Enhanced Electrical and Mechanical Properties of Silver Nanoplatelet-Based Conductive Features Direct Printed on a Flexible Substrate

Noncontact direct printed conductive silver patterns with an enhanced flexural and bending strength and a proper electrical resistivity were fabricated using silver nanoplatelet inks without any surfactants for particle dispersion on a polyimide film. The microstructure, electrical resistivity, and bending strength of conductive features based on the nanoplatelets are systematically investigated and compared to nanoparticles to demonstrate superior properties. Nanoplatelets stack neatly on the substrate after noncontact direct printing, which minimizes void formation during sintering. This microstructure results in excellent resistivity on external repetitive bending stress as well as sufficiently lower electrical resistivity. It is believed to be a general conductive material to fabricate the noncontact direct printed conductive patterns with excellent mechanical stability for various flexible electronics, including solar cells, displays, RFID, and sensors

Novel Concept for Fabricating a Flexible Transparent Electrode Using the Simple and Scalable Self-Assembly of Ag Nanowires

We introduce a new concept for transparent electrodes via the self-assembly of a silver nanowire (Ag NW) network with a cell shape. A transparent conductive network was achieved by forming an array of Ag NWs around droplets of a solvent with higher vapor pressure in Ag NWs ink. The difference in vapor pressure and viscosity of the solvent causes an Ag NWs network with a cell shape, and the cell size can be easily controlled from 10 to 100 μm using the solvent ratio. The cell network of Ag NWs with a high optical transmittance (>92%) and low sheet resistance (40 Ω/sq) was simply fabricated on flexible polymer films of large scale using a Meyer rod coating. In addition, we also studied and demonstrated the figure of merit of the transparent electrode between our method and a random Ag NWs network from the general method. The performance of the transparent electrode may be applied to a wide array of optoelectronic devices and can replace transparent conductive oxides such as Al-doped ZnO and indium tin oxide

Novel Concept for Fabricating a Flexible Transparent Electrode Using the Simple and Scalable Self-Assembly of Ag Nanowires

We introduce a new concept for transparent electrodes via the self-assembly of a silver nanowire (Ag NW) network with a cell shape. A transparent conductive network was achieved by forming an array of Ag NWs around droplets of a solvent with higher vapor pressure in Ag NWs ink. The difference in vapor pressure and viscosity of the solvent causes an Ag NWs network with a cell shape, and the cell size can be easily controlled from 10 to 100 μm using the solvent ratio. The cell network of Ag NWs with a high optical transmittance (>92%) and low sheet resistance (40 Ω/sq) was simply fabricated on flexible polymer films of large scale using a Meyer rod coating. In addition, we also studied and demonstrated the figure of merit of the transparent electrode between our method and a random Ag NWs network from the general method. The performance of the transparent electrode may be applied to a wide array of optoelectronic devices and can replace transparent conductive oxides such as Al-doped ZnO and indium tin oxide

Tailored Synthesis of Photoactive TiO₂ Nanofibers and Au/TiO₂ Nanofiber Composites: Structure and Reactivity Optimization for Water Treatment Applications

Titanium dioxide (TiO₂) nanofibers with tailored structure and composition were synthesized by electrospinning to optimize photocatalytic treatment efficiency. Nanofibers of controlled diameter (30–210 nm), crystal structure (anatase, rutile, mixed phases), and grain size (20–50 nm) were developed along with composite nanofibers with either surface-deposited or bulk-integrated Au nanoparticle cocatalysts. Their reactivity was then examined in batch suspensions toward model (phenol) and emerging (pharmaceuticals, personal care products) pollutants across various water qualities. Optimized TiO₂ nanofibers meet or exceed the performance of traditional nanoparticulate photocatalysts (e.g., Aeroxide P25) with the greatest reactivity enhancements arising from (i) decreasing diameter (i.e., increasing surface area), (ii) mixed phase composition [74/26 (±0.5) % anatase/rutile], and (iii) small amounts (1.5 wt %) of surface-deposited, more so than bulk-integrated, Au nanoparticles. Surface Au deposition consistently enhanced photoactivity by 5- to 10-fold across our micropollutant suite independent of their solution concentration, behavior that we attribute to higher photocatalytic efficiency from improved charge separation. However, the practical value of Au/TiO₂ nanofibers was limited by their greater degree of inhibition by solution-phase radical scavengers and higher rate of reactivity loss from surface fouling in nonidealized matrixes (e.g., partially treated surface water). Ultimately, unmodified TiO₂ nanofibers appear most promising for use as reactive filtration materials because their performance was less influenced by water quality, although future efforts must increase the strength of TiO₂ nanofiber mats to realize such applications

Enhanced capacitive pressure sensing performance by charge generation from filler movement in thin and flexible PVDF-GNP composite films

This study introduces an approach to overcome the limitations of conventional pressure sensors by developing a thin and lightweight composite film specifically tailored for flexible capacitive pressure sensors, with a particular emphasis on the medium and high-pressure range. To accomplish this, we have engineered a composite film by combining polyvinylidene fluoride (PVDF) and graphite nanoplatelets (GNP) derived from expanded graphite (Ex-G). The uniform sized GNP with average lateral size of 2.55av and the average thickness of 33.74 av with narrow size distribution was obtained a gas induced expansion of expandable graphite (EXP-G) combined with tip sonication in solvent. By this precisely controlled GNP within the composite film, a remarkable improvement in sensor sensitivity has been achieved, surpassing 4.18 MPa−1 within the pressure range of 0.1 to 1.6 MPa. This enhancement can be attributed to the generation of electric charge from the movement of GNP in polymer matrix. Additionally, stability testing has demonstrated the reliable operation of the composite film over 1000 cycles. Notably, the composite film exhibits exceptional continuous pressure sensing capabilities with a rapid response time of approximately 100 milliseconds. Experimental validation using a 3 × 3sensor array has confirmed the accurate detection of specific contact points, thus highlighting the potential of the composite film for selective pressure sensing. These findings signify an advancement in the field of flexible capacitive pressure sensors that offer enhanced sensitivity, consistent operation, rapid response time, and the unique ability to selectively sense pressure. Our study provide the effect of GNP in polymer composite system with a facile and easy process, to enhance the capacitive pressure sensing properties, particularly at high pressure range applications.</p