Surface Modification Of Polymers Research Articles

Double Electrode Experiments Reveal the Processes Occurring at PEDOT-Coated Neural Electrode Arrays.

Neural electrodes have recently been developed with surface modifications of conductive polymers, in particular poly(3,4-ethylenedioxythiophene) (PEDOT), and extensively studied for their roles in recording and stimulation, aiming to improve their biocompatibility. In this work, the implications for the design of practical neural sensors are clarified, and systematic procedures for their preparation are reported. In particular, this study introduces the use of in vitro double electrode experiments to mimic the responses of neural electrodes with a focus on signal-recording electrodes modified with PEDOT. Specifically, potential steps on one unmodified electrode in an array are used to identify the responses for PEDOT doped with different anions and compared with that of a bare platinum (Pt) electrode. The response is shown to be related to the rearrangement of ions in solution near the detector electrode resulting from the potential step, with a current transient seen at the detector electrode. A rapid response for PEDOT doped with chloride (ca. 0.04 s) ions was observed and attributed to the fast movement of chloride ions in and out of the polymer film. In contrast, PEDOT doped with poly(styrenesulfonate) (PSS) responds much slower (ca. 2.2 s), and the essential immobility of polyanion constrains the direction of current flow.

Nanozyme-catalyzed oxygen self-supplying mitochondria-targeting nanoplatform for precise photodynamic therapy

Local hypoxia in tumors poses significant challenges to the effectiveness of oxygen-dependent photodynamic therapy (PDT). Herein, a versatile mitochondrial targeting and pH-responsive nanozyme platform (noted as Mito CPs-p) is developed for solving local hypoxia in tumors and enhancing the PDT efficiency. Mito CPs-p, which consists of carbon-dot-supported atomically dispersed platinum (CPs) with further surface modifications of triphenylphosphine (PPh3) and pH-responsive porphyrin polymers. The PDT of Mito CPs-p was activated in acidic tumor microenvironment and exposed platinum for catalyzing endogenous H2O2 decomposition to produce O2 at tumor sites, due to the hydrophobic-hydrophilic transition of pH-responsive porphyrin-containing polymers in Mito CPs-p from hydrophobic to hydrophilic, which can markedly enhance PDT efficiency. Besides, the rational integration of mitochondria-targeting will improve the bioavailability of reactive oxygen species and further strengthen the PDT efficiency. In vitro results indicated that Mito CPs-p has exhibited excellent mitochondrial targeting capability and the ROS yield of Mito CPs-p was dramatically amplified. In vivo data further revealed that the Mito CPs-p displayed superb therapeutic efficacy. Hence, the Mito CPs-p provides new insights for efficient PDT in hypoxia solid tumors.

Surface modification of polymers by 50 Hz dielectric barrier discharge (DBD) plasma produced in air at 40 Torr

This study deals with the surface modification of polymer films utilizing a custom designed cost- effective dielectric barrier discharge (DBD) plasma produced in air at reduced pressure. We comprehensively examine diverse aspects of surface modification, encompassing electrical discharge characterization, optical signal analysis, contact angle measurements, and surface morphology assessment. Our observations unveiled the presence of distinctive filamentary streamer-based micro-discharges during the DBD process, with a power consumption of approximately 5.64 W and an electron density of 3.4 × 1011 cm−3. Optical emission spectroscopy identifies multiple emission peaks attributed to nitrogen emissions. Notably, plasma treatment substantially reduced the water contact angle and augmented surface energy on polypropylene (PP) and polyethylene terephthalate (PET) films. Surface morphology analysis illustrated an increase in surface roughness following plasma treatment. Intriguingly, the initial rapid alterations in wettability and surface morphology attained equilibrium after approximately 30 s of treatment. This study highlights atmospheric DBD plasma's effectiveness in customizing polymer surfaces, improving wettability and roughness, offering promising applications for enhanced adhesion and wetting.

Pharmacokinetic control of orally dosed cyclosporine A with mucosal drug delivery system.

This study aimed to control the oral absorption of cyclosporine A (CsA) with the use of a mucosal drug delivery system (mDDS). Mucopenetrating nanocarriers (MP/NCs) and mucoadhesive nanocarriers (MA/NCs) were prepared by flash nanoprecipitation employing polystyrene-block-poly(ethylene glycol) and polystyrene-block-poly(N,N-dimethyl aminoethyl methacrylate), respectively. Their particle distribution in the rat gastrointestinal tract were visualized by fluorescent imaging. Plasma concentrations were monitored after oral administration of CsA-loaded MP/NCs (MP/CsA) and MA/NCs (MA/CsA) to rats. MP/NCs and MA/NCs had a particle size below 200nm and ζ-potentials of 4 and 40mV, respectively. The results from in vitro experiments demonstrated mucopenetration of MP/NCs and mucoadhesion of MA/NCs. Confocal laser scanning microscopic images showed diffusion of MP/NCs in the gastrointestinal mucus towards epithelial cells and localization of MA/NCs on the surface of the gastrointestinal mucus layer. In a pH 6.8 solution, rapid and sustained release of CsA were observed for MP/CsA and MA/CsA, respectively. After oral dosing (10 mg-CsA/kg) to rats, amorphous CsA powder exhibited a time to maximum plasma concentration (Tmax) of 3.4h, maximum plasma concentration (Cmax) of 0.12μg/mL, and bioavailability of 0.7%. Compared with amorphous CsA powder, MP/CsA shortened Tmax by 1.1 to 2.3h and increased the bioavailability by 43-fold to 30.1%, while MA/CsA prolonged Tmax by 3.4 to 6.8h with Cmax and bioavailability of 0.65μg/mL and 11.7%, respectively. These pharmacokinetic behaviors would be explained by their diffusion and release properties modulated by polymeric surface modification. The mDDS approach is a promising strategy for the pharmacokinetic control of orally administered CsA.

Modification of Polysulfide Surfaces with Low‐Power Lasers

AbstractThe modification of polymer surfaces using laser light is important for many applications in the nano‐, bio‐ and chemical sciences. Such capabilities have supported advances in biomedical devices, electronics, information storage, microfluidics, and other applications. In most cases, these modifications require high power lasers that are expensive and require specialized equipment and facilities to minimize risk of hazardous radiation. Additionally, polymer systems that can be easily modified by lasers are often complex and costly to prepare. In this report, these challenges are addressed with the discovery of low‐cost sulfur copolymers that can be rapidly modified with lasers emitting low‐power infrared and visible light. The featured copolymers are made from elemental sulfur and either cyclopentadiene or dicyclopentadiene. Using a suite of lasers with discreet wavelengths (532, 638 and 786 nm) and powers, a variety of surface modifications could be made on the polymers such as controlled swelling or etching via ablation. The facile synthesis and laser modification of these polymer systems were exploited in applications such as direct laser lithography and erasable information storage.

Modification of Polysulfide Surfaces with Low-Power Lasers.

The modification of polymer surfaces using laser light is important for many applications in the nano-, bio- and chemical sciences. Such capabilities have supported advances in biomedical devices, electronics, information storage, microfluidics, and other applications. In most cases, these modifications require high power lasers that are expensive and require specialized equipment and facilities to minimize risk of hazardous radiation. Additionally, polymer systems that can be easily modified by lasers are often complex and costly to prepare. In this report, these challenges are addressed with the discovery of low-cost sulfur copolymers that can be rapidly modified with lasers emitting low-power infrared and visible light. The featured copolymers are made from elemental sulfur and either cyclopentadiene or dicyclopentadiene. Using a suite of lasers with discreet wavelengths (532, 638 and 786 nm) and powers, a variety of surface modifications could be made on the polymers such as controlled swelling or etching via ablation. The facile synthesis and laser modification of these polymer systems were exploited in applications such as direct laser lithography and erasable information storage.

Surface Modification of Polymers by Plasma Treatment for Appropriate Adhesion of Coatings.

In this study, recent advances in tailoring the surface properties of polymers for the optimization of the adhesion of various coatings by non-equilibrium gaseous plasma are reviewed, and important findings are stressed. Different authors have used various experimental setups and reported results that scatter significantly and are sometimes contradictory. The correlations between the processing parameters and the adhesion are drawn, and discrepancies are explained. Many authors have explained improved adhesion with the adjustment of the surface free energy or wettability of the polymer substrate and the surface tension of liquids used for the deposition of thin films. The adhesion force between the polymer substrate and the coating does not always follow the evolution of the surface wettability, which is explained by several effects, including the aging effects due to the hydrophobic recovery and the formation of an interlayer rich in loosely bonded low molecular weight fragments.

Efficient Approach for Direct Robust Surface Grafting of Polyethyleneimine onto a Polyester Surface during Moulding.

This paper uses a very effective way for surface modification of thermoplastic polymers during moulding. It is based on a grafting reaction between a thin layer of a functional polymer, deposited on a substrate in advance, and a polymer melt. In this paper, a glycol-modified polyethylene terephthalate (PETG) that was brought in contact with a polyethyleneimine layer during fused filament fabrication is investigated. The focus of this paper is the investigation of the reaction product. Grafting was realised by the formation of stable amide bonds by amidation of ester groups in the main chain of a PETG. XPS investigations revealed that the conversion of amino groups was very high, the distribution was even, and the quantity of amino groups per polyester surface area was still very high. The surface properties of the produced polyester part were mainly characterised by polyethyleneimine. The grafting was able to resist several cycles of extraction in alkaline solutions. The stability was only limited by saponification of the polyester. The degree of surface modification was dependent on the molar mass of polyethyleneimine. This could be rationalised, because grafting only occurred with the one polyethyleneimine molecule that is in close vicinity to the polyester surface when both components come in contact. Fused deposition modelling was chosen as the model process with control over each processing step. However, any other moulding process may be applied, particularly injection moulding for mass production.

Surface functionalization of 3D printed poly-ε-caprolactone by ultrashort laser mirostructuring and ZnO nanolayer deposition

Due to its mechanical properties and good biocompatibility, polycaprolactone (PCL) is a promising material for bone tissue regeneration. However, a major limitation to its use remains the lack of inherent antimicrobial properties and its susceptibility to bacterial colonisation and biofilm formation. A potent strategy for overcoming such issues is surface functionalisation at micro and nano level, which can have a great impact on cell-surface interaction without affecting the integrity of the material. This study presents a novel methodology for surface modification of polymers combining ultrashort laser microstructuring and atomic layer deposition of ZnO. For this purpose, the surface of 3D printed PCL scaffolds was treated with a femtosecond laser (λ=800 nm; τ=75 fs) in order to develop parallel microchannels onto which ZnO nanolayers were further deposited. The presence of ZnO on the laser structured and unstructured scaffolds was detected by X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX). Both methods confirmed the successful layering as EDX further highlighted a trend that ZnO built up substantially more at the bottom of the microchannels rather than at the top of them. The obtained results would allow proceeding to the next step of the study – investigating the antimicrobial effect of the developed interfaces.

A review of polymer surface modification by cold plasmas toward bulk functionalization

AbstractPlasma surface modification of polymers is a well‐established method applied to increase the surface energy of these materials, where the capacity of cold plasmas to generate free radicals and functionalize the surface with polar groups is widely reported in the literature. This article provides a comprehensive literature review on plasma surface treatment, plasma‐induced grafting, and plasma polymerization, evaluating how these techniques can be applied to modify the bulk properties of polymers. A novel process of plasma‐induced polymer bulk functionalization in the melt state is introduced, where an atmospheric pressure plasma jet could be applied to a continuous reactive extrusion process, enhancing the production of graft copolymers for compatibilization of polymeric blends and fiber composites.

Can polymeric surface modification and sulfidation of nanoscale zerovalent iron (NZVI) improve arsenic-contaminated agricultural soil restoration via ex situ magnet-assisted soil washing?

Environmental context Arsenic (As) contamination in agricultural soil threatens safe agricultural production. Therefore, an ex situ magnet-assisted soil washing, using different types of nanoscale zerovalent iron was tested as a remediation option in soil restoration. Uncoated nanoparticles was the best tested option, with As removal at 45.5% and the nanoparticles were reusable up to four times. Rationale Arsenic (As) contamination in agricultural soil threatens safe food and medicinal herb production for millions of people. Methodology Therefore, ex situ magnet-assisted soil washing of metal-contaminated soil using bare nanoscale zerovalent iron (NZVI) is proposed as a novel remediation alternative. Conceptually, metal-contaminated soil is mixed with water and bare NZVI, and metals in the soil are transferred to the bare NZVI. The metal-sorbed NZVI is then retrieved from the soil slurry through magnetic separation, leaving behind treated soil. This study evaluated if advanced surface modification can improve ex situ soil restoration efficacy including polymeric coating and sulfidation of NZVI, proven beneficial in situ NZVI application. Sulfur and carboxymethylcellulose (CMC) at various S/Fe and CMC/NZVI ratios were used to modify NZVI via sulfidation and physisorption. Result Results revealed that sulfidised NZVI (S-NZVI) performed poorer (41.0%) than bare NZVI (45.5%) in As removal, even at the optimised S/Fe ratio of 0.31. This could be due to acid release via oxidative dissolution of FeS2 on the S-NZVI surface driven by O2. The incidental acid-dissolved NZVI sorption sites decreased As removal efficacy. Similarly, CMC-modified NZVI failed to improve As removal efficacy (11.0%) because it reduced NZVI reactivity and blocked As accessibility to NZVI sorptive sites. Discussion Nevertheless, S-NZVI and CMC-modified NZVI promoted non-phytoavailable As fractions in the treated soil. Overall, bare NZVI performed the best for As removal but moderately transformed As into more non-phytoavailable fractions. Bare NZVI can be reused for four cycles of soil washing. In every case, mobile As in treated soil was lower than the maximum contamination level.

Shear bond strength characteristics on surface treatment modalities of CAD-CAM resin polymers.

The purpose of this in vitro study was to analyze the shear bond strength of composite resin to a commercially available high-performance polymer material for fixed, screw-retained full arch restorations. A total of 135 computer-aided design and computer-aided manufacturing, high-performance polymer (HPP) blocks were cut and obtained from discs (Trilor 95, Harvest Dental, Brea, CA). The samples were 10mm × 10mm × 10mm. The specimen surfaces were grouped as untreated (Group A), 50 μm Al2O3 (Group B), 110 μm Al2O3 (Group C), Rocatec (3M, St. Paul, MN) activated with silica-modified alumina oxide treatment (Group D); and trimmed coarsely with a carbide bur (Group E). Group A samples were used as controls. After surface treatments, the specimens were gently cleansed with oil-free steam and alcohol wipes. Surface conditioning was performed on all physically treated samples. The manufacturer's recommendations were followed for bonding composite resin to the samples with light-cured Visio.link (Bredent, Chesterfield, UK). Cylinders were veneered with composite resins (diameter 5mm, height 4mm) and polymerized on the specimen surfaces through plastic tubes. Twenty-seven specimens were used for each testing group and aging tests were performed. The experimental samples were thermocycled. Shear bond strength and scanning electron microscopic tests were performed. Means and standard deviations were calculated. Statistical analysis was performed with post-hoc Tukey tests. Statistical analysis revealed that there was a significant difference between the groups (p<0.001). The highest shear bond strengths were achieved for the specimens bonded with Visio.link without physical surface treatments (270.47MPa). The lowest bond strengths were found for specimen surfaces abraded with 110 μm Al2O3 (117.03 Mpa) CONCLUSIONS: The results of this laboratory study indicated that the specimens used with Visio.link as provided by the manufacturer had the highest shear bond strengths between the composite resin and high-performance polymer test specimens. Modifications of the high-performance polymer surfaces with carbide burs did not change bonding strengths with the composite materials.

Editorial for a Special Issue on Plasma Technology and Its Applications

Plasma technology is commonly used in numerous fields, such as microelectronics, nanomaterial synthesis, nitrogen fixation, biomedicine, environmental protection, and polymer surface modification [...]

Surface modification of polymers by vacuum ultraviolet Illumination containing low wavelength below 160 nm and microfluidic applications of irradiated polycarbonate

Microfluidic devices are applied in various fields including medicine and drug discovery. Recently, plastics are used for the device due to low cost. One of the challenges is the bonding process. A bonding method that preserves the microstructure is required. Recently, room temperature bonding methods using vacuum ultraviolet (VUV) light have been reported, but the applicable materials are limited. Here, we propose a new method using VUV with a wavelength shorter than 160 nm. As a result of the surface analysis, it was confirmed that the substrate surface becomes hydrophilic upon VUV irradiation. As a result of the bonding test, it was confirmed that it was possible to bond polycarbonate (PC) to each other (maximum bonding force: 2.03 MPa), PC to glass (maximum bonding force: 10.72 MPa), and cyclic olefin polymer to glass (maximum bonding force: 3.51 MPa), which have not been reported so far. The results suggest that one of these bonding mechanisms is the addition of hydrophilicity by VUV irradiation. Based on the results, for the first time, a PC-made microfluidic device was successfully developed using the bonding method. This result greatly contributes to the development of the manufacturing process of plastic microfluidic devices.

Radical chemistry in polymer science: an overview and recent advances.

Radical chemistry is one of the most important methods used in modern polymer science and industry. Over the past century, new knowledge on radical chemistry has both promoted and been generated from the emergence of polymer synthesis and modification techniques. In this review, we discuss radical chemistry in polymer science from four interconnected aspects. We begin with radical polymerization, the most employed technique for industrial production of polymeric materials, and other polymer synthesis involving a radical process. Post-polymerization modification, including polymer crosslinking and polymer surface modification, is the key process that introduces functionality and practicality to polymeric materials. Radical depolymerization, an efficient approach to destroy polymers, finds applications in two distinct fields, semiconductor industry and environmental protection. Polymer chemistry has largely diverged from organic chemistry with the fine division of modern science but polymer chemists constantly acquire new inspirations from organic chemists. Dialogues on radical chemistry between the two communities will deepen the understanding of the two fields and benefit the humanity.

Facile Construction of Antimicrobial Surface via One-Step Co-Deposition of Peptide Polymer and Dopamine.

The infections associated with implantable medical devices can greatly affect the therapeutic effect and impose a heavy financial burden. Therefore, it is of great significance to develop antimicrobial biomaterials for the prevention and mitigation of healthcare-associated infections. Here, a facile construction of antimicrobial surface via one-step co-deposition of peptide polymer and dopamine is reported. The co-deposition of antimicrobial peptide polymer DLL60 BLG40 with dopamine (DA) on the surface of thermoplastic polyurethane (TPU) provides peptide polymer-modified TPU surface (TPU-DLL60 BLG40 ). The antimicrobial test shows that the TPU-DLL60 BLG40 surfaces of the sheet and the catheter both exhibit potent killing of 99.9% of methicillin-resistant Staphylococcus aureus (MRSA) and Escherichia coli (E. coli). In addition, the TPU-DLL60 BLG40 surface also exhibits excellent biocompatibility. This one-step antimicrobial modification method is fast and efficient, implies promising application in surface antimicrobial modification of implantable biomaterials and medical devices.

Discharge characteristics of an atmospheric pulsed microwave Ar/CF4 plasma jet

The atmospheric fluorocarbon plasma is widely used in surface modification of polymers. Recently, the pulsed microwave Ar/CF4 plasma jet is proved to be a promising atmospheric fluorocarbon plasma source with good performance. In this paper, the discharge characteristics of the pulsed microwave Ar/CF4 plasma jet are studied systematically. The discharge morphologies, ionization processes, optical emission spectra, and electron densities are obtained by a digital camera, an intensified charge coupled device, a fiber spectrometer, and a home-made microwave Rayleigh scattering device, respectively. The influences of the plasma operation parameters on the discharge characteristics are investigated, and the microwave input power and CF4 volume fraction are optimized. The results provide a basis for the generation and surface modification application of high-performance atmospheric fluorocarbon plasma.

From Basics to Frontiers: A Comprehensive Review of Plasma-Modified and Plasma-Synthesized Polymer Films.

This comprehensive review begins by tracing the historical development and progress of cold plasma technology as an innovative approach to polymer engineering. The study emphasizes the versatility of cold plasma derived from a variety of sources including low-pressure glow discharges (e.g., radiofrequency capacitively coupled plasmas) and atmospheric pressure plasmas (e.g., dielectric barrier devices, piezoelectric plasmas). It critically examines key operational parameters such as reduced electric field, pressure, discharge type, gas type and flow rate, substrate temperature, gap, and how these variables affect the properties of the synthesized or modified polymers. This review also discusses the application of cold plasma in polymer surface modification, underscoring how changes in surface properties (e.g., wettability, adhesion, biocompatibility) can be achieved by controlling various surface processes (etching, roughening, crosslinking, functionalization, crystallinity). A detailed examination of Plasma-Enhanced Chemical Vapor Deposition (PECVD) reveals its efficacy in producing thin polymeric films from an array of precursors. Yasuda's models, Rapid Step-Growth Polymerization (RSGP) and Competitive Ablation Polymerization (CAP), are explained as fundamental mechanisms underpinning plasma-assisted deposition and polymerization processes. Then, the wide array of applications of cold plasma technology is explored, from the biomedical field, where it is used in creating smart drug delivery systems and biodegradable polymer implants, to its role in enhancing the performance of membrane-based filtration systems crucial for water purification, gas separation, and energy production. It investigates the potential for improving the properties of bioplastics and the exciting prospects for developing self-healing materials using this technology.

Surface modification of polymers by ion irradiation: Reactivity principle and application

Modifying polymers through ion irradiation is an advantageous method for controlling polymer with desirable properties. The surface modification mechanism and application of polymers by ion irradiation are under exploration. This review systematically analyzes the recent progress on the surface modification of common polymers by ion irradiation. The fundamentals of irradiation principle and chemical interaction, the irradiation effect of microstructure, macroproperties, and related characterization methods are introduced for the innovated applications. The effect of ion beam conditions (heavy or light ions, high or low energy/fluences) on different polymers is systematically analyzed for the different irradiation effect to achieve surface modification, in which the coupling mechanism between nuclear and electronic stopping power is provided. To meet the requirement of various application, the relationship between micro representation and macro performance is thoroughly discussed and established combined with the concerns regarding ion irradiation induced regulation mechanism. For the practical/potential application prospects, the frontier research on membrane separation, electrical, and biomedical applications are discussed. This review offers valuable insights into the modified microstructures versus the necessary surface properties of polymer by ion irradiation.

ZIF-8 induced hydroxyapatite-like crystals enabled superior osteogenic ability of MEW printing PCL scaffolds

ZIF-8 may experience ion-responsive degradation in ionic solutions, which will change its initial architecture and restrict its direct biological use. Herein, we report an abnormal phenomenon in which ZIF-8 induces large hydroxyapatite-like crystals when soaked directly in simulated body fluid. These crystals grew rapidly continuously for two weeks, with the volume increasing by over 10 folds. According to Zn2+ release and novel XRD diffraction peak presence, ZIF-8 particles can probably show gradual collapse and became congregate through re-nucleation and competitive coordination. The phenomenon could be found on ZIF-8/PCL composite surface and printed ZIF-8/PCL scaffold surface. ZIF-8 enhanced PCL roughness through changing the surface topography, while obviously improving the in-vivo and in-vitro osteoinductivity and biocompatibility. The pro-biomineralization property can make ZIF-8 also applicable in polylactic acid-based biomaterials. In summary, this study demonstrates that ZIF-8 may play the role of a bioactive additive enabling the surface modification of synthetic polymers, indicating that it can be applied in in-situ bone regeneration.