The effect of heteroatom conformation on optoelectronic properties of cyclopentadithiophene derivatives.

Cyclopentadithiophene (CPDT) derivatives with different heteroatom conformations have been synthesized. The optical, electrochemical and charge transport properties of these molecules are reported. The CPDT-anti-ketone not only exhibits the lowest optical and electronic bandgaps, but also exhibits reasonable hole mobility, 3 × 10(-3) cm(2) (V s)(-1). Changing the carbonyl conformation to the syn position or incorporating the imine functionality results in a blue-shift in the lower energy band of the absorption spectrum indicative of the increased bandgaps.

Assessing the Potential of Gallic Acid and Methyl Gallate to Enhance the Efficacy of ß-Lactam Antibiotics against Methicillin-Resistant Staphylococcus aureus by Targeting ß-Lactamase: In Silico and In Vitro Studies.

Methicillin-resistant Staphylococcus aureus (MRSA), a global health concern, has prompted research into antibiotic adjuvants as a potential solution. Although our group previously reported the enhancing effects of gallic acid (GA) and methyl gallate (MG) on penicillin G activity against MRSA, the synergistic potential with other ß-lactam antibiotics and the underlying mechanism have not been fully explored. Therefore, this study primarily aimed to investigate the antibacterial synergism with ß-lactam antibiotics through disc diffusion, checkerboard, and time-kill assays. The ß-lactamase inhibition was also examined through both molecular modeling and in vitro experiments. Additionally, bacterial morphology changes were studied using a scanning electron microscopy (SEM). The results revealed that both GA and MG exhibited anti-MRSA activity and showed indifferent effects when combined with ß-lactam antibiotics against methicillin susceptible S. aureus (MSSA). Interestingly, MG demonstrated synergism with only the ß-lactamase-unstable antibiotics against MRSA with the lowest fractional inhibitory concentration (FIC) indexes of ≤3.75. However, GA and MG exhibited weak ß-lactamase inhibition. Furthermore, GA, MG, and the combination with ampicillin induced the morphological changes in MRSA, suggesting a possible mechanism affecting the cell membrane. These findings suggest that MG could potentially serve as an adjunct to ß-lactam antibiotics to combat MRSA infections.

Electrospun Cyclodextrin/Poly(L-lactic acid) Nanofibers for Efficient Air Filter: Their PM and VOC Removal Efficiency and Triboelectric Outputs.

In this work, PLLA and CD/PLLA nanofibers were fabricated using electrospinning and utilized as a particulate matter (PM) and volatile organic compounds (VOCs) filter. The electrospun PLLA and CD/PLLA were characterized with various techniques, including SEM, BET, FTIR, XRD, XPS, WCA, DSC, tensile strength testing, PM and VOCs removal efficiency, and triboelectric performance. The results demonstrated that the best air filter was 2.5 wt%CD/PLLA, which performed the highest filtration efficiencies of 96.84 ± 1.51% and 99.38 ± 0.43% for capturing PM2.5 and PM10, respectively. Its PM2.5 removal efficiency was 16% higher than that of pure PLLA, which were contributed by their higher surface area and porosity. These 2.5 wt%CD/PLLA nanofibers also exhibited the highest and the fastest VOC entrapment. For triboelectric outputs, the 2.5 wt%CD/PLLA-based triboelectric nanogenerator provided the highest electrical outputs as 245 V and 84.70 µA. These give rise to a three-fold enhancement of electrical outputs. These results indicated that the 2.5 wt%CD/PLLA can improve surface charge density that could capture more PM via electrostatic interaction under surrounding vibration. Therefore, this study suggested that 2.5 wt%CD/PLLA is a good candidate for a multifunction nanofibrous air filter that offers efficient PM and VOC removal.

Electrospun silk nanofiber loaded with Ag-doped TiO2 with high-reactive facet as multifunctional air filter.

Particulate matter (PM) and volatile organic compounds (VOCs) are air pollution that can cause high risk to public health. To protect individuals from air pollution exposure, fibrous filters have been widely employed. In this work, we develop silk nanofibers, which are loaded with Ag-doped TiO2 nanoparticles with exposed (001) (assigned as Ag-TiO2-silk), via electrospinning method and utilized them as multifunctional air filters that can efficiently reduce PM2.5, organic pollutants and microbials. The results showed that Ag-TiO2-silk with a loading of 1 wt% (1%Ag-TiO2-silk) exhibited the best performance among various different Ag-doped samples, as it performed the best as an air filter, which had the highest PM2.5 removal efficiency of 99.04 ± 1.70% with low pressure drop of 34.3 Pa, and also exhibited the highest photodegradation efficiency of formaldehyde. In addition, the Ag-TiO2-silk demonstrated antibacterial activity. These properties make silk composite nanofibers attractive for multifunctional and environmentally-friendly air filter application.

Natural textile based triboelectric nanogenerators for efficient energy harvesting applications.

This work reports a facile method to create efficient natural textile based triboelectric nanogenerators (N-TENGs). First, plain natural textiles, cotton and silk, were dip-coated in cyanoalkyl silane and fluoroalkyl silane to transform their surface energy into positive and negative triboelectricity. The N-TENGs were fabricated by stacking an cyanoalkylated siloxane grafted fabric with an fluoralkylated siloxane grafted fabric to assemble a Cu fabric electrode. A single N-TENG generated a maximum output voltage and output current of 216.8 V and 50.3 µA (0.87 µA cm-2), without any nanopatterning. The double stacked N-TENG showed an enhanced output current of 84.8 µA (1.46 µA cm-2), and exhibited a maximum power output of 0.345 mW cm-2 at an external resistance of 0.42 MΩ. In addition, the N-TENG can light up 100 light-emitting diodes (LEDs) and charge capacitors, demonstrating its self-powering applications.

Improved Performance of Ternary Solar Cells by Using BODIPY Triads.

Two boron dipyrromethene (BODIPY) triads, namely BODIPY-1 and BODIPY-2, were synthesized and incorporated with poly-3-hexyl thiophene: (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) P3HT:PCBM. The photovoltaic performance of BODIPY:P3HT:PCBM ternary solar cells was increased, as compared to the control binary solar cells (P3HT:PCBM). The optimized power conversion efficiency (PCE) of BODIPY-1:P3HT:PCBM was improved from 2.22% to 3.43%. The enhancement of PCE was attributed to cascade charge transfer, an improved external quantum efficiency (EQE) with increased short circuit current (Jsc), and more homogeneous morphology in the ternary blend.

Wash-stable, oxidation resistant conductive cotton electrodes for wearable electronics.

Commercial, untreated cotton fabrics have been directly silver coated using one-step electroless deposition and, subsequently, conformally encapsulated with a thin layer of poly(perfluorodecylacrylate) (PFDA) using initiated chemical vapor deposition (iCVD). The surface of these PFDA encapsulated fabrics are notably water-repellent while still displaying a surface resistance as low as 0.2 Ω cm-1, making them suitable for incorporation into launderable wearable electronics. X-ray photoelectron spectroscopy confirms that the PFDA encapsulation prevents oxidation of the silver coating, whereas unencapsulated samples display detrimental silver oxidation after a month of air exposure. The wash stability of PFDA-encapsulated, silver-coated cotton is evaluated using accelerated laundering conditions, following established AATCC protocols, and the samples are observed to withstand up to twenty home laundering cycles without notable mechanical degradation of the vapor-deposited PFDA encapsulation. As a proof-of-concept, PFDA-Ag cotton is employed as a top and bottom electrode in a layered, all-fabric triboelectric generator that produces voltage outputs as high as 25 V with small touch actions, such as tapping.

BODIPY dyads and triads: synthesis, optical, electrochemical and transistor properties.

A series of D-A dyads and D-A-D triads molecular systems based on triphenylamine and 9-ethyl-carbarzole as donor (D) and BODIPY as acceptor (A) has been designed and synthesized. The optoelectronic properties including optical, electrochemical, and charge carrier mobility of these molecules have been investigated. We found that the D-A-D triads exhibited broader absorption, raising the HOMO energy levels and increase hole carrier mobilities. Analysis surface morphology revealed that BODIPY containing carbazole demonstrated smooth film and no macro phase aggregation was observed upon thermal annealing.

The effect of co-sensitization methods between N719 and boron dipyrromethene triads on dye-sensitized solar cell performance.

A boron dipyrromethene (BODIPY) featuring triphenylamine triad, BD, has been synthesized as a co-sensitizer in dye-sensitized solar cells (DSCs). The optical and electrochemical properties of BD have been characterized using UV-vis spectroscopy and cyclic voltammetry. DSCs containing co-sensitizers, N719 and BD, have been prepared in two procedures using co-deposition and stepwise deposition. The influences of the staining processes, co-deposition and stepwise deposition on dye loading, dye dispersion on a TiO2 photoanode and DSC performance have been investigated using FTIR, SEM-EDS, I-V test and IPCE measurement, respectively. We found that stepwise co-sensitization provided higher solar cell efficiency, compared to those stained with a co-deposition method. N719/5% BD showed the highest power conversion efficiency of 5.14%. Interestingly, the enhanced device efficiency was 66% higher than that of a device containing the single N719 dye.