Low-temperature, ultra-fast, and recyclable self-healing nanocomposites reinforced with non-solvent silylated modified cellulose nanocrystals.

Developing polymeric materials with remarkable mechanical properties and fast self-healing performance even at low temperatures is challenging. Herein, the polymeric nanocomposites containing silane-treated cellulose nanocrystals (SCNC) with ultrafast self-healing and exceptional mechanical characteristics were developed even at low temperatures. First, CNC is modified with a cyclic silane coupling agent using an eco-friendly chemical vapor deposition method.

Polyether-based waterborne synergists: effect of polymer topologies on pigment dispersion.

Control of polymer topologies is essential to determine their unique physical properties and potential applications. The polymer topologies can have a critical effect on pigment dispersion owing to their unique architectures; however, studies using polymer topologies on pigment dispersion in aqueous systems are scarce. Thus, this study proposes various topologies of polyether-based waterborne synergists, such as linear, hyperbranched, and branched cyclic structures.

NIR-Triggered High-Efficiency Self-Healable Protective Optical Coating for Vision Systems.

Recently, self-healing materials have evolved to recover specific functions such as electronic, magnetic, acoustic, structural or hierarchical, and biological properties. In particular, the development of self-healing protection coatings that can be applied to lens components in vision systems such as augmented reality glasses, actuators, and image and time-of-flight sensors has received intensive attention from the industry. In the present study, we designed polythiourethane dynamic networks containing a photothermal -butyl-substituted diimmonium borate dye to demonstrate their potential applications in self-healing protection coatings for the optical components of vision systems.

Cellulose nanocrystal nanocomposites capable of low-temperature and fast self-healing performance.

The development of low-temperature self-healing polymers is crucial because high-temperature or softening conditions for rapid self-healing inevitably reduce their mechanical strength. Herein, we first report cellulose nanocrystal (CNC)/polymer nanocomposites with a rapid low-temperature self-healing performance. The nanocomposite was prepared by simple blending of grafted CNC and matrix prepolymer made from the monomers having metal-ligand coordination and lower critical solution temperature functionalities along with the presence of hexamethylene diisocyanate and dibutyltin dilaurate.

Simultaneous removal of heavy metal ions using carbon dots-doped hydrogel particles.

Heavy metal ions (HMI) have attracted worldwide concern due to their serious environmental pollution which led to the risk of health conditions. From Red Malus floribunda fruits, nitrogen-doped carbon dots (N-CDs) were prepared, followed by hybrid-spherical shaped hydrogel particles (CGCDs) were prepared. The prepared CGCDs were utilized as adsorbents for HMI-(Hg(II), Cd(II), Pb(II), and Cr(III)) from water.

Recent Studies on Dispersion of Graphene-Polymer Composites.

Graphene is an excellent 2D material that has extraordinary properties such as high surface area, electron mobility, conductivity, and high light transmission. Polymer composites are used in many applications in place of polymers. In recent years, the development of stable graphene dispersions with high graphene concentrations has attracted great attention due to their applications in energy, bio-fields, and so forth.

Influence of Material Properties on the Damage-Reporting and Self-Healing Performance of a Mechanically Active Dynamic Network Polymer in Coating Applications.

We conducted a detailed investigation of the influence of the material properties of dynamic polymer network coatings on their self-healing and damage-reporting performance. A series of reversible polyacrylate urethane networks containing the damage-reporting diarylbibenzofuranone unit were synthesized, and their material properties (e.g.

Noncovalent Functionalized Graphene Nanocarriers from Graphite for Treating Thyroid Cancer Cells.

Here, biocompatible graphene (G) nanocarriers decorated with iron oxide nanoparticles (IONPs) were prepared using 2-(methacryloyloxy)ethyl phosphorylcholine (MPC) and poly(ethylene glycol) monomethacrylate (PEGMA). For this, we report the use of graphite directly instead of graphene oxide or reduced graphene oxide. Graphene nanocarrier ( GIOPMPC) was prepared in one-pot by copolymerization of MPC and PEGMA monomers in the presence of IONPs and G.

Environmentally Adaptable and Temperature-Selective Self-Healing Polymers.

Development of polymeric materials capable of self-healing at low temperatures is an important issue since their mechanical strength and self-healing performance are often in conflict with each other. Herein, random copolymers with self-healing capability in a wide temperature range prepared from 2-(dimethylamino)ethyl methacrylate (DMAEMA), glyceryl monomethacrylate (GlyMA), and butyl methacrylate monomers via free-radical polymerization and subsequent cross-linking with hexamethylene diisocyanate are reported. Wound closure is facilitated by swelling below the lower critical solution temperature or by heating above the glass transition temperature (T ) of the polymer.

Interaction of Zwitterionic and Ionic Monomers with Graphene Surfaces.

Measurement of the interaction force between two materials provides important information on various properties, such as adsorption, binding, or compatibility for coatings, adhesion, and composites. The interaction forces of zwitterionic and ionic monomers with graphite platelets (G) and reduced graphene oxide (rGO) surfaces were systematically investigated by atomic force microscopy (AFM) in air and water. The monomers examined were 2-(methacryloyloxy)ethyl 2-(trimethylammonio)ethyl phosphate (MPC), [2-(methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBE), [2-(acryloyloxy)ethyl]trimethylammonium chloride (ATC), and 2-methyl-2-propene-1-sulfonic acid sodium (MSS).

A study on amphiphilic fluorinated block copolymer in graphite exfoliation using supercritical CO for stable graphene dispersion.

In this study, poly(2,2,2-trifluoroethyl methacrylate)-block-poly(4-vinylpyridine) (PTFEMA-b-PVP) was synthesized by stepwise reversible addition-fragmentation chain transfer (RAFT) polymerization for the preparation of graphene by the exfoliation of graphite nanoplatelets (GPs) in supercritical CO (SCCO). Two different block copolymers (low and high molecular weights) were prepared with the same block ratio and used at different concentrations in the SCCO process. The amount of PTFEMA-b-PVP adsorbed on the GPs and the electrical conductivity of the SCCO-treated GP samples were evaluated using thermogravimetric analysis (TGA) and four-point probe method, respectively.

High-concentration graphene dispersion stabilized by block copolymers in ethanol.

This article describes a comprehensive study for the preparation of graphene dispersions by liquid-phase exfoliation using amphiphilic diblock copolymers; poly(ethylene oxide)-block-poly(styrene) (PEO-b-PS), poly(ethylene oxide)-block-poly(4-vinylpyridine) (PEO-b-PVP), and poly(ethylene oxide)-block-poly(pyrenemethyl methacrylate) (PEO-b-PPy) with similar block lengths. Block copolymers were prepared from PEO using the Steglich coupling reaction followed by reversible addition-fragmentation chain transfer (RAFT) polymerization. Graphite platelets (G) and reduced graphene oxide (rGO) were used as graphene sources.

Stimuli-triggered Formation of Polymersomes from W/O/W Multiple Double Emulsion Droplets Containing Poly(styrene)-block-poly(N-isopropylacrylamide-co-spironaphthoxazine methacryloyl).

We report stimuli-triggered fabrication of polymersomes from water-in-oil-in-water (W/O/W) multiple double emulsion droplets and the dual-stimuli (temperature and UV) responsive behavior of corresponding polymersomes. The polymersome comprises Tween20, cholesterol, and poly(styrene)-block-poly(N-isopropylacrylamide-co-spironaphthoxazine methacryloyl), i.e.

Amphiphilic Fluorinated Block Copolymer Synthesized by RAFT Polymerization for Graphene Dispersions.

Despite the superior properties of graphene, the strong π⁻π interactions among pristine graphenes yielding massive aggregation impede industrial applications. For non-covalent functionalization of highly-ordered pyrolytic graphite (HOPG), poly(2,2,2-trifluoroethyl methacrylate)--poly(4-vinyl pyridine) (PTFEMA--PVP) block copolymers were prepared by reversible addition-fragmentation chain transfer (RAFT) polymerization and used as polymeric dispersants in liquid phase exfoliation assisted by ultrasonication. The HOPG graphene concentrations were found to be 0.

Near-Room Temperature Synthesis of Core/Shell-Structured Quantum Dots.

Core/shell-structured quantum dots (QDs) are considered as important active materials for optoelectronic devices. There have been a lot of synthesis procedures developed so far. Real epitaxial growth of shell layer, however, has not been reported yet.

PVP-b-PEO block copolymers for stable aqueous and ethanolic graphene dispersions.

The ability to disperse pristine (unfunctionalized) graphene is important for various applications, coating, nanocomposites, and energy related systems. Herein we report that amphiphilic copolymers of poly(4-vinyl pyridine)-block-poly(ethylene oxide) (PVP-b-PEO) are able to disperse graphene with high concentrations about 2.6mg/mL via sonication and centrifugation.

Facile Synthesis of Monodispersed Cubic and Spherical Calcite Nanoparticles in the Presence of Cetyltrimethylammonium Bromide.

We report the synthesis of monodisperse calcium carbonate (CaCO3) (nano)particles having either a cubic or spherical structure by reacting calcium nitrate with either sodium carbonate or citric acid, respectively, in the presence of cetyltrimethylammonium bromide (CTAB) via the sonication method. For comparison, CaCO3 (nano)particles were synthesized by the same method in the absence of CTAB and also via the standard hydrothermal method using CTAB. The synthesized CaCO3 (nano)particles were analyzed by various physico-chemical characterization techniques such as X-ray diffraction (XRD), Fourier transform infra-red spectroscopy, thermogravimetric analysis, and scanning electron microscopy with energy-dispersive spectrometer.

Fluorescent Molecular Rotor-in-Paraffin Waxes for Thermometry and Biometric Identification.

Novel thermoresponsive sensor systems consisting of a molecular rotor (MR) and paraffin wax (PW) were developed for various thermometric and biometric identification applications. Polydiphenylacetylenes (PDPAs) coupled with long alkyl chains were used as MRs, and PWs of hydrocarbons having 16-20 carbons were utilized as phase-change materials. The PDPAs were successfully dissolved in the molten PWs and did not act as an impurity that prevents phase transition of the PWs.

Photoresponsive phase separation of a poly(NIPAAm-co-SPO-co-fluorophore) random copolymer in W/O droplet.

The photoresponsive phase separation of a poly(N-isopropylacrylamide-co-spironaphthoxazine methacryloyl-co-allyl-2-(2,6-bis((E)-4-(diphenylamino)styryl)-4H-pyran-4-ylidene)-2-cyanoacetate) random copolymer, i.e., poly(NIPAAm-co-SPO-co-fluorophore), in water-in-oil (W/O) droplets is described.

Polymeric vehicles for topical delivery and related analytical methods.

Recently a variety of polymeric vehicles, such as micelles, nanoparticles, and polymersomes, have been explored and some of them are clinically used to deliver therapeutic drugs through skin. In topical delivery, the polymeric vehicles as drug carrier should guarantee non-toxicity, long-term stability, and permeation efficacy for drugs, etc. For the development of the successful topical delivery system, it is of importance to develop the polymeric vehicles of well-defined intrinsic properties, such as molecular weights, HLB, chemical composition, topology, specific ligand conjugation and to investigate the effects of the properties on drug permeation behavior.

Preparation of Fe₃O₄-Embedded Poly(styrene)/Poly(thiophene) Core/Shell Nanoparticles and Their Hydrogel Patterns for Sensor Applications.

This research describes the preparation and sensor applications of multifunctional monodisperse, Fe₃O₄ nanoparticles-embedded poly(styrene)/poly(thiophene) (Fe₃O₄-PSt/PTh), core/shell nanoparticles. Monodisperse Fe₃O₄-PSt/PTh nanoparticles were prepared by free-radical combination (mini-emulsion/emulsion) polymerization for Fe₃O₄-PSt core and oxidative seeded emulsion polymerization for PTh shell in the presence of FeCl₃/H₂O₂ as a redox catalyst, respectively. For applicability of Fe₃O₄-PSt/PTh as sensors, Fe₃O₄-PSt/PTh-immobilized poly(ethylene glycol) (PEG)-based hydrogels were fabricated by photolithography.

Cyclohexanediol bis-ethylhexanoate inhibits melanogenesis of murine B16 melanoma and UV-induced pigmentation in human skin.

The role of cyclohexane diester analogues in the formation of melanin has been recently reported. In the present study, we investigated the inhibitory effect of cyclohexanediol bis-ethylhexanoate (CHEH) on melanogenesis in B16 melanoma cells and on UV-B-induced pigmentation in human skin. CHEH significantly reduced the melanin content in a dose-dependent manner, without cytotoxic effects at the effective concentrations.

Topical delivery of retinol emulsions co-stabilised by PEO-PCL-PEO triblock copolymers: effect of PCL block length.

This article describes enhanced skin permeation and UV/thermal stability of retinol emulsions by the co-stabilisation of Tween20 and biodegradable poly(ethylene oxide)-block-poly(ε-caprolactone)-block-poly(ethylene oxide) (PEO-PCL-PEO) triblock copolymers having different lengths of hydrophobic PCL block. A triblock copolymer with a longer PCL block has a lower hydrophile-lipophile balance (HLB) value. Commercial Retinol 50C® (BASF Co.