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Valorization of eggshell waste to metal-doped CaO catalysts for producing dimethyl carbonate by transesterification of propylene carbonate with methanol
(2026-05-01)
Seeharaj, Panpailin
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Werupho, Sakila
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Puyamsai, Araya
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Choengchan, Nathawut
;
Kim-Lohsoontorn, Pattaraporn
To align with a circular economy, this study aimed to extend the lifecycle of eggshell waste by valorizing it into a catalyst for producing the green chemical dimethyl carbonate (DMC) through the transesterification of propylene carbonate (PC) with methanol. CaO derived from eggshells was modified by doping with 10 mol% of aliovalent metal cations, including Na+, Mg2+, and Ce3+, via a calcination-hydration-dehydration process. The catalyst activity was tested under atmospheric air at 40–70 °C for 1–3 h. Metal-doped CaO possessed better activity than pure CaO, and the performance was ranked in order as CaO < Na–CaO < Ce–CaO < Mg–CaO. At the optimized reaction conditions of 50 °C for 2 h, the Mg–CaO catalyst exhibited the best performance, with 77% PC conversion, 62% DMC selectivity, and 37% DMC yield. This improvement correlated with the high surface-active area and optimum basicity induced by incorporating Mg2+ into the CaO structure and forming MgO–CaO mixed oxide phases. This study demonstrated a greener process for producing DMC under mild conditions using metal-doped CaO catalysts derived from eggshell waste.
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Smart Antibacterial Sponge Based on Basil Seed Mucilage/Agar/Mandelic Acid with pH Responsive Feature by Butterfly Pea Extract
(2026-01-01)
Subyai, Natkitta
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Pitpisutkul, Vipawan
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Kruta, Pannita
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Phonrat, Arnon Sai anan
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Prachayawarakorn, Jutarat
The development of antimicrobial wound dressings is critical for enhancing wound healing and preventing infections. This study presented a novel antimicrobial sponge composed of both basil seed mucilage and agar with the addition of mandelic acid as an antibacterial agent, including the incorporation of butterfly pea extract as a pH sensitive substance. The sponges were fabricated through a freeze-drying process, using succinic acid as a crosslinking agent. The functional group analysis offered the infrared-shifted peak position of O-H stretching and O-H bending in basil seed mucilage/agar/succinic acid sponges with the addition of mandelic acid and the extract, indicating of hydrogen bond formation among the crosslinked natural polymers, mandelic acid and the extract. The morphology of the crosslinked sponges incorporated mandelic acid and the extract revealed the opened-cell structures with interconnected cell walls. The crosslinked antibacterial sponges greatly promoted their mechanical properties and gel fraction. The inclusion of mandelic acid did not change the porosity or water retention of the sponges, but the addition of the extract enhanced their swelling behavior. While mandelic acid improved antibacterial activity against both Staphylococcus aureus and Escherichia coli; the extract, provided notable pH-responsive characteristics. The color measurement and cytotoxicity assay were also examined.
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Alternative Polysaccharide Wound Dressing from Heat-Moisture Starch/Basil Seed (O. Basilicum L.) Mucilage with Incorporated Glycolic Acid Antimicrobial Agent
(2025-01-01)
Phonrat, Arnon
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Subyai, Natkitta
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Prachayawarakorn, Jutarat
In order to improve the behavior in water and the mechanical properties of heat-moisture treated starch, natural basil seed mucilage with high hydrophilicity and crystallinity was incorporated for wound dressing application. In addition, succinic acid cross-linking was used to enhance the durability of the material in water and glycolic acid was utilized as an antimicrobial agent. The effectiveness of the cross-linking process could be observed from the significant increase in dimensional stability from higher gel fraction value and increment of mechanical properties. Furthermore, the incorporation of glycolic acid into the wound dressing films demonstrated antibacterial efficacy, resulting in 100% bacterial reduction against S. aureus and E. coli strains. These films exhibited low cytotoxicity toward human epidermal keratinocytes (HaCaT) cells, indicating their potential for biomedical applications. Moreover, functional group analysis, crystallinity, morphology, thermal properties, gel fraction, water vapor transmission rate, free swell absorption, and mechanical properties were also examined.
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Asymmetric dot-patterned wettable and antibacterial wound dressings from bacterial cellulose–alginate composites coated with stearic acid-modified ZnO/chitosan/AgNPs
(2025-01-01)
Ieamviteevanich, Pimchanok
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Onklam, Panida
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Kampechdee, Wariya
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Churiwan, Achana
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Vittayakorn, Naratip
To improve the wound dressing characteristics of bacterial cellulose-based materials and address the issue of asymmetric wound dressing with one hydrophilic side and another hydrophobic side, this study developed a new concept for the fabrication of an asymmetric wettable and antibacterial wound dressing by selective drop coating of stearic acid-modified ZnO, chitosan, and AgNPs to form a dot pattern on both surfaces of a bacterial cellulose–alginate composite (BA-ZnS/Ch/Ag). The coated surface was hydrophobic, with a WCA of 150° due to the formation of a low surface energy zinc stearate (C<inf>17</inf>H<inf>35</inf>COO)<inf>2</inf>Zn) monolayer on the ZnO particles and a high degree of hierarchical roughness. The asymmetric wettable BA-ZnS/Ch/Ag wound dressing maintained good water absorptivity (swelling rate 417%) and natural breathability (water vapor transmission rate 792 g.m−2 day−1) of the superhydrophilic bacterial cellulose-alginate composite that consisted of dense outer surfaces and porous inner layers and simultaneously possessed the superhydrophobic property of the coating area that can reduce the risk of infection from external fluids and improve the blood repellency and anti-adhesion properties. The BA-ZnS/Ch/Ag wound dressing showed good antibacterial activity against S. aureus and E. coli and non-toxicity to human keratinocyte immortal cells (HaCaT), making it suitable for clinical applications.
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Porous antimicrobial crosslinked film of hydroxypropyl methylcellulose/carboxymethyl starch incorporating gallic acid for wound dressing application
(2024-01-01)
Pitpisutkul, Vipawan
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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.
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Natural wound dressing films prepared from acetylated starch/κ-carrageenan blend incorporated with mandelic acid
(2024-01-01)
Sriphochai, Wimolsiri
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Prachayawarakorn, Jutarat
Due to several limitations of acetylated starch film for wound dressing applications such as low mechanical properties and no antibacterial activity, acetylated starch film was, therefore, modified by different contents of κ-carrageenan and mandelic acid. Infrared spectra confirmed the presence of κ-carrageenan and mandelic acid in the modified acetylated starch films. In addition, the decreased crystallinity of the carrageenan modified acetylated starch films led to more smooth film, as observed by scanning electron images. Besides, the addition of various amounts of κ-carrageenan in the modified acetylated starch films caused the improvement of mechanical properties, moisture uptake, water vapor transmission rate (WVTR), and degree of swelling. Moreover, κ-carrageenan modified acetylated starch film loaded with 20 wt% of mandelic acid exhibited antibacterial property against both S.aureus and E.coli bacteria. Additionally, degree of crystallinity, mechanical properties, moisture uptake, WVTR, degree of swelling, antibacterial activity, and cytotoxicity of κ-carrageenan modified acetylated starch films added by different amounts of mandelic acid were also studied.
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Modification of biodegradable thermoplastic cassava starch/kapok fiber incorporated by tartaric acid and processed by compression molding technique
(2024-01-01)
Panjapornpattana, Kanisara
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Sareethao, Supapich
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Prachayawarakorn, Jutarat
Thermoplastic starch has been attracted due to its availability, biodegradability, and processability. However, its poor tensile properties, high hydrophilicity and lack of antibacterial activity are still the major concerns for many applications. In current study, several thermoplastic cassava starch samples (THPCS), reinforced with kapok (KP) fibers and modified by varying levels of tartaric acid (TA), a natural organic acid, were prepared to enhance their limitations. All samples were mixed and shaped using an internal mixer and a compression molding machine, respectively. The modified THPCS samples were characterized using analytical techniques such as FTIR, SEM and TGA. Morphology, water uptake, mechanical properties, biodegradability, and antimicrobial performance of various samples were also evaluated. IR peak positions of O–H stretching as well as O–H bending were clearly observed for shifting to lower wavenumbers with the addition of KP fibers or KP fibers/TA, indicating of new H-bond formation. In addition, the use of KP fibers caused the enhancement of mechanical strength and thermal properties including the reduction of water uptake. Moreover, THPCS/KP fiber sample modified by TA presented surface smoothness, good biodegradability, and antibacterial performance against both Staphylococcus aureus and Escherichia coli.
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Natural wound dressing from acid-modified basil seed mucilage containing aloe vera extract
(2024-01-01)
Seeharaj, Panpailin
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Siriwat, Piyapol
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Phonrat, Arnon
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Prachayawarakorn, Jutarat
There have been several studies that have applied basil)Ocimum basilicum L.(seed mucilage)BSM(as a wound dressing materials using several types of synthetic antimicrobial agents. This research reports on the application of BSM as a green wound dressing using natural substance, namely aloe vera (AV) extract for the improvement of antibacterial activity. Due to poor dimensional stability of BSM, malonic acid (MA) was used to crosslink the BSM molecules. The MA resulted in the esterification reaction between BSM molecules, as revealed by FTIR peak position of the C=O stretching. The porosity, water retention and swelling of BSM sponges were noted to decrease, while stiffness increased upon crosslinking. Incorporation of AV extract into both BSM and MA-crosslinked BSM sponges did not affect hydrophilicity, mechanical properties, thermal properties and cytotoxicity toward HaCaT cells. On the other hand, antibacterial activities against both Gram-positive bacteria)Staphylococcus aureus(and Gram-negative bacteria)Pseudomonas aeruginosa(of BSM and BSM crosslinked by MA were observed upon the addition of the AV extract.
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Effects of Hydroxypropyl Methylcellulose Fiber Amounts and Aspect Ratios on Properties of Biodegradable Composites Prepared from Thermoplastic Starch
(2023-01-01)
Pitpisutkul, Vipawan
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Jamjumras, Trisana
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Sawasdee, Kancharut
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Prachayawarakorn, Jutarat
Because of the low tensile properties and high hydrophilicity of thermoplastic starch (TPS), this research was focused on improving its characteristics through the addition of the natural cellulose fiber, hydroxypropyl methylcellulose (HPMC). Different TPS composites reinforced with HPMC fibers were compounded using an internal mixer and were shaped using a compression molding machine. The effects of HPMC fiber content and aspect ratios were examined. It was found from infrared spectra that the wavenumbers of the O-H stretching of TPS polymer clearly shifted to lower wavenumber with the incorporation of HPMC fibers, which indicated new hydrogen bond formation. Moreover, a significant increase of maximum stress and elastic modulus of TPS/ HPMC fiber composites was detected. A clear drop in moisture uptake was also found when HPMC fibers were added into the TPS polymer matrix. In addition, scanning electron microscopy and thermogravimetric analysis were used to characterize several TPS composites. Biodegradability for various composites was also determined.
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Hydroxypropyl methylcellulose/carboxymethyl starch/zinc oxide porous nanocomposite films for wound dressing application
(2022-12-15)
Pitpisutkul, Vipawan
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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.

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