Previously, we had developed a new negative-type phenolic polymer-based photosensitive resin composition ROD-100, patternable by photolithography and having low coefficient of thermal expansion (CTE), low residual stress, and high heat resistance after thermally treated at 260 ℃. We had confirmed an interesting phenomenon in which the phenolic resin itself, without crosslinking agents and photochemical acid generators, had showed further lower CTE and residual stress than ROD-100. In the current study, to study the applicability of the phenolic resin as a semiconductor packaging insulating material, we utilized laser ablation to examine the pattern formation on thin films of the phenolic resin as well as investigated the effects of the heat-treatment temperature and the addition of crosslinking agents on the residual stress and the chemical resistance. The combination of laser ablation and desmear treatment resulted in successful pattern formation. This material is a good candidate as an insulating material for fan-out wafer-level packaging (FO-WLP).

The photo-alignment properties of 4,4-(hexafluoroisopropylidene) diphthalic anhydride (6FDA)-based polyimides with sterically hindered diamine component were systematically evaluated, such as 6FDA-3,3'-dimethylbenidine, 6FDA-2,7-diaminofluorene, 6FDA- 2,3,5,6-tetramethyl-1,4-phenylene diamine, 6FDA-2,5-diamino-1,4-phenylenediamine, 6FDA-1,4-phenylenediamine, and 6FDA-1,3-phenylenediamine. To evaluate sterically hindered diamine components, the diamine components with varying number of benzyl ring and methyl group were used. The polyimides containing the diamine components with methyl group were well planarity and forming charge transfer complex efficiently. The polyimides showing photo reaction property by linearly polarized ultra violet light induced photo alignment properties, however, the linear structured polyimide induced photo alignment property even it showed poor photo reaction property.

This study aimed to compare the biocompatibility of two different self-adhering flowable resin composites (SAFCs). 54 polyethylene tubes filled with two different SAFCs [Group V: Vertise Flow (VF), Group F: Fusio Liquid Dentin (FLD), or Group C: empty (Control)] were implanted into the subcutaneous tissue of 18 rats. After 7, 30, and 90 days of implantation, the rats were euthanatized (n=6). The implanted materials were removed with the surrounding tissue for histologic evaluation. The subjects were evaluated in terms of inflammation, fibrous capsule thickness, necrosis, macrophage, and giant cell presence. When the SAFC groups and Group C were compared on days 7, 30, and 90, inflammation, fibrous capsule thickness, and macrophage on the 7th day were statistically significant (p<0.05). Statistically, the giant cell and macrophage criteria were statistically significant on the 7th, 30th, and 90th days in all groups (p<0.05). When the groups were evaluated on different days among themselves, significant differences were observed in terms of local tissue response (p<0.05), while necrosis was found to be statistically insignificant (p>0.05). Biocompatibility was found similar for the SAFCs. These materials used in the study have shown good biocompatibility in rats, and SAFCs can be considered suitable for all restorative treatments.

Synthesis of silver nanoparticles (AgNPs) by use of well-tested reducing and capping agents has been studied widely to produce desired product qualities for many usages. However, the size, morphology, and stability of the colloidal AgNPs remain subject to intensive works. Here, we report on the stable EDTA capped AgNPs prepared by reducing Ag⁺ ions using ascorbic acid (AA) stabilized with ethylenediaminetetraacetate (EDTA) at mild conditions. The pH medium, the reducing and stabilizing agent concentrations, temperature, and reaction time were evaluated to give stable and monodispersed colloidal nanoparticles. The synthesis of colloidal AgNPs was successful at medium pH of 11 and a temperature of 30 ℃. The peak of colloid localized surface plasmon resonance (LSPR) absorbance was observed at 396–398 nm, having a size distribution of about 17.9–23.8 nm, spherical shape, monodisperse, and zeta potential of –25.8 mV. The produced nanomaterials have good stability up to 24 weeks of storage time. The fabricated AgNPs show long-term stability, which is very promising for many potential applications.

With the continuous growth of industrialization, residual dyes degradation has been a hotspot in present research. Herein, the immobilization of ZnO into polychlorotrifluoroethylene-co-acrylate (PCTFE-co-acrylate) matrix render hybrid film with good hydrophilicity and ageing resistance. We studied the effects of different ZnO/PCTFE-co-acrylate ratio on photocatalytic behavior under ultraviolet illumination. The best degradation ability of methylene blue (MB) was obtained for PZ-1 owe to Zn²⁺ and defect levels, which achieved up to 96.3% at 120 min later. Meanwhile, concerned kinetics property was adequately explored, which match well with pseudo-first order reaction. Such a simple, green and convenient approach provides a high-performance hybrid film for dyes wastewater purification.

Ultraviolet curing (UV) water-based inks have the advantages of low viscosity, high gloss, and a wide range of applications. But there are defects such as slow curing speed and low degree of crosslinking. In this paper, the copolymer P(MMA-r-AA) was prepared by traditional free radical polymerization using methyl methacrylate (MMA) and acrylic acid (AA) as monomers, and the copolymer P(MMA-r-AA) was modified by hydroxyethyl methacrylate (HEMA) to obtain acrylic prepolymer P(MMA-r-AA)-g-HEMA contained double bonds. The reaction of triethylenetetramine and glycidyl methacrylate (GMA) yielded a multifunctional reactive diluent triethylenetetramine hexamethacrylic acid glycidyl amide (TGMA). Secondly, acrylic prepolymer P(MMA-r-AA)-g-HEMA, multifunctional reactive diluent TGMA, photoinitiator and yellow pigment were used to prepare UV-curing ink. The influence of the type and mass fraction of photoinitiator, the relative molecular weight and mass fraction of P(MMA-r-AA)-g-HEMA, and the number of functional groups and mass fraction of TGMA on the photocuring speed of UV ink and the abrasion resistance of ink film were discussed. When the mass fraction of the photoinitiator TPO was 1%, the number-average relative molecular mass of the prepolymer was 1.99×10⁵ g/mol and the mass fraction was 40%, and the number of functional groups of the reactive diluent was 6 and the mass fraction was 60%, the light curing of water-based UV ink was completed in 0.1s, and the mass loss after 50 times abrasion was about 0.2%. And this kind of UV ink can be used to prepare UV conductive ink and UV magnetic ink.

Carrageenan-based hydrogel, as a kind of natural polymer soft material with a three-dimensional network structure, has good biocompatibility, biodegradability and biosafety, and has high water content, structure and performance. The matrix is similar and has received extensive attention from researchers. This article outlines the structure and properties of carrageenan-based hydrogels, and classifies carrageenan-based hydrogels according to their functionality, focusing on self-healing, antibacterial, stimulus-responsive, and conductive carrageenan-based hydrogels. The characteristics and properties of glue and its application progress in drug delivery, wound healing, tissue engineering, and biological intelligent sensing. Finally, the problems and challenges faced by carrageenan-based hydrogels are discussed, and the future of carrageenan-based hydrogels are prospected. Possible development trend.

High refractive index, colorless and transparent thermoplastic nanocomposites were successfully prepared from polythiocyanurate and ZrO₂ nanoparticles using triazine-based surface modifying agent (TSMA). TSMA was designed to consist of triazine units, sulfur atoms and p-xylylene moieties and synthesized to control molecular weights of 3,000-5,000. The nanocomposites with sufficient compression moldability showed homogeneous dispersion of ZrO₂ nanoparticles. The films of nanocomposites fabricated by compression molding exhibited high refractive index up to 1.8 and high total light transmittance of 84% and haze value of less than 2.0% in visible region. The high refractive index nanocomposites are promising candidates as advanced materials for optical applications that require high moldability such as aspherical camera lenses for smartphones.

As an emerging developing technique for next-generation lithography, from self-assembly to directed self-assembly of block copolymer has attracted numerous attentions and has been a potential alternative to supplement the intrinsic limitations of conventional photolithography. In this work, a novel high-χ block copolymer Polystyrene-b-Polytrimethylene Carbonate (PS-b-PTMC) material has been successfully synthesized. It can be directly coated on Si substrates to form periodic micro-phase separation structures by annealing processes without the use of neutral layer or additional top coat. A unique self-assembly surface defect phenomenon called as black and white spots shows two different colors in SEM view. An in-depth study on the phenomenon has been carried out, including experimental characterization analysis, mechanism exploration, process optimization, etc., to find out the internal mechanism leading to the formation of such defects. It is necessary to balance both polymer/substrate and polymer/the free surface interfaces, which could induce the perpendicular orientation of microdomains. On this basis, the mechanism self-assembly defects has been proposed, and then an effective process scheme to remove the defects without affecting the formation of periodic vertical micro-phase separation patterns has also been provided, which showed a great potential of novel block copolymer under the condition of neutral layer free. We also realized the elimination of black and white spots by optimizing the process condition of BCP self-assembly and directed self-assembly (DSA). Valuable information and insights are provided for nanowire patterning in state-of-the-art semiconductor devices.

Most studies on (super)hydrophobic/oleophobic materials/surfaces have particularly focused on the effects of surface textures and surface modifications with long-chain perfluorinated compounds (LCPFCs) to achieve maximum static contact angle (CA, θ_S) and minimize the contact area between the probe liquid and the solid surface. However, it has recently been recognized that such θ_S value alone does not faithfully reflect the actual surface wetting properties. Hence, the importance of dynamic wettability evaluation, such as dynamic (advancing (θ_A) and receding (θ_R)) CAs, CA hysteresis (θ_A−θ_R (Δθ) or cosθ_R−cosθ_A (Δθ_cos)), and substrate tilt/sliding angle (α), has recently been recognized as a better way to estimate the actual surface wettability of the target materials. For example, if the apparent CA is small, as long as the CA hysteresis is small enough or negligible, excellent liquid sliding properties can be realized not only with aqueous liquids but also with organic liquids having low surface tensions. To reduce CA hysteresis, the use of “liquid-like” surfaces, on which surface-tethered functional groups can rotate freely and provide a surface with liquid-like nature, is promising because such surfaces can be prepared without relying on either fragile surface micro/nanostructures or subsequent perfluorination with harmful LCPFCs, in addition to excellent liquid sliding behavior. In this mini-review, we focused on the recent progress in research on liquid-like surfaces with low CA hysteresis demonstrating excellent sliding of various probe liquids. We highlighted some of the representative studies and concluded with a brief discussion of future directions in this promising research field.

Transfer printing is a powerful technique for the quick and cost-effective creation of micro-structured patterns from various electronic materials. However, the production of the required stamps is often costly and time-consuming. In this study, we demonstrate how such a stamp can be custom designed and quickly made from a polyurethane-based resin by three-dimensional vat photopolymerization. A stamp featuring an array of 204 by 512 µm sized pixels was reproduced with a high dimensional accuracy of ±0.25% and successfully applied in transfer printing of a quantum dot (QD) material with electroluminescent properties. Due to the working principle of the printer used, both the stamp and the print image obtained had a characteristic yet homogeneous raster pattern. The insights gained will be useful in the additive manufacturing of tools for use in printing electronic devices.

A reworkable resin, which is degradable after use, was developed for application as a dental resin. A dimethacrylate monomer containing a ketal linkage in the molecule was used as a reworkable monomer. The reworkable monomer was successfully cured by blue light irradiation (470-nm light) using the camphorquinone/amine photoinitiating system. The cured reworkable resins were degraded in the presence of a UV- and violet-light sensitive photoacid generator by prolonged irradiation at room temperature. The degradation was due to the acid-catalyzed decomposition of the ketal linkages in the cured reworkable monomers. The preliminary result suggested the possibility of application of the reworkable monomer as dental resins.

We have developed a stochastic simulation of the pattern formation process for positive type resists in electron beam lithography that introduces an improved model of the development process. In the model, the resist dissolved in order from the surface to the substrate, and the dissolution probability of the resist molecules depended on the molecular weight. The development characteristics obtained by the simulation was evaluated for Poly(methyl methacrylate) resist. The improved simulation made it possible to reproduce the time-dependent development process of the resist. The dependences of resist molecular weight, development time, and exposure dose on the development obtained by simulation was quantitatively evaluated by comparing with the experimental results.