RESUMEN
Electrowetting behaviour for carbon nanotubes (CNT) grown on stainless steel mesh was investigated. The effect of temperature, time, and applied bias voltage on the contact angle of water droplets was studied. The impact of temperature variation on contact angle was also performed for the temperature ranging from 25 to 70 °C. A decrement of contact angle by 68% was observed for the mentioned range indicating a transition from a hydrophobic to hydrophilic nature. A similar trend was observed on the application of electric potential to the CNT-modified stainless-steel mesh ranging from 0 to 8 V with a transition of contact angle from 146 to 30 deg respectively. A comparative analysis for the contact angle variation with time for CNT-coated mesh and uncoated mesh was performed for 180 min. It is observed that uncoated mesh shows a reduction in contact angle to 0 deg with time while the CNT coated mesh shows surplus hydrophobicity with a 2 deg decrement in the extent of time. CNT-modified mesh successfully absorbs 95% of rhodamine B (RB) dye and detergent from water in 10 cycles.
RESUMEN
This study presents a novel approach to fabricating interdigitated capacitive (IDC) touch sensors using graphite-based pencils on a wood substrate. The sensors were designed to detect touches and pressure variations, offering a cost-effective and environmentally friendly solution for sensor fabrication. The fabrication process involved abrasion of graphite pencils on a wooden substrate to create conductive traces, followed by the integration of interdigitated electrode structures. Capacitance variations resulting from touch interactions were investigated to calibrate sensor responses for tailored tasks. The sensitivity of the sensor was found to be 1.2 pF/kPa, highlighting its responsiveness to pressure variations. Additionally, the sensors were interfaced with an Arduino Uno microcontroller board to demonstrate practical applications, such as replicating arrow key functionality. Additionally, the sensors exhibit sensitivity to environmental factors, with the relative change in capacitance increasing from 0.1 to 0.65 as relative humidity ranges from 30 to 90%. Furthermore, variations in temperature from 30 to 60ºC result in a relative change in capacitance increasing to approximately 0.5. The results indicate the feasibility and versatility of using wood-based substrates and graphite-based pencils for fabricating IDC touch sensors, offering promising prospects for sustainable and accessible sensor technology.
RESUMEN
This study focuses on analyzing the poling effect of BaBi4Ti4O15 (BBT) on the basis of photo and piezo-catalysis performance. BBT powder is prepared via a solid state reaction followed by calcination at 950 °C for 4 h. BBT is characterized by an X-ray diffractometer, scanning electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. The optical bandgap of BBT is evaluated with the help of Tauc's plot and found to be 3.29 eV, which comes in the photon energy range of ultra-violet radiation. BBT powder is poled by using Corona poling in the presence of 2 kV mm-1 of electric field. An aqueous solution of methyl blue (MB) dye in the presence of UV radiation is used to evaluate the photo/piezocatalysis performance. Photocatalysis, piezocatalysis, and photo-piezo catalysis degradation efficiencies of poled and unpoled BBT powder are tested for 120 min of UV light irradiation. Photo-piezocatalysis shows degradation efficiencies of 62% and 40% for poled and unpoled BBT powder, respectively. Poling of BBT powder shows significant enhancement in degradation performance of MB dye in aqueous solution. Scavenger tests are also performed to identify reactive species.
RESUMEN
A thermoregulating smart textile based on phase change material (PCM) polyethylene glycol (PEG) was prepared by chemically grafting carboxyl-terminated PEG onto cotton. Further deposits of graphene oxide (GO) nanosheets were made on the PEG grafted cotton (PEG-g-Cotton) to improve the thermal conductivity of the fabric and to block harmful UV radiation. The GO-PEG-g-Cotton was characterized by Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, X-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS), and field emission-scanning electron microscopy (FE-SEM). With an enthalpy of 37 and 36 J/g, respectively, the DSC data revealed that the functionalized cotton's melting and crystallization maxima occurred at 58 °C and 40 °C, respectively. The thermogravimetric analysis (TGA) presented that GO-PEG-g-Cotton was thermally more stable in comparison to pure cotton. The thermal conductivity of PEG-g-Cotton increased to 0.52 W/m K after GO deposition, while pure cotton conductivity was measured as 0.045 W/m K. The improvement in the UV protection factor (UPF) of GO-PEG-g-Cotton was observed indicating excellent UV blocking. This temperature-regulating smart cotton offers a high thermal energy storage capability, better thermal conductivity, thermal stability, and excellent UV protection.
RESUMEN
The fabrication of a Poly (vinylidene fluoride) membrane (PVDF) and ceramic-assisted bismuth vanadate-polyvinylidene fluoride (BiVO4-PVDF) composite membrane was achieved through the utilization of the electrospinning technique. The composition and structure of the fabricated membranes were characterized by X-ray powder diffraction, Raman analysis, scanning electron microscopy, Thermo gravimetric analyzer, Fourier transform infrared spectroscopy, and UV-Vis spectroscopy techniques. The prepared polymeric membranes were then utilized for catalytic investigation and to explore, how structure affects catalytic activity using 5 mg/L, 10 mL methylene blue (MB) dye solution. Ultrasonication, visible light irradiation, and the combination were used to study piezocatalysis, photocatalysis, and piezo-photocatalysis, moreover, degradation intermediates were also explored using scavengers. Electrospun BiVO4-PVDF (BV-PVDF) composite has been found to have better piezocatalytic and photocatalytic properties than PVDF. The experimental findings reveal that the composite of BiVO4-PVDF demonstrates the highest efficiency in dye degradation, achieving a maximum degradation rate of 61% within a processing time of 180 min. The rate of degradation was calculated to be 0.0047 min-1, indicating a promising potential for the composite in the field of dye degradation.