Chiravoot Pechyen - Academia.edu (original) (raw)

Papers by Chiravoot Pechyen

International journal of precision engineering and manufacturing. Green engineering/International journal of precision engineering and manufacturing green technology, Jan 31, 2024

PLOS ONE

Monitoring the level of glycated hemoglobin (HbA1c) has become the gold standard measure for diab... more Monitoring the level of glycated hemoglobin (HbA1c) has become the gold standard measure for diabetes mellitus (DM) diagnosis and control, used in conjunction with fasting blood glucose (FBG) and oral glucose tolerance test. This study aimed to investigate the applicability of a newly developed nanoparticle-based electrochemical sensor—multiwalled nanotubes incorporated with gold nanoparticles (POCT-HbA1cMWCNTs/AuNPs)—used as a routine point-of-care test (POCT) for detection of HbA1c for the diagnosis of DM. Finger-prick and venous blood samples were collected from 108 DM and 98 non-DM subjects to determine HbA1c and total hemoglobin by POCT-HbA1cMWCNTs/AuNPs compared with the standard HPLC method. The performance of the POCT-HbA1cMWCNTs/AuNPs was evaluated using the standard cut-off HbA1c level of >6.5%. The test’s sensitivity, specificity, positive predictive value, and negative predictive value were 100.00%, 90.32%, 87.23%, and 100.00%, respectively. The probability of DM diag...

medRxiv (Cold Spring Harbor Laboratory), Oct 21, 2022

Monitoring the level of glycated hemoglobin (HbA1c) has become the gold standard measure of diabe... more Monitoring the level of glycated hemoglobin (HbA1c) has become the gold standard measure of diabetes mellitus diagnosis and control in conjunction with FBG and oral glucose tolerance test. The study aimed to investigate the applicability of the newly developed nanoparticle-based electrochemical biosensor-multiwalled nanotubes corporated with gold nanoparticles (POCT-HbA1cMWCNTs/AuNPs) as a routine POCT for detection of HbA1c for the diagnosis of diabetes mellitus (DM). Finger-prick and venous blood samples were collected 108 DM and 98 non-DM subjects for determination of HbA1c and total hemoglobin by POCT-HbA1cMWCNTs/AuNPs in comparison with standard HPLC method. The performance of the POCT-HbA1cMWCNTs/AuNPs was evaluated using the standard cutoff HbA1c level of >6.5%. The sensitivity, specificity, positive predictive value, and negative predictive value of the test were 100.00%, 90.32%, 87.23%, and 100.00%, respectively. The probability of DM diagnosis in a subject with HbA1c >6.5 (positive predictive value) was 87.23% (82/94). The accuracy of the POCT-HbA1cMWCNTs/AuNPs was 94.18%, with %DMV (deviation of the mean value) of 0.25%. The results indicate satisfactory assay performance and applicability of the POCT-HbA1cMWCNTs/AuNPs for diagnosis of DM using the cutoff criteria of HbA1c >6.5. .

Polymer Bulletin, 2016

Isotactic polypropylene (PP) composite films were developed, with incorporation of CaCO 3 particl... more Isotactic polypropylene (PP) composite films were developed, with incorporation of CaCO 3 particles as active filler. Stearic acid was used for the surface treatment of CaCO 3 to provide composite films having improved mechanical, thermal and barrier properties against oxygen as well as water vapor, in comparison to neat PP films. The filler was melt mixed with PP in a twin-screw extruder, and the films produced through melt blowing. A slight reduction in T g values of the filled PP films was observed, along with an increase in the overall crystallization extent relative to neat PP films. X-ray diffraction data confirmed that the CaCO 3 particles served as a b-nucleating agent capable of promoting the formation of the b-crystalline phase of PP and reducing the spherulite size, with stearic acid-coated CaCO 3 being most effective in promoting these features. Exposing the films to microwave radiation altered their properties; at low irradiation power, the T g values and the degree of b-crystallization were enhanced, and barrier properties against oxygen and water vapor showed improvements. In contrast, no significant changes in the appearance of the film surface were evident highlighting the potential of these PP-based composite films in microwave packaging applications.

Colloid and Polymer Science, 2016

Nylon 6 and its modification as a compound have been employed in several applications such as in ... more Nylon 6 and its modification as a compound have been employed in several applications such as in the textile industry. To gain effectiveness in textile applications, nylon 6's self-cleaning and antibacterial properties were modified. ZnO was successfully synthesized using a wet chemical synthetic procedure. The thermal decomposition of the ZnO precursor was investigated using thermogravimetric analysis. The calcination temperature was set to be 500-1000°C for 2 h. Decomposition products of the organic phase were removed at temperatures ranging from 300 to 500°C. X-ray diffraction and scanning electron microscopy showed the single phase of ZnO and the variable-sized hexagonal-shaped cross-section, respectively. With incremental increases in the calcination temperature, there was no residue from char, and agglomeration of the ZnO increased. The ZnO was dispersed in methanol and subsequently spin-coated onto a nylon 6 surface. The efficiency of ZnO coating on the nylon 6 surface was investigated by the photocatalytic activity of methylene blue degradation. The apparent rate constant was estimated to be 0.5 by the Langmuir-Hinshelwood equation. The photocatalytic activity of ZnO coated on nylon 6 exhibited excellent performance for wastewater treatment in the textile industry.

Russian Journal of Applied Chemistry, 2016

Renewable and Sustainable Energy Reviews, 2016

The use of bio-based waste gained many interests exponentially for supporting on the use of non-t... more The use of bio-based waste gained many interests exponentially for supporting on the use of non-toxic materials. During the last three decades, bio-based waste in form of bio-based polymer and bio-based ceramic such as cellulose, chitin-chitosan, porous clay, eggshell, activated carbon and so on have been extensively designed for being as sorbent material. The use of bio-based waste was encourages due to low cost of materials and availability of product. Moreover, due to sustainable concept on the use of biobased waste, numerous innovative processes have been extensively employed to modify on surface and structure in order to tailor the excellent performance as sorbent material. The example of process was due to chemical treatment and physical modification. Additional information on bio-based sorbent material will provide significant idea on energy policy in future. In this review article, the objective was to present on the overview on bio-based waste and its modification technique and the potential application as sorbent material for energy policy will be discussed.

Journal of Biobased Materials and Bioenergy, 2017

Applied Clay Science, 2016

Fish water soluble protein (FWSP) film from the surimi washing process was prepared by solvent ca... more Fish water soluble protein (FWSP) film from the surimi washing process was prepared by solvent casting. The results demonstrated that FWSP-oleic acid had the highest tensile strength (TS) and elongation at break (%E) at 12.11 ± 2.39 MPa and 7.14 ± 3.17% respectively. Water vapor permeability (WVP) of FWSP-oleic acid was higher than FWSP-palmitic acid at 5.27 ± 0.50 × 10 −11 g m/m 2 s Pa. On the contrary, FWSP-oleic acid had the lowest oxygen permeability (OP) at 2.34 ± 0.14 cm 3 mm/m 2 d k Pa. FWSP-oleic acid with Mt content 5 g/ 100 g FWSP presented the lowest WVP. High amount of Mt loading resulted in an increase in the WVP and OP. The melting (T m) temperature of FWSP-oleic acid was~107°C but FWSP-stearic acid and FWSP-palmitic acid had two T m levels were~73°C~122°C and~88°C~127°C, respectively. FWSP-oleic acid with Mt content 5 g/100 g FWSP had the highest T m level at~113°C. The thermal stability of the films increased from~349 tõ 357°C with the addition of Mt content 20 g/100 g FWSP. The changes observed in the intensity of the bands corresponded to the amine group. It showed that FWSP interacts with Mt.

International Journal of Polymer Science, 2016

Bacterial cellulose and eggshell composite was successfully developed. Eggshell was mixed with ba... more Bacterial cellulose and eggshell composite was successfully developed. Eggshell was mixed with bacterial cellulose suspension and it was casted as a composite film. CaCO3derived from eggshell was compared with its commercial availability. It can be noted that good dispersion of eggshell particle was prepared. Eggshell particle was irregular in shape with a variation in size. It existed in bacterial cellulose network. Characterization on composite was focused on thermal and mechanical properties. It showed that flexibility and thermal stability of composite were enhanced. No significant effect of mechanical properties was therefore observed. The thermal stability of composite was stable up to 300°C. The adsorption experiment on water and vegetable oil capacity was performed. The enhancement on adsorption was due to the existence of eggshell in bacterial cellulose composite. It exhibited the potential to be a good candidate for absorbent material in active packaging.

Carbohydrate Polymers, 2016

Cellulose based composite was successfully designed as active packaging with additional feature o... more Cellulose based composite was successfully designed as active packaging with additional feature of microwavable properties. Small amount of cellulose with 10 micron in diameter was integrated into polypropylene matrix. The use of maleic anhydride was employed as coupling agent. Thermal and mechanical properties of cellulose based composite were superior depending on polypropylene matrix. Crystallization temperature and compressive strength were estimated to be 130°C and 5.5 MPa. The crystal formation and its percentage were therefore estimated to be 50% and it can be predicted on the feasibility of microwavable packaging. Morphological properties of cellulose based composite presented the good distribution and excellent uniformity. It was remarkable to note that cellulose derived from cotton can be prepared as composite with polypropylene matrix. It can be used as packaging for microwave application.

Molecules

This work aimed to study the influence of the polybutylene succinate (PBS) content on the physica... more This work aimed to study the influence of the polybutylene succinate (PBS) content on the physical, thermal, mechanical, and chemical properties of the obtained polylactic acid (PLA)/PBS composite fibers. PLA/PBS blend fibers were prepared by a simple melt-blown process capable of yielding nanofibers. Morphological analysis revealed that the fiber size was irregular and discontinuous in length. Including PBS affected the fiber size distribution, and the fibers had a smoother surface with increased amounts of added PBS. Differential scanning calorimetry analysis (DSC) revealed that the crystallization temperature of the PLA sheet (105.8 °C) was decreased with increasing PBS addition levels down to 91.7 °C at 10 wt.% PBS. This suggests that the addition of PBS may affect PLA crystallization, which is consistent with the X-ray diffraction analysis that revealed that the crystallinity of PLA (19.2%) was increased with increasing PBS addition up to 28.1% at 10 wt% PBS. Moreover, adding P...

Energy & Fuels, Sep 21, 2007

Use of waste as raw material for producing porous carbon was investigated in this work. Physic nu... more Use of waste as raw material for producing porous carbon was investigated in this work. Physic nut (Jatropha curcas L.) residue from oil extraction for biodiesel production was pyrolyzed at 400-800°C with hold times of 15, 120, and 240 min to obtain char precursors. Activated carbon, with favorable Brunauer-Emmett-Teller surface area in a narrow range, was prepared by soaking these chars in concentrated KOH, H 3 PO 4 , as well as a pure CO 2 gas flash activator. The maximum specific surface area of 532.30 m 2 g-1 was developed for the alkaline-treated sample. The carbon fraction of activated materials was as much as 90 wt %, significantly higher than the char precursor. Mesopore of 2-50 nm and total pore volumes of the materials were also significantly enhanced by these activations. Nitrogen adsorption isotherms of physic-nut-waste-activated carbons indicated that they were mainly mesopores. Pores of char activated by KOH and H 3 PO 4 are irregular, of different shapes and sizes, and the macropores seemed to be connected to mesopores, especially for the KOHactivated case. Surface analysis of pyrolyzed and activated char using Fourier transform infrared spectroscopy indicated main functional groups that are considerably different to those of activated materials, which may lead to greater adsorption potential of activated samples. However, functional groups on each activated carbon are quite similar even with different activation processes. According to the data obtained, physic nut residue pyrolyzed at 800°C and followed by KOH activation could be used as a low-cost adsorbent with favorable surface properties.

The effect of polypropylene/poly(lactic acid) weight ratios on the properties of blend films comp... more The effect of polypropylene/poly(lactic acid) weight ratios on the properties of blend films compatilized with polypropylenegrafted-maleic anhydride were investigated with 100:0, 60:40, 50:50, 40:60, and 0:100 of weight ratio. The blend films were prepared by melt mixing technique and cast film extrusion. The results shown that the FTIR spectrum was confirmed the interaction between compatibilizer and polymers. Morphological investigation was distinctly seen a two phases system between polypropylene and poly(lactic acid). Increasing of PLA content from 40 to 60 wt.% resulting in decreased melting temperature and crystallinity from 158 °C to 154 °C and 38% to 31%, respectively. For tensile properties, modulus and tensile strength increased with increasing the PLA content, while elongation at break was drastically decreased from 500% (polypropylene) to less than 50% (blends). The barrier properties indicated that incorporation of poly(lactic acid) into polypropylene tend to increased ...

Energy and Sustainability II, 2009

Pyrolysis of physic nut residues was conducted under isothermal and dynamic heating conditions in... more Pyrolysis of physic nut residues was conducted under isothermal and dynamic heating conditions in a vertical fixed bed type reactor at final temperature of 500, 700 and 900°C under N 2. The solid, liquid, and gas products were in the ranges of 26.94-29.04, 9.43-21.36, 51.70-61.54 wt% for slow pyrolysis, while those attained from rapid condition were 11.16-15.25, 15.00-23.43, and 61.32-73.84 wt%, respectively. Results indicated that char decreased with increasing temperature and hold time. Char with highest fixed carbon of 85.32% with relatively low volatiles of 9.28% was obtained by pyrolysis at 900°C for 60 min. Release of volatile matter led to development of char porous structure. The maximum liquid product of 21.35% was observed at the pyrolysis temperature of 900°C for 60 min under dynamic heating and 61.54% under isothermal heating at 500°C. Decreasing hold time to 15 min caused 2 times decrease of liquid yields. The liquid product mainly consisted of several fatty acids such as oleic acid, palmitic acid and lignoleic acid in the range of 15-19%, 40-45%, and 25-34%, respectively. Increase in temperature and hold time lead to greater production of hydrogen, carbon monoxide, and light hydrocarbons. Mode of heating displayed significant effect to the product distribution, LHV and H 2 /CO ratio. Higher LHV values were obtained at 900°C under rapid pyrolysis condition. Mole ratio of H 2 /CO close to unity was found in the case of pyrolysis at 900°C for both slow and rapid trials. The LHV obtained from slow processes were 7.8-15.0 MJ/Nm 3 while those from rapid runs were 14.8-17.2 MJ/Nm 3 .

Advanced Materials Research, Apr 1, 2012

Pyrolysis is one form of energy recovery process which has the potential to generate oil, gas and... more Pyrolysis is one form of energy recovery process which has the potential to generate oil, gas and char products. The char becomes an attractive by-product, with applications including production of activated carbons, which is useful as a ethylene sorbent for climacteric fruit packaging. In this work, activated carbon prepared from waste tire, produced as a by product of the bio-diesel extraction industry was prepared via chemical treatment with phosphoric acid (H3PO4) at three different char:H3PO4 ratios (1:1, 1:2 and 1:3) under fixed bed pyrolysis at 400, 500 and 600°C for 30 minutes in nitrogen (N2) flow rate of 1000 mL/min and heating rate of 20°C/min. Result shows that char pyrolyzed at 800°C contained high fixed carbon and low volatile content favorable for subsequent activation process compared to other cases.(data not show here) Under the experimental conditions investigated, impregnation ratio of 1:2 were found to be suitable for producing high-surface area activated carbon. It was shown that H3PO4 did work effectively as dehydration reagent at approximately 600°C. The obtained carbons were characterized by nitrogen adsorptiondesorption isotherms at-196 °C. The surface area of activated carbons, which were determined by application of the BrunauerEmmettTeller (BET) and t-plot methods, were achieved as high as 833.50 m2/g. The chemically activated carbons were found to be mainly type II carbons and high adsorption property (Methylene blue adsorption = 622 mg/g and Iodine number = 899 mg/g).

Food Packaging and Shelf Life, 2021

This research aims to prepare foamed hot cups and lids from cellulose fiber (CF)-reinforced biode... more This research aims to prepare foamed hot cups and lids from cellulose fiber (CF)-reinforced biodegradable poly (lactic acid) (PLA) and poly (butylene succinate) (PBS) blend composites for improved strength and thermal resistance. The effects of adding cellulose on physical, chemical, thermal, and mechanical properties of PLA/ PBS/CF were investigated. The composite foams were prepared by twin screw extruder. The results revealed that the viscosity decreased as cellulose fiber was added. All the prepared composites show a shear thinning phenomenon, which is caused by orientation of fibers in the flow direction. A lower content of the CF in the PLA/PBS matrix manifested itself by lower melt viscosity in the whole range of shear rates. The tensile strength, tensile modulus, and percentage of elongation at break increased when the amount of added cellulose fiber increased. The crystallinity of composite foams analyzed by X-Ray Diffraction (XRD) showed higher degree of crystallinity when adding cellulose fiber. The thermal degradation temperature of PLA/PBS/CF composites measured by Thermal Gravimetric Analysis (TGA) showed higher than PLA. The conclusion of this research is that adding cellulose fiber 15 phr improved mechanical and thermal properties.