Polycarbonate Surface Research Articles

A low-pollution surface modification system for improving the adhesion of polycarbonate

In the present study, the surface adhesion capacity of polycarbonate (PC) has been improved by using a low-pollution surface modification system that includes alkaline potassium ferrate (K2FeO4). The effects of environmentally friendly swelling conditions, NaOH and K2FeO4 contents, and other modification conditions on the PC surface topography, hydrophilicity, and surface roughness were then primarily studied. The modification resulted in an improvement of the hydrophilic property of the PC surface. There was a significant reduction in the surface contact angle from 97.6° to 34.1°. A considerable increase in the PC surface’s average surface roughness (Ra) was also observed, which increased from 2 nm to 209 nm. Meanwhile, after chemical copper plating, the maximum peel strength between the PC resin and copper layer reached 1.13 kN/m. Furthermore, infrared absorption spectroscopy (FT–IR) and X–ray photoelectron spectroscopy (XPS) was used in the analyses of the surface chemical structure of the PC substrate, both prior to and after surface treatments. The results indicated that the modification of the surface led to increased hydrophilic groups on the PC surface, which was advantageous for the subsequent PC treatments (involving chemical copper plating). In short, the PC surface modification increased surface roughness and surface hydrophilicity, which improved the bonding between the chemically plated copper layer and the PC substrate.

Dual First and Second Surface Solar Mirrors of Polished WS2 and Silver by Dynamical Chemical Plating Technique on Polycarbonate.

This work proposes for the first time protecting-reflecting on both sides of plated mirrors and a solution to polycarbonate surface vulnerability to weathering and scratching using tungsten disulfide (WS2) by mechanical polishing. The ability of the dynamic chemical plating (DCP) technique to deposit Ag films at the nanometer scale on a polycarbonate (PC) substrate and its characteristics to be metallized is also shown. These deposits hold significant promise for concentrated solar power (CSP) applications. Complementarily, the application of WS2 as a reflective film for CSP by mechanical polishing on smooth polycarbonate surfaces is both novel and practical. This technique is innovative and scalable without needing reactants or electrical potential, making it highly applicable in real-world scenarios, including, potentially, on-site maintenance. The effects of surface morphology and adhesion, and the reflectivity parameters of the silver metallic surfaces were investigated. Wettability was investigated because it is important for polymeric surfaces in the activation and metal deposition immediately after redox reactions. The flame technique improved wettability by modifying the surface with carbonyl and carboxyl functional groups, with PC among the few industrial polymers that resisted such a part of the process. The change in the chemical composition, roughness, and wettability of the surfaces effectively improved the adhesion between the Ag film and the PC substrate. However, it did not significantly affect the adhesion between PC and WS2 and showed its possible implementation as a first surface mirror. Overall, this work provides a scalable, innovative method for improving the durability and reflectivity of polycarbonate-based mirrors, with significant implications for CSP applications.

Molding Process Retaining Gold Nanoparticle Assembly Structures during Transfer to a Polycarbonate Surface.

The immobilization of gold nanoparticle (AuNP) linear surface assemblies on polycarbonate (PC) melt surface via molding is investigated. The order of the particle assemblies is preserved during the molding process. The assemblies on PC exhibit plasmonic coupling features and dichroic properties. The structure of the assemblies is quantified based on Scanning Electron Microscopy (SEM) and image analysis data using an orientational order parameter. The transfer process from mold to melt shows high structural fidelity. The order parameter of around 0.98 reflects the orientation of the lines and remains unaffected, independent of the injection direction of the melt relative to the particle lines. This is discussed in the frame of fountain flow during injection molding. The particles were permanently fixed and withstood the injection molding process, detachment of the substrate, and extraction in boiling ethanol. The plasmonic particles coupled strongly within the dense nanoparticle lines to produce anisotropic optical properties, as quantified by dichroic ratios of 0.28 and 0.52 using ultraviolet-visible-near-infrared (UV-Vis-NIR) spectroscopy. AuNP line assemblies on a polymer surface may be a basis for plasmonic devices like surface-enhanced Raman scattering (SERS) sensors or a precursor for nanowires. Their embedding via injection molding constitutes an important link between particle-self-assembly approaches for optically functional surfaces and polymer processing techniques.

Multifractal detrended fluctuation analysis on the fracture surface of polycarbonate and acrylonitrile-butadiene-styrene alloy

Multifractal detrended fluctuation analysis (MF-DFA) has been carried out to evaluate the multifractal properties of the fracture morphology for Polycarbonate (PC) and Acrylonitrile-butadiene-styrene (ABS) alloy, and the relationship between the long-range correlation parameter of the samples fracture - Hurst exponent and fractal dimension was explored and analyzed. The results suggest that the existence of multifractal properties within the micrometer scale domain we investigated for the fracture surface of PC/ABS alloy samples. The Hurst exponent and fractal dimension can both be used to measure and characterize the fracture surface morphology of the PC/ABS alloys. As the content of compatibilizer PP-g-MAH increased, the tensile strength of PC/ABS alloy decreased, the fracture surface peaks tend to dominate, the Hurst exponent increased, the fractal dimension decreased, and its strength retention rate increases, displaying persistence.

Reinventing waste: Transforming discarded optical discs into polycarbonate-organosilane adsorbent for effective removal of mercury(II) in water

Polycarbonate, renowned for its versatile properties, has become indispensable in numerous domestic applications. However, the escalating rates of consumption and disposal raise significant concerns for sustainable development. Of particular concern is the inadequate management of obsolete optical discs, which pose a serious environmental threat due to the non-biodegradable polycarbonate component. To address this challenge, this study aimed to repurpose polycarbonate derived from optical disc waste into adsorbent materials using 3-aminopropyl triethoxysilane (APTES) coupling. The waste-derived products underwent comprehensive characterization employing Fourier transform infrared spectroscopy, field emission-scanning electron microscopy, energy dispersive X-ray spectroscopy, Brunauer-Emmett-Teller, and Barrett-Joyner-Halenda techniques. Additionally, batch experiments were conducted to evaluate the mercury(II) adsorption behaviours. The successful immobilisation of APTES on polycarbonate surfaces was confirmed by the detection of nitrogen, silicon, and urethane groups. Notably, the product modified with 3 mL of APTES exhibited the highest surface area (61.992 m2 g−1), suggesting its potential for the adsorptive removal of mercury(II). Analysis based on the Langmuir (R2 =0.9824) and Redlich-Peterson (R2 =0.9834) isotherm models suggested a predominantly monolayer adsorption mechanism with an estimated maximum capacity of 1.284 mg g–1, while the adsorption process followed pseudo second-order kinetics (R2 =0.9998). The results highlight the efficacy of waste-derived polycarbonate-organosilane adsorbents in removing mercury(II) from diverse water matrices, rendering them attractive from both economic and environmental sustainability perspectives.

Tailoring polycarbonate surfaces for improved Ge film adhesion: The role of plasma treatments in 50:50 O2/Ar atmospheres

Polycarbonate (PC) substrates were exposed to plasma environments consisting of a 50:50 mixture of oxygen and argon, and were subsequently coated with germanium (Ge) films grown via sputtering. The hydrophilicity of the PC surfaces was tailored by ion bombardment with energy levels ranging from 50 to 300 eV, which led to a reduction in water contact angles from a native 80° to a superhydrophilic state. Analyses of chemical composition and structure of the PC were performed using X-ray Spectroscopy (XPS) and Fourier Transform Infrared Spectroscopy in Attenuated Total Reflectance geometry (FTIR-ATR), and then correlated to the adhesion of the Ge thin films. Optimal adhesion of the Ge films was achieved by bombarding the PC with ions at energies between 100 and 200 eV, activating the polymer surface while avoiding photodegradation as confirmed by chemical analysis. We report an efficient method for achieving superhydrophilicity of PC within a short treatment time of 60 s that can be effectively integrated in diverse vacuum applications.

Adhesion of electron-beam evaporated SiO2/TiO2 anti-reflective coating on ion-treated polycarbonate substrate under xenon arc accelerated weathering test

Anti-reflective (AR) coatings on polymer substrates enhance light transmittance and minimize reflectance loss. However, durability of multi-layered AR coatings on polymer substrates under various weathering conditions (temperature, radiation, and humidity) can be challenging and affecting adhesion of the coating to the substrate. Therefore, in the present work, Xenon arc accelerated weathering test followed ISO 16474 guidelines was used to investigate durability of electron-beam evaporated SiO2/TiO2 stacking layer as the AR coating on an ion-treated polycarbonate (PC) substrate by varying anode voltage of the ion treatment, oxygen flow rate during the treatment, and thickness of a binding layer (Chromium-based alloy) sandwiched between AR coating and PC substrate. Crosshatch tape test based on ASTM D3359 was used to evaluate the adhesion performance. Physical changes of ion-treated PC surface were characterized by atomic force microscopy and scanning electron microscopy, whereas Fourier transform infrared spectroscopy was adopted to identify chemical functional groups on the treated PC surface. Residual stress and optical reflection of AR coating on the PC were measured by laser interferometry and UV–Vis spectrophotometry, respectively. As anode voltage increased with no oxygen flow, average surface roughness of PC increased but the roughness decreased as oxygen flow rate increased when the highest anode voltage (100 V) was applied. A reversed trend of the roughness achieved with the lowest anode voltage (80 V). Amount of C–O functional group on treated PC increased when the average surface roughness decreased. The adhesion improved by incorporating a binding layer, depending on anode voltage and oxygen flow rate, that can alter residual compressive stress of the material system, reduce moisture and UV attack without sacrificing optical performance of the AR coating. Generally, a better AR coating adhesion can be achieved with smoother PC surface having higher amount of C–O bonding, and higher overall residual compressive stress.

Improvement of water and gas barrier properties of polycarbonate by the SiOx plasma treatment

The purpose of this research paper was to improve the water and gas barrier properties of polycarbonate (PC) by the deposition of organosilicon thin films through radio-frequency plasma treatment. For optimization, different treatment parameters (namely, the discharge power, the deposition time, and the ratio q between O2 and hexamethyldisiloxane) were varied. The influence of the plasma coating of low thickness (30–308 nm) on the surface and structure properties of PC and on its thermal stability was analyzed. The resistance toward gases (N2, O2, CO2) and water was investigated through permeation measurements. The results have shown that increasing the ratio q from 5 to 12.5 allows obtaining a layer of more inorganic nature and a O/Si ratio close to 2 enhances the PC thermal stability. It has been found that the barrier properties of the treated PC film mainly depend on the morphology of the deposited coating, its homogeneity and the surface wettability. For instance, with q = 7.5 leading to the less hydrophilic and more homogeneous treated surface, the barrier effect significantly increased, as the obtained barrier improvement factor was ∼ 60 % for gases and 24 % for water.

Super-hydrophilic nano-structured surface with antibacterial properties

Adhesion of bacteria to a surface followed by biofilm formation causes many problems in human health care and, in some cases, can even cause human death. Therefore, reducing bacterial attachment to surfaces and antibacterial surface fabrication are two of the most important issues in many applications, including healthcare, medical, food packaging, etc. Polycarbonate (PC) is one of the most widely used polymers in medicine. However, it does not have antibacterial properties. On the other hand, laser treatment is used as a standard method for surface modification of different materials. In this paper, excimer laser irradiation at a fluence below the ablation threshold was used for surface patterning and modification of the polycarbonate sample, aiming to improve its antibacterial properties. The results show that super-hydrophilic nanostructured polycarbonate surfaces have antibacterial properties compared to non-treated PC, which has no antibacterial properties.

Study of surface etching of polycarbonate by environmentally friendly alkaline potassium permanganate system

This study examined the surface etching of polycarbonate (PC) using an environmentally friendly etching technique and an alkaline potassium permanganate system. On the surface morphology and roughness, the impacts of swelling circumstances, KMnO4-NaOH concentration, etching temperature, and time were examined. The PC substrate's average surface roughness (Ra) was enhanced by the etching process from 4 nm to 253 nm. The peel strength between the chemically coated copper film and the PC substrate also reached 0.91 KN/m. Using contact angle, Fourier transforms infrared spectrum (FT-IR), and X-ray photoelectron spectroscopy (XPS), the surface chemical structure of the PC substrate was compared before and after treatment. The PC surface turned hydrophilic after the etching process, and the contact angle dropped from 97.2° to 33.2°. The etching process increased the PC surface's roughness and hydrophilicity, which enhanced the adhesion strength between the polycarbonate (PC) substrate and the chemically coated copper film, according to FT-IR absorption spectroscopy, Atomic Force Microscope (AFM) and XPS analysis.

Methods for virus recovery from environmental surfaces to monitor infectious viral contamination

Accurate quantification of infectious contaminants on environmental surfaces, particularly infectious viruses, is essential for contact transmission risk assessment; however, difficulties in recovering viruses from surfaces using swabs complicates this quantification process. Herein, we identified the factors that significantly affected virus recovery rates and developed an ideal swab method that yielded the highest rate of virus recovery. We comprehensively analyzed the effects of swab type (cotton/polyester), swab water content (wet/dry conditions), surface material, and surface area on the rates of viral RNA and infectious virus recovery.The virus recovery rate was significantly lower than the viral RNA recovery rate (P < 0.01), indicating difficulty in the quantification of infectious viruses. The virus recovery rate was significantly higher under wet conditions than that under dry conditions (P < 0.006), and the virus recovery rate obtained using cotton swabs was significantly higher than that using polyester swabs (P < 0.0001). Furthermore, the virus recovery rate had a strong negative correlation (correlation coefficient >0.8) with the target surface area. The maximum surface area where the virus recovery rate was ≥10% (MSA-10%) was identified as the maximum quantifiable area. For influenza virus recovery, MSA-10% on polyvinyl chloride (PVC) sheet, PVC leather, stainless steel, silicone, glass, and polycarbonate surfaces was 66.7, 193, 60.2, 144, 105, and 15.6 cm2, respectively. For feline calicivirus recovery, MSA-10% on PVC sheet, PVC leather, stainless steel, silicone, glass, and polycarbonate surfaces was 210, 111, 2120, 250, 322, and 180 cm2, respectively.The most accurate and ideal method for quantifying infectious viruses on environmental surfaces with the highest recovery rates meets three specifications: “wet conditions,” “the use of cotton swabs,” and “a target surface area of approximately 10 cm2.

Weldability improvement of immiscible polycarbonate/GFRP by femtosecond laser surface treatment

Poor miscibility is an important reason for the non-weldable performance of most dissimilar polymers and their composites, and traditional surface treatments cannot effectively improve the weldability of dissimilar polymers. Therefore, the non-weldability of dissimilar polymers is one of the important factors that limit the application of polymers and their composites. We proposed a surface modification scheme of laser ablation or etching to improve the weldability of immiscible polymers effectively. Experimental studies on femtosecond ultraviolet (UV) laser ablation/etching, mid-infrared laser transmission welding (LTW), and related characterization and mechanical tests were carried out. The experimental results showed that laser ablation induced the deposition of abundant polar oxygen-containing groups on the surface of polycarbonate (PC), which improved the miscibility of PC and polyamide 66 with a glass fibre volume ratio of 30% (PA66GF30) and reduced the weak boundary layer (WBL), thereby improving their chemical bonding performance. Using the compatibilization mechanism induced by laser ablation, the bonding strength of the PC/PA66GF30 joint obtained by LTW was 13.7 MPa, which was much higher than that of the untreated joint (1.4 MPa). However, the grooves generated by laser etching could induce macro-anchoring effect of the hybrid joint. Based on the compatibilization mechanism and macro-anchoring effect, with the selection of appropriate welding power and etching parameters, the bonding strength of the PC/PA66GF30 joint was further increased to 29.7 MPa. This work has demonstrated the feasibility of laser surface treatment (especially etching) to significantly improve the welding strength of immiscible polymers and their composites.

A New In Vitro Blood Flow Model for The Realistic Evaluation of Antimicrobial Surfaces.

Device-associated bloodstream infections can cause serious medical problems and cost-intensive post-infection management, defining a need for more effective antimicrobial coatings. Newly developed coatings often show reduced bacterial colonization and high hemocompatibility in established in vitro tests, but fail in animal studies or clinical trials. The poor predictive power of these models is attributed to inadequate representation of in vivo conditions. Here, we present a new single-pass blood flow model, with simultaneous incubation of the test surface with bacteria and freshly-drawn human blood. The flow model is validated by comparative analysis of a recently developed set of anti-adhesive and contact-killing polymer coatings, and the corresponding uncoated polycarbonate surfaces. The results confirm the model's ability to differentiate the antimicrobial activities of the studied surfaces. Blood activation data correlate with bacterial surface coverage: low bacterial adhesion is associated with low inflammation and hemostasis. Shear stress correlates inversely with bacterial colonization, especially on anti-adhesive surfaces. The introduced model is concluded to enable the evaluation of novel antimicrobial materials under in vivo-like conditions, capturing interactions between bacteria and biomaterials surfaces in the presence of key components of the ex vivo host response. This article is protected by copyright. All rights reserved.

Plasma etching of polycarbonate surfaces for improved adhesion of Cr coatings

Polymers are widely used across multiple industries due to their distinct properties such as low density, tunable flexibility, ease of manufacture, and cost-effectiveness. The metallization of polymers by chromium (Cr) coatings allows such parts to replace decorative metal parts in the automotive industry. Good quality metallized polymer surfaces, however, are challenging to obtain. Several properties of the metal layers must be guaranteed, such as good adhesion, low pinhole and crack defect densities, high brightness, and intrinsic silver color. To overcome these challenges, different plasma etching treatments have been performed on polycarbonate (PC) substrates before the magnetron sputtering deposition of Cr coatings. Parameters such as bias voltage, pressure, and etching time were varied. The best plasma etching treatments in Ar atmosphere significantly improved the Cr coating quality.

ATOMIC FORCE MICROSCOPY OF ANTIBACTERIAL COATINGS PRODUCED FROM POLYCATION AND ITS WATER-SOLUBLE COMPLEX WITH POLYANION

In this work, the morphology and stability of coatings formed from polydiallyldimethylammonium chloride, as well as its complex with sodium polystyrenesulfonate, on the surface of glass and polycarbonate were studied. It has been established that the modifi cation of a polycation with a polyanion makes it possible to increase the resistance of the formed coatings to washing off with water, ensuring the creation of effective antibacterial coatings on various surfaces.

Use of a commercially available hydrogel as a novel DNA surface sampling tool.

A common requirement in the military, law enforcement, and forensic mission space is the need to collect trace samples from surfaces using a method that not only readily captures the sample but also retains its integrity for downstream identification and characterization. Additionally, collecting samples from three-dimensional objects (e.g., shell casings) is a challenge for which there is currently no validated standardized approach. Recently, hydrogels have been shown to have the potential for surface collection of trace bacterial spores, amino acids, and DNA. To test whether these hydrogels can serve as a viable collection medium for sampling DNA from surfaces, we carried out a series of preliminary tests examining collection efficiency and suitability of hydrogel material to recover samples of diluted, dried human DNA on a smooth polycarbonate surface. The recovery of surface DNA using a commercially available hydrogel was examined, and the efficiency compared to samples collected using a standard foam collection swab. DNA collected using the hydrogel and swab methods was then examined using quantitative polymerase chain reaction (qPCR) and short tandem repeat (STR) analysis to determine whether the collection material was compatible with these downstream processes. The hydrogel material used for this study collected the experimental DNA with comparable efficiency to standard collection swabs. In addition, qPCR and STR analyses demonstrated compatibility with the hydrogel collection and extraction process. These data suggest that hydrogels have the potential to be used as sample collection materials and deserve further characterization to elucidate their utility in collection from irregularly shaped, three-dimensional surfaces/materials.

WATER-SOLUBLE INTERPOLYELECTROLYTE COMPLEX BASED ON POLY(DIALLYLDIMETHYLAMMONIUM CHLORIDE) AND SODIUM POLYACRYLATE AS A COMPONENT FOR CREATING STABLE BIOCIDAL COATINGS

Polycation-based coatings represent a promising class of protective antimicrobial coatings. Water-soluble complexes of poly(diallyldimethylammonium chloride) (PDADMAC) with sodium polyacrylate (PANa) have been studied by turbidimetry. It has been shown that the addition of the polyanion (12 mol %) to the polycation leads to the formation of an interpolyelectrolyte complex (IPEC) stable with respect to phase separation in water-salt media with salt concentrations as high as 0.1–0.2 M. In contrast to the traditional method of obtaining coatings from IPEC by layer-by-layer deposition, we have studied the preparation of the coatings directly from a solution of water-soluble IPEC on a hydrophilic glass surface and a surface of more hydrophobic polycarbonate. It has been found that the formation of IPEC makes it possible to increase the resistance of the coating to wash-off with water compared to the individual PDADMAC coating on both types of substrates.

Engineering Large-Area Antidust Surfaces by Harnessing Interparticle Forces.

Dust accumulation is detrimental to optical elements, electronic devices, and mechanical systems and is a significant problem in space missions and renewable energy deployment. In this paper, we report the demonstration of antidust nanostructured surfaces that can remove close to 98% of lunar particles solely via gravity. The dust mitigation is driven by a novel mechanism, whereby particle removal is facilitated by the formation of particle aggregates due to interparticle forces, allowing the particles to be removed in the presence of other particles. The structures are fabricated using a highly scalable nanocoining and nanoimprint process, where nanostructures with precise geometry and surface properties are patterned on polycarbonate substrates. The dust mitigation properties of the nanostructures have been characterized using optical metrology, electron microscopy, and image processing algorithms to demonstrate that the surfaces can be engineered to remove nearly all of the particles above 2 μm in size in the presence of Earth's gravity. Compared to the 35.0% area coverage on a smooth polycarbonate surface, the particle coverage on nanostructures with 500 nm period is significantly reduced to 2.4%, an improvement of 93%. This work enhances the understanding of the particulate adhesion on textured surfaces and demonstrates a scalable, effective solution to antidust surfaces that can be broadly applied to windows, solar panels, and electronics.

Carbonate-Terminated Self-Assembled Monolayers for Mimicking Nanoscale Polycarbonate Surfaces

Two carbonate-terminated alkanethiol molecules having different positional isomers of a six-membered cyclic carbonate group, 3-COC12SH and 2-COC12SH, were synthesized and used to generate self-assembled monolayers (SAMs) on gold to serve as mimics of the surfaces of commercially available poly(propylene carbonate) (PPC) and poly(ethylene carbonate) (PEC). The adsorbate molecules were characterized using 1H and 13C nuclear magnetic resonance spectroscopy and high-resolution mass spectrometry. The corresponding SAMs on gold were characterized by ellipsometry, contact angle goniometry, polarization-modulation infrared reflection-adsorption spectroscopy, and X-ray photoelectron spectroscopy. The contact angle data showed that the wettabilities of both SAMs were largely similar to each other and to the PEC samples for a wide range of contacting probe liquids (with water correlating particularly well with PEC and both SAMs). As a whole, the wettability data suggest that the carbonate-terminated SAMs can serve as mimics of nanoscale polycarbonate surfaces and can be used to investigate the interfacial properties of polycarbonates without interference from the surface reconstruction.

Towards understanding the surface rippling process by periodic reciprocal nanoscratching

The bundle structure formed perpendicular to the scratching direction is a type of wear-induced structure for thermoplastics. In this study, the formation mechanism of bundle structures on polycarbonate (PC) surfaces is investigated by reciprocal scratching experiments. Based on the analysis of the morphologies, friction forces, and height signals, the formation of the bundle structure is reproduced. The influence of scratching parameters, including the feed value and scratching direction, on the formation of the bundle structure is also studied. It is found that the bundle structure is accumulated by the continuous stacking of the sample materials plowed by the tip in stick—slip motion, and that the stick—slip behavior is enhanced with increased scratching times. This work reproduces the formation process of bundle structure in experiments for the first time and demonstrates that the stick—slip enhancement mechanism exists in the reciprocal scratching process, providing further insight into the friction behavior of polymers.