavior that is influenced by many coating variables. This characteristic makes finding the optimal factor combination difficult. Therefore, an effective and strategic statistical approach incorporating systematic experimental data is needed to optimize the process. In this study, the L9 orthogonal array in the Taguchi approach was utilized to optimize the spraying distance (SD), number of passes (NP), pressure (P) and coat-face temperature (TCF) using a dummy fiberglass substrate. The performance was evaluated based on the coating density (Cd) of the surfaces. Based on confirmation tests, our Taguchi analysis determined the ideal process parameters, which considerably enhanced the coating process. From the output response of the ANOVA, the most influential parameters for achieving a high coating density (Cd) were determined to be SD = 20 cm, NP = 24, P = 4 bar and TCF = 330 °C ((SD.)1-(NP.)3-P2-(S.T.)3). These observations show that the coating density (Cd) was significantly influenced by the coat-face temperature, followed by the number of passes, spraying distance and pressure with the following contributions 6.29, 17.89, 17.42 and 3.35%, respectively.

Thickness and internal adjustment of monolithic resin composite milled crowns: Effect on the load-bearing capacity under fatigue

ObjectivesTo evaluate the fatigue failure load (FFL), cycles for fatigue failure (CFF) and survival rates of different occlusal thicknesses of resin composite simplified crowns with internal adjustments (IA) or without as control (C). Methods30 monolithic simplified crowns of CAD/CAM resin composite (Tetric CAD, Ivoclar) were milled in three different occlusal thicknesses (0.5 mm, 1.0 mm, and 1.5 mm). Half of the crowns were submitted to restricted adjustment with diamond burs on the crown's inner surface and half remained milled without internal adjustment. The samples were treated and adhesively luted onto a prosthetic preparation made of epoxy resin reinforced by glass-fiber substrate. The sets were subjected to a fatigue test (cyclic fatigue: initial load of 200 N; step-size of 50 N; 10,000 cycles/step; 20 Hz; maximum load: 2800 N).Microscopic analysis of tested representative samples was performed. The fatigue data were statistically analyzed (α= 0.05) and the micrograpic images were qualitatively evaluated. ResultsAll specimens from groups 1.0C and 1.5C survived the cyclic loads, while all 0.5C samples failed during the test. The 1.0IA and 1.5IA crowns showed no statistical difference for FFL (2530 N= 2670 N) and CFF (471,000 cycles= 499,000 cycles) between them, and they were both statistically superior to the 0.5IA (FFL= 1812.50 N; CFF= 327,500 cycles). The 1.0 mm and 1.5 mm crowns presented superior fatigue behavior (2530 N–2800 N) compared to the 0.5 mm crowns (1812 N–2140 N), whether internal adjustment was performed or not. A statistically significant difference was found for FFL and CFF of 0.5 mm crowns with and without internal adjustment, with a deleterious impact of the adjustment for both parameters (FFL and CFF: 0.5C > 0.5IA). SignificanceResin composite milled crowns can bear high cyclic fatigue loads despite thickness, although thicker crowns had better mechanical behavior; however, the internal adjustment in the composite resin crown leads to a detrimental effect on its fatigue behavior, which presents a risk of mechanical failure due to premature fatigue.

Coating of silver nanoparticles (AgNPs) on glass fibers by a chemical method as plasmonic surface-enhanced Raman spectroscopy (SERS) sensors to detect molecular vibrations of Doxorubicin (DOX) drug in blood plasma

In the present study, Doxorubicin (DOX) drug in healthy blood plasma was the focus of the investigation by surface-enhanced Raman scattering (SERS). In recent years, chemotherapy has been the most popular treatment for various types of cancer; however, its adverse side effects on the patient's health have made a negative aspect regarding the use of this technique. DOX is the most common chemotherapy drug and is used for the treatment of an extensive range of human malignancies. The surface-enhanced Raman scattering (SERS) is a precise technique for the detection of chemicals and biomaterials with significantly low concentrations. The glass fiber substrates coated with silver nanoparticles (AgNPs) have been used to detect DOX. First, the Tollens' method was applied to prepare the AgNPs, and the characteristics of fabricated AgNPs were evaluated using ultraviolet–visible spectroscopy (UV–Vis) and X-ray diffraction (XRD). Then, AgNPs were coated on the glass fiber substrate by a chemical method. Finally, the enhancement of the Raman signal resulted from the molecular vibrations of DOX was evaluated using these SERS-active substrates as plasmonic and Raman spectroscopy sensors. Afterward, for making the sensors practical, the DOX in blood plasma were deposited on the fabricated sensors, and the Raman vibrations were evaluated. The SERS-active substrates, AgNPs deposited on glass fiber substrates, were fabricated for the detection of DOX in and out of the blood plasma; the limit of detection (LOD) for both was 10 −10 M, and the mean relative standard deviation at concentrations of 10 −10 M of DOX out of blood plasma, and 10 −10 M of DOX in blood plasma were obtained to be 3.76% and 3.61%, respectively for ten repeated measurements in which the AgNPs were SERS-active substrates of the biosensors for detecting the DOX. In addition, the enhancement factor was calculated both experimentally and via finite-difference time-domain (FDTD) simulation, which was 29.76 × 10 3 and 24.95 × 10 3 , respectively. Therefore, these SERS-active substrates can be used to develop microsensors and show positive results for SERS-based investigations.

Detection of molecular vibrations of atrazine by accumulation of silver nanoparticles on flexible glass fiber as a surface-enhanced Raman plasmonic nanosensor

Surface-Enhanced Raman Spectroscopy (SERS) is a sensitive vibration spectroscopy method applied to analyze a variety of analytes, including toxins and pesticides. The SERS method is an accurate method for detecting significantly low concentrations of biomaterials and chemicals. In the present study, in order to detect atrazine pesticide, the glass fiber substrates coated with silver nanoparticles have been used as SERS plasmonic nanosensors. First, silver nanoparticles were prepared by applying a chemical approach named the Tollens' method, and the SERS plasmonic substrates (SPS) were fabricated by depositing the colloidal silver solution on a glass fiber substrate. The SERS plasmonic nanosensors were fabricated by self-assembling the silver nanoparticles and after functionalization of glass fiber substrate using 3-aminopropyl triethoxysilane (APTES). For this purpose, silver nanoparticles were chemically prepared, and their size distribution was determined to be 140–150 nm using dynamic light scattering (DLS). Ultraviolet–visible spectroscopy was applied for the optical characterization of colloids of silver nanoparticles and the prepared substrates. The results indicate the displacement of the plasmonic peak toward longer wavelengths after self-assembly of the nanoparticles. Field emission scanning electron microscopy images indicated the non-uniform distribution of silver nanoparticles on the surface of glass fiber substrates. Atrazine pesticide was employed as an analyte to investigate the performance of SERS plasmonic substrates (SPS). The detection limit of SPS for detecting atrazine pesticide was equal to 10−12 M, and the average relative standard deviation for ten repeated measurements was obtained to be 4.02%. With reducing the solution concentration to 10−12 M, the intensity of Raman modes decreased significantly so that only some peaks were clear. Moreover, the quantum mechanics calculation and molecular dynamics simulation were performed to clarify the molecular interactions between atrazine and silver nanoparticles. By increasing the concentration of atrazine, the Lennard-Jones potential was increased following the experimental results of Raman spectroscopy.

Effects of flaming on polypropylene long glass fiber composites for automotive bonding applications with polyurethane

Flaming treatments have been used for many years in the automotive industry to improve the chemical affinity of polymers such as polypropylene with coatings. This study focuses on the adhesion of a specific bonded assembly: a methane-flamed polypropylene long glass fiber (PPGFL) substrate with a two-component polyurethane (PU) adhesive. The effects of the flaming treatment, specifically the equivalence ratio R and the exposure time t , are evaluated. The chemical and surface morphological modifications of the PPGFL caused by the flaming treatment are linked to the mechanical properties of the bonded assembly. Goniometer and X-ray photoelectron spectroscopy analyses reveal that the atomic percentage of grafted oxygen were at a maximum for a slightly flaming reducing mode: R = 1.06 and t = 25 ms. In addition, atomic force microscopy observations show nodular structures formed under these conditions, confirming greater oxidation. These results are consistent with the mechanical characterizations and are compared to those obtained after aging. Based on previous results, a chemical model of polypropylene flaming treatment is proposed. This model, as well as the known reaction mechanisms of the adhesive, allows us to highlight a particular group that plays an essential role in the adhesion of the PPGFL/PU system.