Detsri, Ekarat
Loading...
9 results
Now showing 1 - 9 of 9
- Some of the metrics are blocked by yourconsent settings
Item type:Publication, Superhydrophobilization of SiO2 surface with two alkylsilanes for an application in oil/water separation(2018-04-01); ; This study reported a novel approach to superhydrophobilize silica (SiO<inf>2</inf>) surface by silanizing with two alkylsilanes including non-polar short hydrocarbon chains of chlorotrimethylsilane (CTMS) followed by long hydrocarbon chains of octadecyltrichlorosilane (OTS). The silanization of CTMS prior to OTS affected the increase in the density of short and long alkyl chains throughout SiO<inf>2</inf> surface resulting in the surface with low surface energy and high degree of hierarchical micro-nanoscale roughness which were responsible for the superhydrophobicity. The oil/water separation filters prepared by coating cotton fabric with the CTMS- and OTS-modified SiO<inf>2</inf>/polystyrene (PS) composite using a weight ratio of the modified SiO<inf>2</inf>:PS at 2:1 possessed the highest water contact angles of 156° ± 1°. The superhydrophobic/superoleophilic filters showed excellent water repellent, oil/water separation efficiency, and reusability. The results obtained in this study suggest that salinizing the two different structure alkylsilanes, CTMS followed by OTS, can provide synergetic benefit in improving the superhydrophobicity by enhancing the density of alkyl chains on SiO<inf>2</inf> surface. This alternative strategy can be extensively applied for development of other superhydrophobic materials. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, A sensitive and selective colorimetric sensor for reduced glutathione detection based on silver triangular nanoplates conjugated with gallic acid(2018-03-20); ; Silver triangular nanoplates conjugated with gallic acid (AgTNPs⋅GA) was designed and synthesized for colorimetric detection of reduced glutathione (GSH). The surface plasmon resonance (SPR) properties of AgTNPs⋅GA were strongly influenced by the addition of GSH. The detection principle was based on the aggregation of AgTNPs⋅GA, which leads to the significant bathochromic shift of the SPR spectra from 602 nm to 650 nm. The dramatic color changes from the initial dark blue to light blue can be observed, which allowed simple monitoring of GSH ether by naked eye and UV–vis spectrophotometer. With UV–vis spectrophotometer measurements, a quantitative linearity was established in the range of 0.5–5.0 nM (R<sup>2</sup> = 0.9919) and with a limit of detection (LOD) of 0.12 ± 0.02 nM. Relative standard deviation (RSD) of 3.46% and 1.82% (n = 10) were achieved for the determination of 1.0 and 3.0 nM, respectively. No interfering substances such as ascorbic acid, glucose, sucrose, citric acid, cysteine, Ca<sup>2+</sup>, Mg<sup>2+</sup>, Fe<sup>3+</sup> and K<sup>+</sup> were revealed in the AgTNPs⋅GA based assay. The proposed colorimetric strategy could be extended as the general platform for detection of GSH in dietary supplements and no significant differences in accuracy and precision were observed compared to HPLC standard method. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Microwave-assisted synthesis of unmodified gold nanoparticles for colorimetric detection of dopamine(2017-01-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Facile and eco-friendly fabrication of hierarchical superhydrophobic coating from eggshell biowaste(2019-01-01); ; This study reports a facile and sustainable approach to fabricate superhydrophobic coating from eggshell biowaste. The coating was prepared by ball milling chicken eggshells, composed of hydrophilic calcium carbonate (CaCO<inf>3</inf>), to microsized particles followed by surface hydrophobilizing with stearic acid (C<inf>17</inf>H<inf>35</inf>COOH) to form low surface energy nanosized calcium stearate ((C<inf>17</inf>H<inf>35</inf>COO)<inf>2</inf>Ca) through the esterification of hydroxyl groups (-OH) absorbed on a surface of CaCO<inf>3</inf> with carboxyl groups (–COOH) of stearic acid. Then, a layer of modified eggshell particles dispersed in polystyrene (PS) binder was dip-coated on a substrate. A coated surface with water contact angles of 151° ± 1° on glass and 153° ± 1° on cotton fabric substrates was achieved when a 4:1 weight ratio of the modified eggshell:PS was used. The uniform distribution of the modified eggshell particles throughout the coating led to a surface with high degree of hierarchical micro-nanoscale roughness which resulted in superhydrophobicity. The superhydrophobic eggshell coating showed good environmental stability, self-cleaning, and oil/water separation properties. These results suggest that eggshell biowaste can be utilized for superhydrophobic applications. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Nanostructured multilayer thin films of multiwalled carbon nanotubes/gold nanoparticles/glutathione for the electrochemical detection of dopamine(2016-10-01); - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Fabrication of silver nanoparticles/polyaniline composite thin films using Layer-by-Layer self-assembly technique for ammonia sensing(2015-02-01); Popanyasak, JittapornIn this study, the Layer-by-Layer (LbL) deposition technique was used to prepare composite thin films of silver nanoparticles and polyaniline. The multilayer composite thin films were constructed by alternate deposition of anionic and cationic polyelectrolytes. Anionic polyelectrolyte was prepared by chemical reduction of silver ion using water soluble polyaniline as the stabilizing agent to form anionic silver nanoparticles/polyaniline composite solution. The water soluble polyaniline was prepared by interfacial polymerization of aniline monomer in presence of poly(styrene sulfonic acid co maleic acid), (CoPSS). Silver nanoparticles stabilized with anionic water soluble polyaniline were then deposited in thin film with cationic poly(diallyldimethylammonium chloride), (PDADMAC) and characterized for their optical properties. The optical properties of thin films were measured by UV-visible spectroscopy. The surface of the films was measured by atomic force microscopy (AFM). As these films are to be used as sensor for the ammonia detection, the changes in optical properties of the films were evaluated for various ammonia concentration. A strong color shift from orange-red to yellow was visible when exposed to ammonia. These silver nanoparticles/polyaniline composite thin films displayed fast color change and could be used for ammonia sensing in industrial section. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Novel colorimetric sensor for mercury (II) based on layer-by-layer assembly of unmodified silver triangular nanoplates(2016-10-01)A simple layer-by-layer deposition technique was used to fabricate the multilayer thin films of unmodified silver triangular nanoplates (AgTNPs). The multilayer of AgTNPs thin films were fabricated by alternate deposition of each anionic sodium citrate stabilized AgTNPs and cationic poly(diallyldimethylammonium chloride). All prepared AgTNPs multilayer thin films were exhibited a strong plasmon band at the wavelength of 667 nm, which confirmed the formation of AgTNPs onto the substrate. The characteristics of the multilayer thin films were investigated using contact angle measurement, UV–visible spectroscopy, X-ray diffraction analysis (XRD), atomic force microscope (AFM) and field emission scanning electron microscope (FESEM). As these films are to be used as a mercury (II) colorimetric sensor, the changes in optical properties of the films were evaluated for various mercury (II) concentrations. AgTNPs assembled into thin films showed a strong color shift from blue to mauve and colorless when exposed to mercury (II). The constructed multilayer thin films exhibited excellent color changes of mercury (II) with a linear range between 0.5 and 20 ppm. The limit of detection (LOD) and limit of quantitation (LOQ) were 0.45 ± 0.002 and 1.52 ± 0.002 ppm, respectively. The recovery values of AgTNPs multilayer thin films are satisfactory in the range of 100.1%–106.4% when applied to determining mercury (II) in water samples. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Colorimetric detection of glutathione based on phthalic acid assisted synthesis of silver nanoparticles(2017-11-20); A new rapid, sensitive and selective colorimetric sensing platform for the detection of glutathione (GSH) in dietary supplements was developed by phthalic acid (PTA) assisted synthesis of silver nanoparticles (AgNPs). The di-carboxylic functional groups of PTA were used to modify the surface of AgNPs. The resulting AgNPs product was characterized by surface plasmon resonance (SPR) Ultraviolet–visible spectroscopy (UV–vis), Zeta potential analyzer, Fourietransform infrared spectroscopy (FT-IR), Transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD) techniques, demonstrated that PTA is an effective capping agent to stabilize AgNPs. AgNPs stabilized with PTA could cause the strong affinity to GSH. As the GSH concentration increased, the color of AgNPs solutions was gradually changed from yellow to orange and light purple as well as the SPR shifted from 400 nm to 556 nm upon an aggregation of AgNPs due to electrostatic interaction. The proposed colorimetric sensor was exhibited a linear response in the range of 0.1–100 nM (R<sup>2</sup> = 0.9992), with low detection limit (LOD) of 0.16 ± 0.01 nM. The sensor showed better precision with relative standard deviation (RSD) of 2.10% and 1.13% for ten repetitive measurements of 25 nM and 75 nM GSH solution, respectively. The sensitivity of AgNPs for GSH detection can be clearly differentiated towards other coexisting substances (Fe<sup>3+</sup>, Zn<sup>2+</sup>, Cu<sup>2+</sup>, K<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, glucose, sucrose, cysteine, ascorbic acid and citric acid). The AgNPs colorimetric sensor could discriminatively detect GSH in dietary supplement samples with the recoveries values in the range of 98.5%–103.0%. - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Layer-by-layer deposition of green synthesised silver nanoparticles on polyester air filters and its antimicrobial activity(2016-08-12);