KMITL

Permanent URI for this communityhttps://dspace.kmitl.ac.th/handle/123456789/1

Browse

Search Results

Now showing 1 - 10 of 12

Some of the metrics are blocked by your
consent settings
Porous antimicrobial crosslinked film of hydroxypropyl methylcellulose/carboxymethyl starch incorporating gallic acid for wound dressing application
(2024-01-01)
Pitpisutkul, Vipawan
;
Prachayawarakorn, Jutarat
Because of weak mechanical qualities and low degree of swelling of hydroxypropyl methylcellulose/carboxymethyl starch (HP/CMS) blended films for wound dressing application, this work prepared a unique antimicrobial crosslinked film utilizing succinic acid (SA) as a non-toxic crosslinker and gallic acid (GAL) as an antibacterial agent. It was observed that the infrared-shifted peak position of O[sbnd]H stretching and bending in HP/CMS/SA/GAL films was caused by hydrogen bond formation among HP, CMS and GAL components. The antimicrobial crosslinked films considerably enhanced their mechanical properties and swelling degree. After adding SA and GAL, the films retained their porosity structure as observed by scanning electron images. Moreover, GAL-loaded HP/CMS/SA films could inhibit Staphylococcus aureus and Escherichia coli growth, showing their wound dressing potential. Crystallinity percentage, water vapor transmission rate, gel fraction, water solubility, water uptake and cytotoxicity were also investigated.
Some of the metrics are blocked by your
consent settings
Dynamic changes in cellulose content and biomechanical properties of mycorrhizal roots during growth and decay
(2023-09-01)
Kamchoom, Viroon
;
Chen, Xun Wen
;
Leung, Anthony Kwan
;
Sakolpanya, Tapakorn
;
Srinil, Chortham
Aims: Arbuscular mycorrhizal (AM) fungi have been found to increase plant biomass, cellulose content, and the associated root biomechanical properties, but little is known about how AM fungi affect the in situ root decay process in terms of the changes in the chemical and biomechanical properties. Methods: In this study, we inoculated AM fungi to Bermuda grass (Cynodon dactylon L.) and measured the biomass, the contents of cellulose and lignin, and the biomechanical properties, including tensile strength and Young’s modulus of the grass roots as they grew for 180 days and then decayed for 360 days after burning or for 60 days after the herbicide application. Results: Results show that the AM fungi accelerated the accumulation of grass biomass and root cellulose content compared with non-mycorrhizal grass during the growth period. This effect of AM fungi made mycorrhizal grass generally maintained more biomass and cellulose content than non-mycorrhizal grass at every decaying stage. Inoculation of the AM fungi did not significantly change the root tensile strength or Young’s modulus, but it altered the correlations between tensile strength and root diameter, and Young’s modulus and root diameter. Mycorrhizal effects during the root decaying process appeared to diminish under herbicide treatment, compared with normal growth and burning treatments. Conclusion: Our study highlights the important role of AM fungi in maintaining in situ root biomass (a proxy for carbon content) from decaying or decomposing.
Some of the metrics are blocked by your
consent settings
Production of antimicrobial film-reinforced purified cellulose derived from bamboo shoot shell
(2023-06-01)
Manamoongmongkol, Kanjana
;
Sriprom, Pongsert
;
Phumjan, Lamphung
;
Permana, Lasuardi
;
Assawasaengrat, Pornsawan
In this paper aimed to enhance the mechanical properties of an antimicrobial film by incorporating purified cellulose obtained from bamboo shoot shells into a chitosan matrix. Films with varying amounts of cellulose (0%w/v, 0.2%w/v, and 0.4%w/v) were investigated. Results indicated that the chitosan film reinforced 0.4%w/v cellulose exhibited higher tensile strength (43.50 MPa) and elongation at break (39.40 %) compared to the film without cellulose (34.47 MPa, 18.27 %). Additionally, the film with 0.4%w/v cellulose showed antimicrobial activity against B. cereus (MIC 12.5 mg/mL), S. aureus (MIC 6.25 mg/mL), E. coli (MIC 6.25 mg/mL), and exhibited 68.67 % inhibition of Fusarium oxysporum. Due to its biodegradability, favorable mechanical properties, and strong antimicrobial ability, the cellulose-chitosan film presents a promising alternative to be applied in the food industry, such as in packaging of dried food or as a coating film.
Some of the metrics are blocked by your
consent settings
Hydroxypropyl methylcellulose/carboxymethyl starch/zinc oxide porous nanocomposite films for wound dressing application
(2022-12-15)
Pitpisutkul, Vipawan
;
Prachayawarakorn, Jutarat
Because of low moisture uptake, water vapor transmission rate, oxygen transmission rate, swelling capacity and no antibacterial activity of hydroxypropyl methylcellulose (HPMC) film, carboxymethyl starch (CMS) and zinc oxide nanoparticles (ZnO-NPs) were incorporated in order to improve its limitations for wound dressing application. The infrared shifted peak of O–H stretching and O–H bending in HPMC/CMS blended films was detected due to hydrogen bond formation between HPMC and CMS. Scanning electron images of HPMC/CMS blended films exhibited porous structure. In addition, swelling degree, moisture uptake, water vapor transmission rate and oxygen transmission rate of HPMC/CMS blended films with various contents of CMS clearly increased compared to HPMC film. Moreover, HPMC/CMS nanocomposite films loaded with ZnO-NPs showed good antibacterial activity against Staphylococcus aureus and Escherichia coli, revealing their potential for wound dressing application. Percentage of crystallinity, cytotoxicity, mechanical and thermal properties were also examined.
Some of the metrics are blocked by your
consent settings
Biomechanical properties of the growing and decaying roots of Cynodon dactylon
(2022-02-01)
Kamchoom, Viroon
;
Boldrin, David
;
Leung, Anthony Kwan
;
Sookkrajang, Chanakan
;
Likitlersuang, Suched
Aim: Root growth and decay may affect root reinforcement to soil erosion and stability. We measured the effects of growth and decay on the tensile strength of Cynodon dactylon roots considering different causes of mortality common to agricultural land conversion (i.e. burning and herbicide application). Method: We applied three treatments to C. dactylon grass: (i) growth duration (60, 120 and 180 days), (ii) decay duration after burning (30, 60, 120, 180 and 360 days) and (iii) decay duration after herbicide application (15, 30 and 60 days). The diameter, tensile strength and cellulose and lignin contents of root samples (n = 303) in different treatments were measured. Results: Tensile strength–diameter relations followed a negative power law regardless of treatment (R<sup>2</sup> > 0.6). The increase in median tensile strength values due to grass growth was consistent with the increase in cellulose and lignin contents. Root decay by herbicide application caused significantly greater and faster reduction in tensile strength than burning treatment because of the faster reduction of cellulose and lignin contents. Conclusion: Root decay due to different causes of plant mortality can increase susceptibility to erosion and slope instability during the conversion of agricultural land. Measures on slope safety and erosion are vital when using herbicides for weed clearance in farmlands due to the faster deterioration of root chemical composition and root tensile strength (compared with burning).
Some of the metrics are blocked by your
consent settings
Frequency Domain Spectroscopy of Pressboard Impregnated with Natural Ester under Thermal Stress
(2022-01-01)
Chumpiboon, K.
;
Vittayakorn, W.
;
Kittikhuntharadol, Y.
;
Maneerot, S.
;
Pattanadech, N.
One of the most popular insulating liquids is mineral oil, which is used in many high-voltage apparatuses, especially in transformers. For a few decades, the concept of the use of alternative insulating liquids has been presented. Natural ester is a vegetable-based insulating liquid. Pressboard is a type of electrical insulation paper made of cellulose. Frequency Domain Spectroscopy (FDS) has been used to assess the insulation characteristics such as oil-impregnated paper. In this paper, the FDS of pressboard impregnated with natural ester under thermal stress and pressboard impregnated with natural ester were studied. In the experiment, the pressboard test specimens were heated at 100 degrees Celsius in a vacuum oven for 48 hours to reduce the moisture. Then, the test specimens were impregnated with natural ester for 0, 8, 16, and 24 hours. After that, they were simulated with thermal stress by heating at 150 degrees Celsius in a vacuum oven for 0, 30, and 90 days. To analyze their dielectric integrity, FDS was performed by DIRANA. The test cell for solid insulation testing, according to JIS C2111 was prepared and used for the FDS experiment. The result shows that the characteristics of the natural ester-impregnated pressboard that had been subjected to thermal stress were slightly different when compared with the same impregnation time of the pressboard.
Some of the metrics are blocked by your
consent settings
Influence of cellulose fiber content on morphology and properties of poly(Lactic acid)/propylene-ethylene copolymer/cellulose composites
(2021-01-01)
Wacharawichanant, Sirirat
;
Opasakornwong, Patteera
;
Poohoi, Ratchadakorn
;
Phankokkruad, Manop
This work studied the effects of medium-length fibrous cellulose (MFC) on the morphology, mechanical and thermal properties of poly(lactic acid) (PLA)/propylene-ethylene copolymer (PEC) (90/10) blends. The morphological analysis of PLA/MFC composites observed MFC fibers inserted in the PLA matrix and MFC appeared agglomeration when added high MFC loading. The phase morphology showed the two-phase separation of PLA/PEC blends. The presence of PEC reduced the agglomeration of MFC fibers in polymer matrix. The tensile stress and strain curves found that the ultimate stress of PLA was the highest value and the addition of MFC increased Young’s modulus of PLA/MFC and PLA/PEC/MFC composites. The PEC presence improved the strain at breaking point of PLA/PEC blends. The thermal properties found that the incorporation of MFC did not improve the thermal stability of PLA/MFC and PLA/PEC/MFC composites due to the PLA had degradation temperature higher than MFC.
Some of the metrics are blocked by your
consent settings
Production of Cellulose From Bamboo Shoot Shell Using Hydrothermal Technique
(2021-01-01)
Manamoongmongkol, Kanjana
;
Suwapanich, Rachit
;
Phumjan, Lamphung
;
Narkrugsa, Woatthichai
;
Sriprom, Pongsert
The preparation and characterization of purified cellulose from bamboo shoot shell were studied using fouriertransform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The preparation of cellulose fiber included extraction of cellulose from bamboo shoot shell by treatment with 5 % NaOH and 4 % H2O2, and purification of cellulose fiber using hydrothermal technique. The result showed that cellulose has been successfully extracted at a 32.56% yield by the 5% NaOH / 4% H2O2 treatment, and the purified cellulose was produced using autoclaving at the temperature of 120°C and pressure at 0.1 MPa for 2 h 5 min, with the % recovery of purified cellulose around 94.08. Bamboo shoot shell and cellulose sample were further characterized using FTIR technique. It was found that the 5% NaOH / 4% H2O2 treatment eliminated lignin and hemicellulose from bamboo shoot shell but did not affect cellulose. The hydrothermal technique did not affect the destruction of the cellulose structure as well. Comparison of the SEM image showed that cellulose was separated into individual microfibers after the 5% NaOH / 4% H2O2 treatment while the SEM image of purified cellulose was the small thread-like fibers with smoother surface. Therefore, hydrothermal treatment can be performed for purification of cellulose.
Some of the metrics are blocked by your
consent settings
Optical absorption and FTIR study of cellulose/tio2hybrid composites
(2019-05-01)
Plermjai, Kittiya
;
Boonyarattanakalin, Kanokthip
;
Mekprasart, Wanichaya
;
Phoohinkong, Weerachon
;
Pavasupree, Sorapong
Cellulose/TiO<inf>2</inf> composite was prepared by conventional mixing using distilled water as medium. The structure and relevant properties of cellulose/TiO<inf>2</inf> composite were characterized by X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR) and UV- Vis spectroscopy. XRD results exhibit typical cellulose structure type I. The absorbance spectra of TiO<inf>2</inf>and cellulose exist in vicinity of 200 nm and 350 nm in the UV range, corresponding to the UV-C, UV-B and UV-A. In addition, the UV absorption band of the composite can be extended covering wide UV region. Corresponding FTIR results suggest the existence of chemical bonding or surface interaction between TiO<inf>2</inf> and cellulose.
Some of the metrics are blocked by your
consent settings
Morphology and mechanical properties of poly(Lactic acid) with propylene-ethylene copolymer and α-cellulose
(2019-01-01)
Wacharawichanant, Sirirat
;
Opasakornwong, Patteera
;
Poohoi, Ratchadakorn
;
Phankokkruad, Manop
This work studied the improvement of poly(lactic acid) (PLA) properties by adding propylene-ethylene copolymer (PEC) and α-cellulose (AC). The PLA blends and composites were melt mixed by an internal mixer and molded by compression method. The morphological analysis observed the phase separation of PLA/PEC blends due to minor PEC phase dispersed as spherical shape in PLA phase, indicating a poor interfacial adhesion between PLA and PEC phases. The incorporation of AC did not improve the compatibility of polymer blends. Young’s modulus and tensile strength of PLA blends reduced with increasing amount of PEC because the elastics of ethylene molecules in PEC structure. Young’s modulus of PLA/PEC/AC composites increased with increasing AC contents. The stress at break of the PLA/PEC blends was improved with the presence of AC. The strain at break of PLA/PEC blends increased with increasing PEC contents, and the presence of AC showed the decrease of strain at break of PLA/PEC blends.

KMITL

Browse

Filters

Settings

Sort By

Results per page

Search Results