3M Tape Research Articles

Influence of laser treatment on the adhesion force of metallized carbon fiber reinforced polymer (CFRP) composite

Carbon fiber reinforced polymer (CFRP) is an engineering composite material with excellent performance. After metallization, the CFRP composite exhibits unique properties such as electromagnetic shielding and high electrical conductivity. In this study, we utilized laser treatment process to enhance the adhesion strength of the copper layer electrolessed on CFRP composite. The surface microstructure of CFRP and the copper layer was determined using an optical microscope, and the adhesion force of the copper layer on CFRP composite was measured through 3M tape and pull-out tests. The results indicate that with an increase in the number of laser treatment cycles, the trenches depth on the surface of CFRP composite also increases, leading to high surface roughness and thus enhancing the adhesion strength between the copper layer and the composite. The adhesion state of the copper layer on laser-treated CFRP composite can be qualitatively classified as grade 5B. Additionally, both mechanical cutting and laser treatment can improve the adhesion strength of the samples. The samples treated by mechanical cutting and the laser scan with ±45° exhibit the highest adhesion strength of 5.48 MPa. This is 415 % higher than that of the untreated sample, with a minimum damage area after pull-out testing, approximately 10 %. Compared to the sandblasting pretreatment process, the adhesion strength of the sample by laser treatment increased by 119 %.

Electroless silver plating on through-glass via (TGV) as an adhesive and conducting layer

The proposed method presents a scheme to modify the surface of the glass substrate using the piranha solution and to fabricate the conducting layer of the Through-glass Via (TGV) by the glucose-Ag electroless plating to achieve TGV metallization. The arithmetic mean deviation of the surface contours (Ra) for the substrates increases from 0.001 to 0.135. The contact angle of the substrates (unmodified and modified) is reduced to 6.4° and 12.2°, respectively. The sensitization process with SnCl2 and the activation process with silver ammonia solution are conducted using the glucose as the reducing agent to prepare the silver seed layer covered in the TGV through-vias with a high aspect ratio (9:1). The adhesion between the metal coating and the surface is measured by the 3M tape and chemical mechanical polishing (CMP). The metal coating adheres well to the surface-modified substrate without peeling off, which can satisfy the demands for the electroplating and CMP processes.

Optimization of an Ultrasound-Assisted Extraction Technique and the Effectiveness of the Sunscreen Components Isolated from Bletilla striata.

Bletilla striata is the dried tuber of B. striata (Thund.) Reichb.f., which has antibacterial, anti-inflammatory, anti-tumor, antioxidant and wound healing effects. Traditionally, it has been used for hemostasis therapy, as well as to treat sores, swelling and chapped skin. In this study, we used the ultraviolet (UV) absorbance rate of B. striata extracts as the index, and the extraction was varied with respect to the solid-liquid ratio, ethanol concentration, ultrasonic time and temperature in order to optimize the extraction process for its sunscreen components. The main compounds in the sunscreen ingredients of Baiji (B. striata) were analyzed using ultra-high-performance liquid chromatography combined with quadrupole time-of-flight tandem mass spectrometry. The sunscreen properties were subsequently evaluated in vitro using the 3M tape method. The results show that the optimal extraction conditions for the sunscreen components of B. striata were a solid-liquid ratio of 1:40 (g/mL), an ethanol concentration of 50%, an ultrasonic time of 50 min and a temperature of 60 °C. A power of 100 W and an ultrasonic frequency of 40 Hz were used throughout the experiments. Under these optimized conditions, the UV absorption rate of the isolated sunscreen components in the UVB region reached 84.38%, and the RSD was 0.11%. Eighteen compounds were identified, including eleven 2-isobutyl malic acid glucose oxybenzyl esters, four phenanthrenes, two bibenzyl and one α-isobutylmalic acid. An evaluation of the sunscreen properties showed that the average UVB absorption values for the sunscreen samples from different batches of B. striata ranged from 0.727 to 1.201. The sunscreen ingredients of the extracts from B. striata had a good UV absorption capacity in the UVB area, and they were effective in their sunscreen effects under medium-intensity sunlight. Therefore, this study will be an experimental reference for the extraction of sunscreen ingredients from the B. striata plant, and it provides evidence for the future development of B. striata as a candidate cosmetic raw material with UVB protection properties.

Fabrication of a Porous Low Refractive Index Anti-Reflective Coating with High Transmittance by Using the Porogen of Laureth-5 Carboxylic Acid

A porous anti-reflective coating (P-ARC) with average transmittance in the visible range of 97.9% was fabricated through the sol-gel method, followed by calcination at a relatively low temperature (220 °C) using the porogen of Laureth-5 carboxylic acid via a one-step approach. The results demonstrated the coating had an absolute value that was 7.5% higher than that of bare glass (92%). The prepared porous anti-reflective coating had a refractive index as low as 1.21. The coating remained undamaged during 3M tape stripping tests while maintaining excellent light transmittance. This work presents a film that has good thermal stability, chemical stability, and mechanical stability.

Innovative Solid Slippery Coating: Uniting Mechanical Durability, Optical Transparency, Anti-Icing, and Anti-Graffiti Traits.

Slippery coatings, such as the slippery liquid-infused porous surface (SLIPS), have gained significant attention for their potential applications in anti-icing and anti-fouling. However, they lack durability when subjected to mechanical impact. In this study, we have developed a robust slippery coating by blending polyurethane acrylate (PUA) with methyltriethoxysilane (MTES) and perfluoropolyether (PFPE) in the solvent of butyl acetate. The resulting mixture is homogeneous and allows for uniform coating on various substrates using a drop coating process followed by drying at 160 °C for 3 h. The cured coating exhibits excellent water repellency (contact angle of ~108° and sliding angle of ~8°), high transparency (average visible transmittance of ~90%), exceptional adherence to the substrate (5B rating according to ASTMD 3359), and remarkable hardness (4H on the pencil hardness scale). Moreover, the coating is quite flexible and can be folded without affecting its wettability. The robustness of the coating is evident in its ability to maintain a sliding angle below 25° even when subjected to abrasion, water jetting, high temperature, and UV irradiation. Due to its excellent nonwetting properties, the coating can be employed in anti-icing, anti-graffiti, and anti-sticking applications. It effectively reduces ice adhesion on aluminum substrates from approximately 217 kPa to 12 kPa. Even after 20 cycles of icing and de-icing, there is only a slight increase in ice adhesion, stabilizing at 40 kPa. The coating can resist graffiti for up to 400 cycles of writing with an oily marker pen and erasing with a tissue. Additionally, the coating allows for easy removal of 3M tape thereon without leaving any residue.

A Stretchable, Transparent, and Mechanically Robust Silver Nanowire-Polydimethylsiloxane Electrode for Electrochromic Devices.

The application of flexible indium tin oxide (ITO-free) electrochromic devices has steadily attracted widespread attention in wearable devices. Recently, silver nanowire/poly(dimethylsiloxane) (AgNW/PDMS)-based stretchable conductive films have raised great interest as ITO-free substrate for flexible electrochromic devices. However, it is still difficult to achieve high transparency with low resistance due to the weak binding force between AgNW and PDMS with low surface energy because of the possibility of detaching and sliding occurring at the interface. Herein, we propose a method to pattern the pre-cured PDMS (PT-PDMS) by stainless steel film as a template through constructed micron grooves and embedded structure, to prepare a stretchable AgNW/PT-PDMS electrode with high transparency and high conductivity. The stretchable AgNW/PT-PDMS electrode can be stretched (5000 cycles), twisted, and surface friction (3M tape for 500 cycles) without significant loss of conductivity (ΔR/R ≈ 16% and 27%). In addition, with the increase of stretch (stretching to 10-80%), the AgNW/PT-PDMS electrode transmittance increased, and the conductivity increased at first and then decreased. It is possible that the AgNWs in the micron grooves are spread during PDMS stretching, resulting in a larger spreading area and higher transmittance of the AgNWs film; at the same time, the nanowires between the grooves come into contact, thus increasing conductivity. An electrochromic electrode constructed with the stretchable AgNW/PT-PDMS exhibited excellent electrochromic behavior (transmittance contrast from ~61% to ~57%) even after 10,000 bending cycles or 500 stretching cycles, indicating high stability and mechanical robustness. Notably, this method of preparing transparent stretch electrodes based on patterned PDMS provides a promising solution for developing electronic devices with unique structures and high performance.

Influence of Pretreatment Processes on Adhesion of Ni/Cu/Ni Multilayer on Polyetherimide Resin Reinforced with Glass Fibers

The metallization of polyetherimide (PEI) is widely considered to enhance its surface properties and enhance its application in engineering fields; however, adhesion is a key factor in determining the reliability of PEI metallization. A Ni/Cu/Ni multilayer coating was successfully manufactured on a batch of PEI resin reinforced with glass fibers by a two-step metallization process, including sandblasting and activation/acceleration. The microstructure and morphology of the top-surface and cross-section of the coatings were observed by scanning electron microscopy. The chemical state and composition of the deposits were characterized by both X-ray photoelectron and energy-dispersive spectroscopy. The adhesion state was qualitatively evaluated by cross-cut tests with 3M tape. The surface roughness of the substrate significantly increased after the sandblasting process, which could improve the adhesion between the multilayer coating and the PEI substrate. After the standard activation process, the acceleration made an effect on the deposition of the initial Ni layer for electroless plating. The influence of acceleration on the appearance quality of metallization on the PEI substrate was studied and, at the same time, the mechanism of acceleration was investigated and addressed.

Novel Transparent TiO2/AgNW-Si(NH2)/PET Hybrid Films for Flexible Smart Windows.

The application of flexible indium tin oxide (ITO)-free electrochromic devices (FCDs) has always been a research hotspot in flexible electronics. Recently, a silver nanowire (AgNW)-based transparent conductive film has raised great interest as an ITO-free substrate for FCDs. However, several challenges, such as the weak binding of AgNWs to the substrate, high junction resistance, and oxidation of AgNWs, remain. In this paper, a novel method for surface modification of AgNWs with N-aminoethyl-γ-aminopropyltrimethoxysilane [Si(NH2)] solution is proposed to enhance the bonding with the flexible substrates and the active materials, thereby inhibiting the delamination of AgNWs from the substrate and reducing the high junction resistance between nanowires. The TiO2/AgNW-Si(NH2)/poly(ethylene terephthalate) (PET) films show outstanding mechanical properties, of which the resistance remains almost unchanged after mechanical bending of 5000 cycles (ΔR/R0 ≈ 3.6%) and repeated peeling off cycles with 3M tape 100 times (ΔR/R0 ≈ 6.0%). In addition, we found that the oxygen-containing groups on the TiO2/AgNW-Si(NH2)/PET surface form hydrogen bonds with the TiO2 sol, resulting in tight contact between the TiO2 sol and the AgNWs, which prevents the AgNWs from oxidation. As a result, the TiO2/AgNW-Si(NH2)/PET film exhibited long-time aging (ΔR/R0 ≈ 4.9% in the air for 100 days) stability. A FCD was constructed with the TiO2/AgNW-Si(NH2)/PET film, which showed excellent electrochromic performance (94% retention) after 5000 bending cycles, indicating high stability and mechanical flexibility. These results present a promising solution to the transparent conductive films for flexible energy devices.

High Interfacial Thermal Stability of Flexible Flake-Structured Aluminum Thin-Film Electrodes for Bi2Te3-Based Thermoelectric Devices.

Environmental thermal energy harvesting based on thermoelectric devices is greatly significant to the advancement of next-generation self-powered wearable electronic devices. However, the rigid electrodes and interface diffusion of electrodes/thermoelectric materials would lead to the wearable discomfort and performance degradation of the thermoelectric device. Here, a flake-structured Al thin-film electrode with high conductivity and excellent reliability is prepared by regulating the microstructure and crystallinity of the films. The as-prepared Al thin film not only maintains its robustness after 1000 bending cycles but also does not delaminate from the substrate when subjected to the 3M tape test, exhibiting excellent flexibility and adhesion to substrate. By comparing with the annealed interface of the double-layer Cu/Bi2Te3 film, the interface of the heat-treated Al/Bi2Te3 film has almost no element diffusion, demonstrating high interfacial thermal stability. Moreover, a thermoelectric temperature sensor based on the Al thin-film electrode is prepared. The sensitivity of the annealed sensor is still linear, and it can stably monitor the temperature variation, showing high reliability. This discovery could provide a facile and effective strategy to achieving highly reliable thermoelectric devices and flexible electronic devices without any additional diffusion barriers.

Evidence-based practice of self-made tracheal catheter fixation band in prevention of unplanned extubation

With the development of medical technology, the fixation method of the oral duct is constantly updated, and the selection of a relatively safe, effective, simple and fast fixation method of the oral duct has been widely concerned. However, the use of traditional 3M I-shaped tape fixation needs to be cut, which wastes time and easily leads to the outward displacement of the tracheal tube, and is easy to be soaked by oral secretions, resulting in facial skin damage. Therefore, the medical staffs of the department of critical care medicine of Hengshui People's Hospital designed a self-made tracheal catheter fixing band (composed of the main structure, the fixed band, the internal adjusting structure and the internal structure of the fixed block), and obtained the national utility model patent (ZL 2018 2 0508681.6). The inner side of the fixing band is fixed with a spongy body, which can absorb the secretions around the mouth to avoid the moist condition around the mouth and cheek skin. Meanwhile, the endotracheal catheter is fixed with the help of the card slot, hinge and other structures, which can fully ensure the fixation effect. A total of 80 patients undergoing airway intubation were admitted to the department of critical care medicine of our hospital from October 2020 to September 2021. They were divided into observation group and control group according to intubation time (single number and double number), with 40 patients in each group. The observation group was fixed with self-made tracheal catheter fixation band. Through evidence-based practice path, relevant literatures at home and abroad were searched for clinical practice basis, and the practice plan was formulated and implemented. The control group was fixed with 3M tape + inch tape according to the traditional method. The fixation of tracheal tube and the degree of facial skin injury were compared between the two groups. All patients were included in the final analysis without shedding cases. Severe catheter displacement occurred in 3 patients (7.5%) in the control group, and no severe catheter displacement occurred in the observation group. The incidence of facial skin injury in the observation group was significantly lower than that in the control group [25.0% (10/40) vs. 55.0% (22/40), P < 0.05]. Moreover, the fixation time of the observation group was significantly shorter than that of the control group (minute: 12.11±1.69 vs 17.59±1.27, P < 0.05). The application of self-made tracheal catheter fixation band can shorten the fixation time of tracheal catheter and reduce the incidence of unplanned endotracheal extubation (UEE) and facial skin injury, which is worthy of clinical promotion and application.

Direct printing of surface-embedded stretchable graphene patterns with strong adhesion on viscous substrates

The graphene patterns with piezoresistance behaviors, originating from the structural deformation and band-structure shift under strain, represent an attractive characteristic for developing the small strain (<10%) sensors for wearable devices. However, the insufficient adhesion between the patterns and substrates has significantly limited their utility and reliability. Here, the surface-embedded graphene patterns were directly deposited on polydimethylsiloxane (PDMS) surfaces without hydrophilic treatment via the embedded droplet printing (EDP). The viscous PDMS films instead of the solid ones were used as substrates, and the graphene patterns were partly embedded onto the viscous PDMS surfaces. To assess the adhesion performance, a series of tests were performed. In the bending and tensile tests, the patterns strongly adhered to the PDMS films. Further, the patterns had a favorable increase in resistance in the tensile strain range of 0–3.5%. The resistance of the surface-embedded graphene patterns exhibited a negligible change for over 3 min in the ultrasonic bath. Finally, the relative resistance R/R0 remained constant after the first two adhesion tests using a 3M tape. The surface-embedded graphene patterns exhibited a strong adhesion to the flexible/stretchable substrates, indicating the application prospect in the field of flexible devices.

Polarization Sensitive Imaging with Qubits

We compare reconstructed quantum state images of a birefringent sample using direct quantum state tomography and inverse numerical optimization technique. Qubits are used to characterize birefringence in a flat transparent plastic sample by means of polarization sensitive measurement using density matrices of two-level quantum entangled photons. Pairs of entangled photons are generated in a type-II nonlinear crystal. About half of the generated photons interact with a birefringent sample, and coincidence counts are recorded. Coincidence rates of entangled photons are measured for a set of sixteen polarization states. Tomographic and inverse numerical techniques are used to reconstruct the density matrix, the degree of entanglement, and concurrence for each pixel of the investigated sample. An inverse numerical optimization technique is used to obtain a density matrix from measured coincidence counts with the maximum probability. Presented results highlight the experimental noise reduction, greater density matrix estimation, and overall image enhancement. The outcome of the entanglement distillation through projective measurements is a superposition of Bell states with different amplitudes. These changes are used to characterize the birefringence of a 3M tape. Well-defined concurrence and entanglement images of the birefringence are presented. Our results show that inverse numerical techniques improve overall image quality and detail resolution. The technique described in this work has many potential applications.

Design and Clinical Application Effect Analysis of a New Type of Oral Fluid Suction Device for Patients with Orotracheal Intubation.

Tracheal intubation is an important access to general anesthesia surgery or respiratory support in critically ill patients. Orotracheal intubation is the most common method of establishing artificial airways in clinical practice. Tracheal intubation and mechanically assisted breathing are among the important steps in the clinical rescue of critically ill patients. During tracheal intubation, it easily causes iatrogenic skin damage, unclear mouth, ulcer, and other oral mucosal complications due to the improper fixation method and excellent dental pads. Therefore, the purpose of this study was to design a novel oral suction device for patients with orotracheal intubation and explore its safety, convenience, and comfort in the clinical application of orotracheal intubation patients. From October 2016 to April 2017, a total of 232 patients with mechanical ventilation through orotracheal intubation in the Department of Surgery and Critical Care Medicine were selected by the convenience sampling method. According to the random number table method, 232 cases were divided into the experimental group and control group, with 116 cases in each group. The experimental group used a self-designed oral fluid suction device to fix the tracheal intubation; the control group used the traditional method, placing ordinary disposable tooth pads, and then using 3M tape to fix the tracheal intubation. The incidence of oral mucosa and lip pressure ulcers, patient comfort, and tracheal tube displacement were observed and compared between the two groups. The incidence of oral mucosa and lip pressure ulcers in the observation group using the self-designed oral fluid suction device to fix the tracheal intubation was significantly lower than that in the control group. At the same time, the comfort of the patients was significantly higher than that of the control group, the incidence of tracheal tube displacement was significantly lower than that of the control group, and the differences between the above indicators were statistically significant (P < 0.05). For patients with orotracheal intubation, using a new oral fluid suction device to fix the tracheal intubation can effectively prevent the displacement of the tracheal intubation, protect the oral mucosa and lips, and reduce the pain of the patient. At the same time, the oral fluid suction device designed in this study has low production cost, strong practicability, and is suitable for clinical promotion.

Structural Design and Property Study on Flexible Electronic Films with High Heat Resistance and Friction Durability

AbstractTo improve both thermal stability and friction durability of flexible electronic films with nano‐Ag, a series of flexible films with dendric nano‐Ag embedded into high thermally stable 2‐adamantane containing poly(aryl ether ketone) (2‐ADMPEK, PAEK) substrates are prepared in this work. These films are named as PAEK‐dnAg. The dendric nanostructure of Ag conductive layer performs excellent conductivity with sheet resistance as low as 0.3959 Ω ◻−1. The wide‐angle X‐ray diffraction and scanning electron microscope (SEM) results show dendric nano‐Ag layer well incorporated to PAEK substrates. The results of thermal stability, hydrolysis–oxidation test, adhesion test, and friction durability indicate the PAEK substrate can effectively protect dendric nanosilver conductive layer from heat, harsh oxidation, and friction. The SEM images further show the dendric embedded structure can remain almost unchanged after high temperature (400 °C) heating in air, water boiling oxidation for 12 h, 2500‐cycle 3M tape peeling test, and harsh friction with sanding paper under 5 N, which should lead to the excellent durability of PAEK‐dnAg samples in harsh condition. Thus, PAEK‐dnAgs may show great potential in flexible electronic films application for harsh condition such as high temperature, hydrothermal environment or high friction.

USO DE PROTETORES BUCAIS EM PACIENTES INTUBADOS NA UNIDADE DE TERAPIA INTENSIVA: UMA REVISÃO DE LITERATURA

Intubation is a medical technique that consists of placing a tube inside the trachea, orally or nasally, with the aim of maintaining definitive control of the airway. However, there may be complications such as laceration of the lips and gums, vocal fold avulsion, fracture and tooth avulsion. This literature review therefore aims to report the damage that is caused to dental structures, the factors that increase the risk of trauma in the intubation process and the methods that are used to prevent them. A literature review was performed through a search for articles in the Medline/PubMed database including 10 articles. Based on the analysis of the articles included, it can concluded that the use of mouthguards, whether they are 3M tape, wooden spatulas, or mouthguards molded by dentists, can significantly reduce the forces that act on the teeth, minimizing the risks of dental trauma. Thermoplastics have their effectiveness discussed in different studies, but the most recent one discusses that they are effective, in addition to being easy to handle and cost-effective, but it is not the most recommended method of protection.

KN95 filtering facepiece respirators distributed in South Africa fail safety testing protocols

Background . Given the global shortage of N95 filtering facepiece respirators (FFP2 in Europe) during the COVID-19 pandemic, KN95 masks (Chinese equivalent of the N95 and FFP2) were imported and distributed in South Africa (SA). However, there are hardly any published independent safety data on KN95 masks. Objectives. To evaluate the seal, fit and filtration efficiency of several brands of KN95 masks marketed for widespread use in SA healthcare facilities, using standardised testing protocols. Methods . The verifiability of manufacturer and technical details was first ascertained, followed by evaluation of the number of layers comprising the mask material. The testing protocol involved a directly observed positive and negative pressure user seal check, which if passed was followed by qualitative fit testing (sodium saccharin) in healthy laboratory or healthcare workers. Quantitative fit testing (3M) was used to validate the qualitative fit testing method. The filtration efficacy and integrity of the mask filter material were evaluated using a particle counter-based testing rig utilising aerosolised saline (expressed as filtration efficacy of 0.3 µm particles). Halyard FLUIDSHIELD 3 N95 and 3M 1860 N95 masks were used as controls. Results . Twelve KN95 mask brands (total of 36 masks) were evaluated in 7 participants. The mask type and manufacturing details were printed on only 2/12 brands (17%) as per National Institute of Occupational Safety and Health and European Union regulatory requirements. There was considerable variability in the number of KN95 mask layers (between 3 and 6 layers in the 12 brands evaluated). The seal check pass rate was significantly lower in KN95 compared with N95 masks (1/36 (3%) v. 12/12 (100%); p&lt;0.0001). Modification of the KN95 ear-loop tension using head straps or staples, or improving the facial seal using Micropore 3M tape, enhanced seal test performance in 15/36 KN95 masks evaluated (42%). However, none of these 15 passed downstream qualitative fit testing compared with the control N95 masks (0/15 v. 12/12; p&lt;0.0001). Only 4/8 (50%) of the KN95 brands tested passed the minimum filtration requirements for an N95 mask (suboptimal KN95 filtration efficacy varied from 12% to 78%, compared with 56% for a surgical mask and &gt;99% for the N95 masks at the 0.3 µm particle size). Conclusions . The KN95 masks tested failed the stipulated safety thresholds associated with protection of healthcare workers against airborne pathogens such as SARS-CoV-2. These preliminary data have implications for the regulation of masks and their distribution to healthcare workers and facilities in SA.

KN95 filtering facepiece respirators distributed in South Africa fail safety testing protocols.

Given the global shortage of N95 filtering facepiece respirators (FFP2 in Europe) during the COVID-19 pandemic, KN95 masks (Chinese equivalent of the N95 and FFP2) were imported and distributed in South Africa (SA). However, there are hardly any published independent safety data on KN95 masks. To evaluate the seal, fit and filtration efficiency of several brands of KN95 masks marketed for widespread use in SA healthcare facilities, using standardised testing protocols. The verifiability of manufacturer and technical details was first ascertained, followed by evaluation of the number of layers comprising the mask material. The testing protocol involved a directly observed positive and negative pressure user seal check, which if passed was followed by qualitative fit testing (sodium saccharin) in healthy laboratory or healthcare workers. Quantitative fit testing (3M) was used to validate the qualitative fit testing method. The filtration efficacy and integrity of the mask filter material were evaluated using a particle counter-based testing rig utilising aerosolised saline (expressed as filtration efficacy of 0.3 µm particles). Halyard FLUIDSHIELD 3 N95 and 3M 1860 N95 masks were used as controls. Twelve KN95 mask brands (total of 36 masks) were evaluated in 7 participants. The mask type and manufacturing details were printed on only 2/12 brands (17%) as per National Institute of Occupational Safety and Health and European Union regulatory requirements. There was considerable variability in the number of KN95 mask layers (between 3 and 6 layers in the 12 brands evaluated). The seal check pass rate was significantly lower in KN95 compared with N95 masks (1/36 (3%) v. 12/12 (100%); p&lt;0.0001). Modification of the KN95 ear-loop tension using head straps or staples, or improving the facial seal using Micropore 3M tape, enhanced seal test performance in 15/36 KN95 masks evaluated (42%). However, none of these 15 passed downstream qualitative fit testing compared with the control N95 masks (0/15 v. 12/12; p&lt;0.0001). Only 4/8 (50%) of the KN95 brands tested passed the minimum filtration requirements for an N95 mask (suboptimal KN95 filtration efficacy varied from 12% to 78%, compared with 56% for a surgical mask and &gt;99% for the N95 masks at the 0.3 µm particle size). The KN95 masks tested failed the stipulated safety thresholds associated with protection of healthcare workers against airborne pathogens such as SARS-CoV-2. These preliminary data have implications for the regulation of masks and their distribution to healthcare workers and facilities in SA.

Mechanical Hardness and Adhesion Property of Surface-Polymerized Nanocomposites based on Polyaniline and Sol-Gel Silica

We have investigated the mechanical hardness and adhesion property of electrically conductive polyaniline (PANI) and polyaniline/silane composites prepared on a glass substrate by using a simple polymerization and deposition method. The formation of the conducting nanocomposites was verified by spectroscopic analyses and electron microscopy imaging. The polyaniline films formed in the presence of (3-aminopropyl)triethoxysilane (APTES) were observed to exhibit a remarkable enhancement in their hardness. The nanoindentation study showed that, as the concentration of APTES was increased from 0 to 66.7 wt%, the loading required for a displacement of 25 nm increased from 0.1 to 10.1 µN. Improved adhesion was observed even after 10 peel-off test cycles using commercially available 3M tape. A comparison between the silane materials showed that APTES, owing to the presence of catalytic amine groups, formed more robust composites than tetraethyl orthosilicate (TEOS) under the given processing conditions. The results of our study demonstrate that mechanically rugged polyaniline/silane composite films can be used as pH sensors.

P‐68: Research of Metal Trace Adhesion on Organic Film for Touch Panel

In this paper, the metal adhesion of metal trace structure and line‐width size on the organic film (insulating OC material) for touch panel was studied. At present, pure aluminum and pure copper processes can achieve the low cost and high performance requirements of the touch panel design. The influencing factors of pure aluminum trace’s adhesion on organic film were studied: ➀there was no significant difference in the comparative pull‐out force between OC and inorganic film on the 3M tape used for cross‐cut test; ➁the stress directivity of the organic film and the inorganic film was tested on silicon wafer, and the adhesion mechanism was analyzed;➂ the effect of different line widths and structure on adhesion was test; ➃in order to achieve the adhesion of metal trace in the touch panel (≧4B), it is necessary to optimize the structure designed of the organic insulating layer and SiNxOy layer.

Sol⁻Gel-Processed Organic⁻Inorganic Hybrid for Flexible Conductive Substrates Based on Gravure-Printed Silver Nanowires and Graphene.

In this study, an organic–inorganic (O–I) nanohybrid obtained by incorporating an alkoxysilane-functionalized amphiphilic polymer precursor into a SiO2–TiO2 hybrid network was successfully utilized as a buffer layer to fabricate a flexible, transparent, and stable conductive substrate for solution-processed silver nanowires (AgNWs) and graphene under ambient conditions. The resulting O–I nanohybrid sol (denoted as AGPTi) provided a transmittance of the spin-coated AgNWs on an AGPTi-coated glass of 99.4% and high adhesion strength after a 3M tape test, with no visible changes in the AgNWs. In addition, AGPTi acted as a highly functional buffer layer, absorbing the applied pressure between the conductive materials, AgNWs and graphene, and rigid substrate, leading to a significant reduction in sheet resistance. Furthermore, gravure-printed AgNWs and graphene on the AGPTi-based flexible substrate had uniform line widths of 490 ± 15 and 470 ± 12 µm, with 1000-cycle bending durabilities, respectively.