Papers by Nutthira Pakkang
Lebensmittel-Wissenschaft & Technologie, Jun 1, 2014
Lignin extracts from sugarcane bagasse by alkaline extraction in the presence and absence of etha... more Lignin extracts from sugarcane bagasse by alkaline extraction in the presence and absence of ethanol were investigated for their efficacy on maintaining fresh fruit shelf life. For lignin extraction, the highest lignin yield was obtained from 40% (w/w) NaOH extraction in water. Addition of ethanol gave relatively lower yield of lignin but less hemicellulose contamination. FT-IR intensity of lignin-to-carbohydrate transmittance ratios of extracted lignin from 40% (w/w) NaOH in distilled water were similar to the ratios of lignin standard from Kraft process. From gel permeation chromatography (GPC), lignin isolated from 40% (w/w) NaOH in distilled water yielded high amount of both large and small molecules of lignin. The weight loss ratio between lignin and hemicellulose was analyzed by thermogravimetric analysis (TGA). It was confirmed that isolated lignin from 40% (w/w) NaOH in distilled water contained highest amount of hemicellulose in lignin extract. The test of coating formulas on limes demonstrated that coating solutions of 0.8% (w/w) xanthan gum and 1.5% (w/w) extracted lignin from 40% (w/w) NaOH had potential to maintain weight loss and color change. This coating formula also exhibited higher antifungal activities. Limes coated with extracted lignin showed higher antifungal activity than limes coated with commercial lignin.
Holzforschung, May 29, 2020
This article demonstrates the development of activated carbon fiber electrodes produced from hard... more This article demonstrates the development of activated carbon fiber electrodes produced from hardwood kraft lignin (HKL) to fabricate electric double layer capacitors (EDLCs) with high energy and power densities using an ionic liquid (IL) electrolyte. A mixture solution of HKL, polyethylene glycol as a sacrificial polymer, and hexamethylenetetramine as a crosslinker in dimethylformamide/acetic acid (6/4) was electrospun, and the obtained fibers were easily thermostabilized, followed by carbonization and steam activation to yield activated carbon fibers (ACFs). The electrochemical performance of EDLCs assembled with the ACFs, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF 4) as an IL electrolyte and a cellulosic separator was insufficient due to the low conductivity of the electrode. The conductivity of the electrode was improved successfully by spraying conductive carbon black (CB) onto the fibers mat during electrospinning. The CB containing electrodes with improved conductivity gave the resulting EDLCs a higher electrochemical performance, with an energy density of 91.5 Wh kg −1 and a power density of 76.2 kW kg −1 .
Journal of Wood Chemistry and Technology, Mar 25, 2019
This paper demonstrates direct electrospinning of two kinds of cellulose acetate, water-soluble c... more This paper demonstrates direct electrospinning of two kinds of cellulose acetate, water-soluble cellulose acetate (WSCA) and cellulose diacetate (CDA), onto a non-conductive synthetic polymer sheet to modify its surface morphology. Polyurethane (PU) sheets for polishing compact and hard disks were used as an example of synthetic polymer sheet. The direct electrospinning of WSCA 11 wt.% in aqueous ethanol solution (40 wt.%) and CDA 9 wt.% in aqueous acetone solution (90 wt.%), were carried out by spraying anti-static agent onto the sheet. However, the electrospun fibers were easily peeled off from the PU sheet. Tight fixation of the fibers was achieved by spraying a 50 wt.% of dimethylformamide/ethanol solution additionally during the spinning. Finally, the cellulose acetate fibers on the PU sheet were converted to regenerated cellulose fibers by leaving the fibers in an ammonia atmosphere for complete saponification. Change in surface morphology was evaluated by tribology test in addition to microscopic observations. Friction coefficient of PU sheet was dramatically decreased with increasing the amount of WSCA and CDA fibers deposited, suggesting that the PU sheet surface became smoother. Most of friction coefficients of the sheet were slightly increased by saponification, except for that of the PU sheet with increased amount of WSCA fibers, which might be attributed to the change in the elasticity upon saponification.
Journal of Surfactants and Detergents, Aug 13, 2018
Cosmetics accumulated in facial skin are difficult to remove by ordinary cleansers because they n... more Cosmetics accumulated in facial skin are difficult to remove by ordinary cleansers because they normally contain highly waterproof ingredients. Therefore, development of makeup remover products is necessary for the efficient removal of cosmetics without irritation to the skin. Current commercial makeup removers are emulsions produced from mineral oil and water with surfactants sometimes cause allergies and acne. To overcome these problems, vegetable oils seem to be promising ingredients for makeup removers. In this study, such makeup removers were prepared as water-in-oil (w/o) microemulsion from a mixture of castor oil and sunflower oil at ratios from 1:9 to 5:5 and water with nonionic surfactants, Span ® 80 and Dehydol LS ® TH. The remover candidates were selected with respect to transparency of emulsion and cleansing efficiency. As a result, an emulsion was prepared from a mixture of castor oil and sunflower oil with the ratio of 3:7, Dehydol LS ® TH with 7 repeating units of ethylene oxide, and 7.0% (w/w) of water. It was found that the stability of transparency and a high cleansing efficiency were attributed to the hydrophilicity of the surfactant and castor oil. Dynamic light-scattering analysis demonstrated that the emulsion consisted of nanoscale micelles, resulting in a microemulsion.
Advances in Natural Sciences: Nanoscience and Nanotechnology
In this study, lignin-based conducting carbon nanofiber mat was prepared by electrospinning follo... more In this study, lignin-based conducting carbon nanofiber mat was prepared by electrospinning followed by a thermal treatment. Lignin is a sustainable carbon precursor. Polyacrylonitrile (PAN) acts as a binder polymer, which increases the viscosity of the lignin solution using dimethylformamide solvent and helps in the formation of a stable nanofiber. The mixture solution was electrospun, followed by stabilisation and carbonisation to yield carbon nanofibers (CNFs). A fixed amount of external load was provided to the lignin fiber mat during the stabilisation procedure and then carbonised to yield stretched carbon nanofibers (S-CNFs). On stretching the mat, surface conductivity was enhanced by 3 times, and the surface area by 1.3 times compared to that of non-stretched CNFs. Finally, the electric double layer capacitor (EDLC) was assembled with the resulting (CNFs and S-CNFs) nanofiber mat using 6 M of KOH aqueous solution. S-CNFs mat exhibits a specific capacitance of 266 F g−1, which...
Holzforschung
This study aimed to assemble a high-performance electric double-layer capacitor (EDLC) using a ha... more This study aimed to assemble a high-performance electric double-layer capacitor (EDLC) using a hardwood kraft lignin (HKL)-based separator and HKL-based electrodes, which were fabricated from a nonwoven mat of electrospun HKL fibers. The separator was prepared by the thermostabilization of the mat derived from a mixed dope of HKL, hexamethylenetetramine, and polyethylene glycol (1.66/0.50/0.09, w/w) for electrospinning. Although a mat-type HKL-based electrode containing conductive carbon black (CB) has been reported to be suitable for a commercial cellulosic separator, this electrode was found to be unsuitable for the HKL-based separator because of its rough surface and poor contact with the separator interface. Hence, a powder-type electrode with a smooth surface was fabricated by grinding the mat, followed by casting with a carboxymethyl cellulose aqueous solution, and its EDLC possessed high energy (49 Wh kg−1) and power densities (151 kW kg−1). Moreover, to provide a simple proc...
Journal of Wood Chemistry and Technology, 2019
This article reports on direct electrospinning of water-soluble cellulose acetate (WSCA) and cell... more This article reports on direct electrospinning of water-soluble cellulose acetate (WSCA) and cellulose diacetate (CDA) onto a non-conductive synthetic polymer sheet such as polyurethane (PU) sheet to modify its surface morphology. The direct electrospinning was successfully performed after spraying an anti-static agent on the PU sheet. Furthermore, tight fixation of the fibers was achieved by spraying a dimethylformamide/ethanol (1/1) solution during the spinning. Finally, the cellulose acetate fibers on the PU sheet were converted to regenerated cellulose fibers by saponification. Changes in surface morphology were evaluated via tribology tests. The friction coefficient of the PU sheet significantly decreased with increases in the amount of deposited fiber, thereby suggesting that the PU sheet surface became smoother. After saponification, the friction coefficients of the sheets slightly increased, with the exception of the PU sheet with the increased amount of saponified WSCA fibe...
Holzforschung, 2020
This article demonstrates the development of activated carbon fiber electrodes produced from hard... more This article demonstrates the development of activated carbon fiber electrodes produced from hardwood kraft lignin (HKL) to fabricate electric double layer capacitors (EDLCs) with high energy and power densities using an ionic liquid (IL) electrolyte. A mixture solution of HKL, polyethylene glycol as a sacrificial polymer, and hexamethylenetetramine as a crosslinker in dimethylformamide/acetic acid (6/4) was electrospun, and the obtained fibers were easily thermostabilized, followed by carbonization and steam activation to yield activated carbon fibers (ACFs). The electrochemical performance of EDLCs assembled with the ACFs, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) as an IL electrolyte and a cellulosic separator was insufficient due to the low conductivity of the electrode. The conductivity of the electrode was improved successfully by spraying conductive carbon black (CB) onto the fibers mat during electrospinning. The CB containing electrodes with improved conductivi...
Journal of Surfactants and Detergents
Lebensmittel-Wissenschaft und-Technologie
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Papers by Nutthira Pakkang