Chemical modification of carbon fiber with diethylenetriaminepentaacetic acid/halloysite nanotube as a multifunctional interfacial reinforcement for silicone resin composites

In the present research, a multifunctional hierarchical reinforcement was prepared by chemical modification of carbon fibers (CFs) with halloysite nanotubes (HNTs) by the bridging diethylenetriaminepentaacetic acid (DTPA) for improving interfacial microstructures and properties of composites. Surface structures and groups of modified HNTs and CFs were characterized systematically. The uniform distributions of the introduced DTPA and HNTs helped to increase fiber polarity, surface energy, and wettability. As a consequence, significant enhancements of interfacial properties and hydrothermal aging resistance of composites were achieved, and interfacial reinforcing mechanisms have also been studied. Moreover, the storage modulus showed a 17.95% improvement, and the glass transition temperature was enhanced by 17°C by dynamic mechanical analysis testing.     

A Sensor for Serotonin and Dopamine Detection in Cancer Cells Line Based on the Conducting Polymer−Pd Complex Composite

An electrochemical sensor based on the conducting polymer composite with a palladium complex (Pd(C₂H₄N₂S₂)₂) was developed for the detection of serotonin and dopamine simultaneously in the breast cancer cell and human plasma samples. The proposed sensor was fabricated using the Pd(C₂H₄N₂S₂)₂ complex‐anchored poly2,2 : 5,2‐terthiophene‐3‐(p‐benzoic acid) (pTBA) layer on the AuNPs decorated reduced graphene oxide (AuNPs@rGO) substrate, which revealed the enhanced anodic current of the target species. The sensor probe was characterized by electrochemical and surface analysis methods. The experimental parameters affecting the sensor performance were optimized, in terms of AuNPs@rGO concentration, the number of electropolymerization cycle for pTBA, immobilization time of Pd(C₂H₄N₂S₂)₂, and pH. The dynamic ranges for serotonin and dopamine were obtained from 0.02 to 200 μM, and from 0.1 to 200 μM with the detection limit of 2.5, and 24.0 nM, respectively. The reliability of proposed sensor was evaluated using cancer cell lines for the clinical applications.     

Molecularly Imprinted Impedimetric Sensor for Determination of Mycotoxin Zearalenone

The mycotoxin zearalenone (ZEA) prompts reproductive toxicity due to its strong estrogenic effects. In this work, an electrochemical sensor for determination of ZEA was developed by electropolymerization of a molecularly imprinted poly (o‐phenylenediamine) (PPD) film on screen‐printed gold electrode (SPGE) surface. The sensor was examined by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using K₃[Fe(CN)₆]/K₄[Fe(CN)₆] as redox probe. The molecularly imprinted polymer (MIP) sensor showed a wide determination range from 2.50 to 200.00 ngmL^?1 for ZEA. The Limit of detection (LOD) was calculated to be 0.20 ngmL^?1, based on the signal to noise (S/N) ratio equal to 3.0. The sensor displayed good repeatability, with RSD values≤4.6 %, and maintained 93.2 % of its initial response after storage for 10 days in air at room temperature. The developed method was successfully applied for the determination of ZEA in corn flakes with mean recoveries ranged from 96.2 % to 103.8 % and RSDs within the interval of 2.1 % to 3.8 %.     

Synthesis of an Alternated Heterobimetallic Supramolecular Polymer Based on Ru(II) and Fe(II)

A heterobimetallic supramolecular polymer (polyRuFe) with alternately complexed Ru(II) and Fe(II) is prepared following a stepwise synthetic route through harnessing first the strongly binding metal ion Ru(II) and then the weakly binding metal ion Fe(II). A high yield of product is achieved in each step. The heterometal ions are incorporated into the polymer chain in identical coordination environments formed by two 2,2′:6′,2″-terpyridine moieties. Characterization is accomplished by NMR spectroscopy, MALDI–TOF mass spectrometry, UV–Vis spectroscopy, and cyclic voltammetry. PolyRuFe shows a wide optical window (λ = 311–577 nm) and a broad distinct reversible redox nature of two types, originated from the coupling of the two heterometallic segments into the polymer chain. Such characteristics of polyRuFe suggest its potential for various electrochemical and electro-optical applications.     

Dual‐Mode Antibacterial Conjugated Polymer Nanoparticles for Photothermal and Photodynamic Therapy

In this work, dual‐mode antibacterial conjugated polymer nanoparticles (DMCPNs) combined with photothermal therapy (PTT) and photodynamic therapy (PDT) are designed and explored for efficient killing of ampicillin‐resistant Escherichia coli (Amp^r E. coli). The DMCPNs are self‐assembled into nanoparticles with a size of 50.4 ± 0.6 nm by co‐precipitation method using the photothermal agent poly(diketopyrrolopyrrole‐thienothiophene) (PDPPTT) and the photosensitizer poly[2‐methoxy‐5‐((2‐ethylhexyl)oxy)‐p‐phenylenevinylene] (MEH‐PPV) in the presence of poly(styrene‐co‐maleic anhydride) which makes nanoparticles disperse well in water via hydrophobic interactions. Thus, DMCPNs simultaneously possess photothermal effect and the ability of sensitizing oxygen in the surrounding to generate reactive oxygen species upon the illumination of light, which could easily damage resistant bacteria. Under combined irradiation of near‐infrared light (550 mW cm^?2, 5 min) and white light (65 mW cm^?2, 5 min), DMCPNs with a concentration of 9.6 × 10^?4 µm could reach a 93% inhibition rate against Amp^r E. coli, which is higher than the efficiency treated by PTT or PDT alone. The dual‐mode nanoparticles provide potential for treating pathogenic infections induced by resistant microorganisms in clinic.     

Polymer Transformers: Interdigitating Reaction Networks of Fueled Monomer Species to Reconfigure Functional Polymer States

Adaptivity is an essential trait of life. One type of adaptivity is the reconfiguration of a functional system states by correlating sensory inputs. We report polymer transformers, which can adaptively reconfigure their composition from a state of a mixed copolymer to being enriched in either monomer A or B. This is achieved by embedding and hierarchically interconnecting two chemically fueled activation/deactivation enzymatic reaction networks for both monomers via a joint activation pathway (network level) and an AB linker monomer reactive to both A and B (species level). The ratio of enzymes governing the individual deactivation pathways (our external signals) control the enrichment behavior in the dynamic state. The method shows high programmability of the reconfigured state, rejuvenation of transformation cycles, and quick in situ adaptation. As a proof‐of‐concept, we showcase this dynamic reconfiguration for colloidal surface functionalities.     

Ordered Solid‐State Microstructures of Conjugated Polymers Arising from Solution‐State Aggregation

Controlling the solution‐state aggregation of conjugated polymers for producing specific microstructures remains challenging. Herein, a practical approach is developed to finely tune the solid‐state microstructures through temperature‐controlled solution‐state aggregation and polymer crystallization. High temperature generates significant conformation fluctuation of conjugated backbones in solution, which facilitates the polymer crystallization from solvated aggregates to orderly packed structures. The polymer films deposited at high temperatures exhibit less structural disorders and higher electron mobilities (up to two orders of magnitude) in field‐effect transistors, compared to those deposited at low temperatures. This work provides an effective strategy to tune the solution‐state aggregation to reveal the relationship between solution‐state aggregation and solid‐state microstructures of conjugated polymers.     

Phospholipid Polymer Hydrogel Matrices with Dually Immobilized Cytokines for Accelerating Secretion of the Extracellular Matrix by Encapsulated Cells

Construction of 3D tissues by various types of cells with specific characteristics is an important and fundamental technology in tissue reconstruction medicine and animal‐free diagnosis system. To do so, an excellent extracellular matrix (ECM) is needed for encapsulation of cells and maintaining cell activity. Spontaneously forming hydrogel matrix is used by complexation between two water‐soluble polymers, 2‐methacryloyloxyethyl phosphorylcholine polymer bearing phenylboronic acid groups and poly(vinyl alcohol). Two cytokines for cell proliferation are immobilized in the hydrogel matrix to control the activities of the encapsulated cells. The cytokine‐immobilized hydrogel matrix can encapsulate both L929 fibroblasts and normal human dermal fibroblasts under mild condition. The physical properties of the hydrogel matrix can follow the proliferation process of the encapsulated cells. The encapsulated cells secrete ECM in the polymer hydrogel networks upon 3D culturing for 7 days. Consequently, the tissue‐mimicking ECM hybrid hydrogels are fabricated successfully.     

Impact of ionic liquids on silver thermoplastic polyurethane composite membranes for propane/propylene separation

This work describes newly synthesized composite polymeric membranes and their utilization in propane/propylene separation in a gas mixture. The nonporous composite polymers were successfully synthesized by using thermoplastic polyurethane (TPU) and several silver salts/silver salts with ionic liquids (ILs). Our studies showed that silver bis(trifluoromethanesulfonyl)imide (Ag[Tf₂N]) containing membranes outperformed other silver salt containing membranes in terms of selectivity. In addition, to this finding, ILs, as additives for the membranes, enhanced the selectivity by facilitating improved coordination of the olefin with the silver ions in the dense composite polymers.