Macroscopic Room-Temperature Magnetoelectricity in Piezoelectric (Core)-Ferrimagnetic (Shell) Nanocomposites.

The magnetoelectric (ME) effect, which involves the interaction of magnetic and electric fields within a material, has a significant potential for various applications. Our study addresses the limitations of conventional magnetostriction-based ME materials by demonstrating an alternative approach that achieves substantial ME effects in core-shell-type nanocomposites at room temperature. By synthesizing ferrimagnetic FeO nanoparticles onto piezoelectric poly(vinylidene fluoride) (PVDF) particles, we identified a distinct ME mechanism.

High Glass Transition Temperature Fluorinated Polymers Based on Transfer Learning with Small Experimental Data.

Machine learning can be used to predict the properties of polymers and explore vast chemical spaces. However, the limited number of available experimental datasets hinders the enhancement of the predictive performance of a model. This study proposes a machine learning approach that leverages transfer learning and ensemble modeling to efficiently predict the glass transition temperature (T) of fluorinated polymers and guide the design of high T copolymers.

A strategy for preparing controllable, superhydrophobic, strongly sticky surfaces using SiO@PVDF raspberry core-shell particles.

In nature, wetting by water droplets on superhydrophobic materials is governed by the Cassie-Baxter or Wenzel models. Moreover, sticky properties, derived from these types of wettings, are required for a wide range of applications involving superhydrophobic materials. As a facile new strategy, a method employing a gaseous fluorine precursor to fabricate core-shell particles, comprising perfectly shaped fluorine shells with adjustable adhesive strength, is described in this paper.

Flexible, Elastic, and Superhydrophobic/Superoleophilic Adhesive for Reusable and Durable Water/Oil Separation Coating.

This study investigates a highly flexible/stretchable and mechanically durable superhydrophobic/superoleophilic coating for efficient oil/water separation and oil absorption. The coating is applied via a simple immersion process using a mixed solution of a biocompatible adhesive (ethyl cyanoacrylate, ECA), a highly stretchable polymer (polycaprolactone, PCL), and superhydrophobic/superoleophilic nanoparticles (fluorine-coated silica nanoparticles, F-SiO NPs) in a solvent, followed by solvent evaporation and ECA polymerization. Polymerized ECA (poly-ECA) in the coating material strongly adheres the F-SiO NPs to the substrate surface, while PCL bestows the rigid poly-ECA with high flexibility.

Blood Oxygenation Using Fluoropolymer-Based Artificial Lung Membranes.

Artificial lung (AL) membranes are used for blood oxygenation for patients undergoing open-heart surgery or acute lung failures. Current AL technology employs polypropylene and polymethylpentene membranes. Although effective, these membranes suffer from low biocompatibility, leading to undesired blood coagulation and hemolysis over a long term.

Perfluoropolyether-benzophenone as a highly durable, broadband anti-reflection, and anti-contamination coating.

Anti-reflection and anti-contamination coatings prepared from fluorinated polymers have widespread and important applications, ranging from protective films for corrosion resistance to high-tech microelectronics and medical devices due to their transparency, low refractive index, stain resistance, and antifouling properties. However, the application of existing coatings is hindered by low surface adhesion to the target substrate and weakness when exposed to mechanical stress or damage, resulting in significant limitations to their practical applications. Herein, we incorporate perfluoropolyether (PFPE) with benzophenone (BP) to develop an efficient coating material (PFPE-BP) possessing broadband anti-reflectivity, anti-contamination properties, excellent abrasion resistance, and stability under elevated temperatures and relative humidity.

Preparation and electroactive phase adjustment of Ag-doped poly(vinylidene fluoride) (PVDF) films.

The crystallinities of Ag-doped poly(vinylidene fluoride) (PVDF) films were modified by removing Ag using a novel washing process, which allowed control of the ratio of γ- and β-phases. The polarity of the composite film without Ag removal through the washing process reached 98%, and the β-phase content in the total electroactive phase was increased to 61%, according to Fourier-transform infrared spectroscopy. When Ag were removed through a process involving several cycles of washing, filtering, drying, and re-dissolving, the highest ratio of the γ-phase was increased to 67%, 28% higher than that before washing.

Fluorinated Titania Nanoparticle-Induced Piezoelectric Phase Transition of Poly(vinylidene fluoride).

We prepared F-coated rutile titanium dioxide nanoparticles (r-TiO NPs) via simple thermal annealing of titania NPs in poly(vinylidene fluoride) (PVDF) and demonstrated that the F-coated r-TiO NP-doped composite film could efficiently induce piezoelectric phase transition of non-electroactive PVDF due to highly electronegative F bonds on the surface of these NPs. In the case of a 2.0 wt % composite film, 99.

Controllable Surface and Optical Properties of Methacrylic Copolymer Films Using Various Monomer Combinations.

Various fluorinated methacrylic copolymers (PFPMA- X) were prepared from 2,2,3,3,3-pentafluoropropyl methacrylate (PFPMA), methyl methacrylate (MMA), and three other nonfluorinated monomers. The surface and the optical properties of these copolymers were controlled by changing the ratio of PFPMA to MMA while keeping the sum of the concentration of the two monomers fixed at 60 wt %. The parameter X represents the nominal concentration of PFPMA in various feed ratios of all five monomers.

Ultra-hydrophobic sticky polymer surfaces formed by water-induced surface deformation.

Surface properties of poly(oxyethylene)s with alkyl thioether side chains (CH-nTE; n=carbon atoms in the side chain) were investigated. CH-nTEs having shorter side chains (n=6, 8, 10) did not have ordered structures, while those with longer chains (n=12, 14) showed well-ordered, lamellar structures with side chain crystalline domains. Accordingly, CH-12TE and CH-14TE film surfaces were much more enriched with hydrophobic alkyl side chains than CH-8TE and CH-10TE surfaces.

Tuning Surface Properties of Poly(methyl methacrylate) Film Using Poly(perfluoromethyl methacrylate)s with Short Perfluorinated Side Chains.

To control the surface properties of a commonly used polymer, poly(methyl methacrylate) (PMMA), poly(perfluoromethyl methacrylate)s (PFMMAs) with short perfluorinated side groups (i.e., -CF3, -CF2CF3, -(CF3)2, -CF2CF2CF3) were used as blend components because of their good solubility in organic solvents, low surface energies, and high optical transmittance.

Improved field-effect transistor performance of a benzotrithiophene polymer through ketal cleavage in the solid state.

A benzotrithiophene polymer with a new thermally cleavable ketal substituent is reported. It is shown how this functional group can be used to facilitate solvent processing and, subsequently, how it can be removed by a thermal annealing process to generate a structurally ordered and crystalline thin film with significantly improved field-effect transistor properties.

Collapse of homeotropic liquid-crystal alignment by increased molecular packing on comb-like polymer surfaces.

We report an unusual alignment behavior of liquid crystals (LCs) on well-ordered comb-like poly(oxyethylene) surfaces. The homeotropic LC alignments that are observed on as-coated surfaces of the polymers are transformed to the random planar type after annealing treatment, even though the molecular structure of the polymer surface becomes more ordered and the surface energy decreases. Studies of the surface properties, such as molecular structure, morphology, and wettability, reveal that such an unexpected alteration of the LC alignment originates from the density of the alkyl side chains being enhanced by localized packing.

Surface characterization and liquid crystal alignment behavior of comb-like poly(oxyethylene)/poly(3-hexylthiophene) blend films.

The blend surfaces of poly[oxy(n-decylsulfonylmethyl)ethylene] (CH(3)-10SE) and poly (3-hexylthiophene) (P3HT) with different weight ratios were prepared by spin coating the polymer solution mixtures. In this study, their surface properties such as surface morphology, chemical composition, molecular structure, and wettability were systematically studied and correlated with liquid crystal (LC) alignment behaviors on the blend films. Therefore, we found that CH(3)-10SE part with a well-ordered side chain structure predominantly affects the both of wettability and LC alignment behavior of the blend films while there was no clear association between the wettability and the LC alignment behavior.

Bacterial adhesion-resistant poly(2-hydroxyethyl methacrylate) derivative for mammalian cell cultures.

In an attempting to find new biomaterials for mammalian cell culture, PHEMA derivatives with ester side groups are synthesized by one-step polymer-analogous reaction. These polymers show excellent antifouling properties against S. epidermidis and P.

Silver-perfluorodecanethiolate complexes having superhydrophobic, antifouling, antibacterial properties.

Silver-perfluorodecanethiolate complexes having superhydrophobic, antifouling, antibacterial properties were prepared by a reaction of silver nitrate with perfluorodecanethiol. When the silver nitrate to perfluorodecanethiol molar ratio was 1/2, silver-perfluorodecanethiolate complexes having hierarchical micro-/nano-sized wire shapes were obtained, and they showed superhydrophobic and antifouling properties. After UV irradiation, silver nanoparticles were generated on the wires and exhibited antibacterial properties.

Surface properties and liquid crystal alignment behavior of poly(2-hydroxyethyl methacrylate) derivatives with alkyl ester side chains.

Poly(2-hydroxyethyl methacrylate) derivatives with amphiphilic side chains composed of polar ester and non-polar alkyl groups (PHEMA#C, #=9, 11, 13, 15, and 17), where # is the number of carbon atoms in the alkyl side groups, were synthesized. In this paper, the influence of ester and alkyl groups on the molecular structure and wettability of the polymers were studied through varying # in the alkyl side groups. PHEMA#Cs with relatively longer alkyl side groups (#≥15) show bilayer lamellar structures with well aligned side chains giving rise to the very low surface energies, calculated from advancing contact angles, in the range of 22.

Effect of n-alkyl and sulfonyl groups on the wetting properties of comblike poly(oxyethylene)s and stick-slip behavior.

The influence of side chain length and sulfonyl moiety on the molecular structures and wettability behavior of poly(oxyethylene)s with alkyl sulfonyl side chains (CH(3)-nSE, n = 1, 2, 3, 4, 5, 6, 8, 10), where n is the number of the carbon atom in the n-alkyl side group, was investigated. CH(3)-nSEs having shorter side chains (n < 5) do not have ordered structures, and their surfaces were found to be more polar than those of CH(3)-nSEs having longer side chains (n ≥ 5). The CH(3)-nSEs having longer side chains show double-layered lamellar structures (n ≥ 5) with well-aligned side chains and low surface energies in the range 21.

Wettability of the morphologically and compositionally varied surfaces prepared from blends of well ordered comb-like polymer and polystyrene.

Phase-separated surfaces of blends of polystyrene (PS) and well ordered comb-like polymer, poly[(oxy(decylsulfonylmethyl)ethylene)] (CH(3)-10SE), were prepared by spin casting polymer mixtures. Various surface morphologies, such as holes, islands, connected islands and pillars, were prepared by changing the blend compositions. Due to the influence of the CH(3)-10SE domain with a well ordered molecular conformation, a very low energy surface (≈22mN/m) was created, which is close to the value of the pure polymer (≈20mN/m), even when the blends contained only 20wt.

Inhibition of bacterial adhesion on well ordered comb-like polymer surfaces.

The surfaces of comb-like poly(oxyethylene) derivatives with n-alkylsulfonyl side groups were more effective at reducing Pseudomonas aeruginosa adhesion than the surfaces of common materials such as polystyrene, poly(methyl methacrylate), poly(dimethylsiloxane), fluorinated polyacrylate, and glass. When the comb-like poly(oxyethylene) was mixed with polystyrene and poly(methyl methacrylate), the topology and roughness of the surfaces varied according to the mixture compositions. However the surface energies of the mixtures were close to that of the comb-like poly(oxyethylene) in the range of 21-23 mN/m and bacterial adhesion resistances of the mixture surfaces were also comparable to that of the pure comb-like poly(oxyethylene) surface.

Comb-like polymer blends of poly(oxyethylene)s with CH3-terminated and CF3-terminated alkylsulfonylmethyl side chains: effect of terminal CF3 moiety on the surface properties of the blends.

The surface properties of comb-like polymer blends of poly(oxyethylene)s having CH(3)-terminated and CF(3)-terminated alkylsulfonylmethyl side chains were studied. These side chains were found to be well oriented on the surface of the blends, while being phase separated, forming various surface morphologies composed of holes, islands, or connected islands, because of their immiscibility resulting from their different polarities. The domain size of each polymer on the blend surface was found to be almost linearly proportional to the bulk compositions of the mixture, and the CF(3)-terminated alkylsulfonylmethyl side chain domains were found to be located in the lower region of the surface.