Facile and green fabrication of silk sericin films reinforced with bamboo-derived cellulose nanofibrils

Kwak, Hyo Won,Lee, Hohyun,Lee, Min Eui,Jin, Hyoung-Joon Elsevier 2018 Journal of cleaner production Vol.200 No.-

<P><B>Abstract</B></P> <P>As the interest in the recycling of byproducts and resources derived from agriculture has increased, research on the application of sericin abandoned in the silk industry has been continuously carried out, but there is a limit due to the weak mechanical properties. Recently, nanocellulose has been attracting attention as an optimal reinforcing material to improve the deficient physical properties of natural polymers. In the present study, bamboo-derived cellulose nanofibrils (B-CNFs) were prepared and used as a facile reinforcer to improve the mechanical properties of the sericin film. B-CNF was prepared <I>via</I> simple and eco-friendly ultrasonic treatment and whole bio-nanocomposite film fabrication process conducted under aqueous solution condition. The prepared B-CNF was well distributed into the glycerol-plasticized sericin matrix without agglomeration until 10 wt% B-CNF loading, while agglomerated cellulose nanofibrils appeared after 20 wt% B-CNF loading. This uniform distribution of B-CNF not only greatly improved the properties of the sericin film but also affected the hydrophilic properties of bio-nanocomposite film. Moreover, the prepared B-CNF reinforced bio-nanocomposite films had notable antioxidant activity without any additional antioxidant ingredients. These findings support the potential use of B-CNF reinforced sericin films in active food packaging, drug delivery carriers, and in wound dressing materials. Silk and bamboo-derived natural polymeric raw materials and aqueous solvent-based film manufacturing processes will strongly provide cost efficiency and environmental friendliness and can be a suitable replacement of petroleum-based polymer industry and its related application fields.</P> <P><B>Highlights</B></P> <P> <UL> <LI> “Green” nanocomposite films were prepared using sericin/cellulose nanofibril. </LI> <LI> Cellulose nanofibrils were prepared by an eco-friendly ultrasonication process. </LI> <LI> The tensile properties nanocomposites were enhanced compared to the raw sericin. </LI> <LI> The hydrophilic properties were easily tunable via nanofibril amount control. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Development of Multifunctional Gelatin Materials Based on Green Chemistry

Hyo Won Kwak(곽효원) 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1

Gelatin has been widely used in food, medicine, and cosmetics fields due to its excellent biocompatibility and biodegradability. However, in recent years, due to infectious disease problems and religious restrictions due to the use of mammalian gelatin, research on high value-added through the discovery of eco-friendly gelatin raw materials and the development of functional materials using the same has been actively conducted. This study introduces the processing of various formulations of functional gelatin materials such as nano-microfibers, films, and adhesive solutions using fish-derived gelatin as a next-generation gelatin raw material. In addition, an eco-friendly crosslinking strategy to improve the physicochemical properties of gelatin materials will be introduced. In addition, multidimensional gelatin materials with various functionality such as biocompatibility, antibacterial and antioxidant properties, UV blocking ability will be introduced.

Monitoring of phase separation between silk fibroin and sericin using various dye system

( Hyo Won Kwak ),( Ki Hoon Lee ) 한국잠사학회 2015 International Journal of Industrial Entomology Vol.30 No.1

Understanding the interactions between fibroin and sericin is crucial in solving the mechanism of silk spinning. In this study, various commercially available dyes were used to monitor the interface between fibroin and sericin during the gelation of fibroin. The phase separation between fibroin and sericin could be observed by the addition of azo dyes over a certain molecular weight. Furthermore, the addition of the dyes to the sericin layer showed vivid phase separation over addition to the fibroin layer.

Prevention of cellulose nanofibril agglomeration during dehydration and enhancement of redispersibility by hydrophilic gelatin

Kwak, Hyo Won,You, Jinhwa,Lee, Min Eui,Jin, Hyoung-Joon Springer-Verlag 2019 CELLULOSE Vol.26 No.7

Preparation of Silk Sericin/Lignin Blend Beads for the Removal of Hexavalent Chromium Ions

Kwak, Hyo Won,Shin, Munju,Yun, Haesung,Lee, Ki Hoon MDPI 2016 INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES Vol.17 No.9

<P>In the present study, novel adsorbents having high adsorption capability and reusability were prepared using agricultural by-products: silk sericin and lignin. Silk sericin and lignin blend beads were successfully prepared using simple coagulation methods for the removal of hexavalent chromium (Cr(VI)) from aqueous solution. A 1 M lithium chloride (LiCl)/dimethyl sulfoxide (DMSO) solvent system successfully dissolved both sericin and lignin and had sufficient viscosity for bead preparation. Compared to the conventional sericin bead adsorbent, sericin/lignin blend beads showed higher Cr(VI) adsorption capacity. The amount of lignin added to the adsorbent greatly affected the adsorption capacity of the beads, and a 50:50 sericin/lignin blend ratio was optimal. Adsorption behavior followed the Freundlich isotherm, which means the adsorption of Cr(VI) occurred on the heterogeneous surface. Cr(VI) adsorption capability increased with temperature because of thermodynamic-kinetic effects. In addition, over 90% of Cr(VI) ions were recovered from the Cr(VI) adsorbed sericin/lignin beads in a 1 M NaOH solution. The adsorption-desorption recycling process was stable for more than seven cycles, and the recycling efficiency was 82%. It is expected that the sericin/lignin beads could be successfully applied in wastewater remediation especially for hazardous Cr(VI) ions in industrial wastewater.</P>

Strategies for Manufacturing Eco-friendly Lignocellulosic Biosorbent and Improving Their Heavy Metal Removal Capacity

Hyo Won Kwak(곽효원) 한국고분자학회 2020 한국고분자학회 학술대회 연구논문 초록집 Vol.45 No.2

Entomopathogenic fungal infection of Allomyrina dichotoma in mass breeding conditions

Kwak, Kyu-Won,Nam, Sung-Hee,Choi, Hyo-Won,Choi, Ji-Young,Lee, Seok-Hyun,Kim, Hong-Geun,Han, Myung-Sae,Park, Kwan-Ho Korean Society of Sericultural Science 2015 International Journal of Industrial Entomology Vol.31 No.1

Increased use of rhinoceros beetles (Allomyrina dichotoma ) for food and medicine, and their elevated value as pets has led to an increase in the number of their breeding farms. Mass breeding of the insects in these farms leads to entomological diseases. In this study, we investigate cannibalism resulting from overcrowded breeding of A. dichotoma larvae, as well as secondary fungal infections in epidermal wounds in the surviving larvae. Some of the fungi detected in the present study showed entomopathogenicity, and the larvae showed different times of death. In particular, larvae infected with Clonostachys sp., an endophytic plant fungus, grew for a long time after infection, but died without pupating.

High-toughness natural polymer nonwoven preforms inspired by silkworm cocoon structure

Kwak, Hyo Won,Eom, Jungju,Cho, Se Youn,Lee, Min Eui,Jin, Hyoung-Joon Elsevier 2019 INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES Vol.127 No.-

<P><B>Abstract</B></P> <P>As the interest in environmentally friendly materials and concerns regarding depletion of petroleum resources has increased, the research on natural polymers is being actively pursued. Among the various materials based on natural polymeric resources, the interest in using natural fibers in bio-composites has grown due to their lightweight, non-toxicity, low cost, and abundance. However, the lack of interfacial adhesion between filaments and poor water resistance make the use of natural fiber-based polymer composites less attractive. To overcome these drawbacks, formaldehyde-based synthetic binders have been used. However, this requires an additional synthesis of the binder, and potential toxicity problems exist. In this work, robust and rigid natural polymer nonwoven preforms were prepared by mixing jute fibers with silk sericin (SS). SS was employed as a natural facile binder and the strong binding between jute fibers and SS resulted in remarkable enhancements in tensile strength, elongation, and toughness, which increased up to 539.1, 385.7, and 1943.8%, respectively, compared with the pristine jute nonwoven. In addition, the dense and rigid structure obtained through SS coating ensured the structural stability of the nonwoven preforms in moisture environments. Silkworm cocoon-structured natural polymer nonwoven preforms with excellent mechanical strength and higher physical stability may have more potential utilization in the composite material fields.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Silkworm cocoon-like natural fiber-based nonwoven preforms were fabricated. </LI> <LI> Sericin strongly bonded interface between each jute filament. </LI> <LI> Sericin dramatically improves the mechanical properties of jute nonwoven preforms. </LI> <LI> The water resistance of nonwoven preforms was obtained by sericin binder. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Chromium(VI) Adsorption Behavior of Silk Sericin Beads

Kwak, Hyo Won,Yang, Ye Sol,Kim, Moo Kon,Lee, Jeong Yun,Yun, Haesung,Kim, Min Hwa,Lee, Ki Hoon Korean Society of Sericultural Science 2013 International Journal of Industrial Entomology Vol.26 No.1

Silk sericin (SS) has been fabricated into beads using a 1 M LiCl/DMSO solvent and utilized as a heavy metal adsorbent. Among the various heavy metals, we targeted Cr(VI) for adsorption using SS beads and found that its adsorption depended on the coagulant used for the fabrication of the SS beads. When methanol was used as a coagulant, the beads had a better adsorption capacity than when ethanol was used except at pH 1. The adsorption behavior of Cr(VI) on the SS beads followed the BET isotherm. The maximum adsorption capacity was 33.76 mg/g at pH 2. The adsorption of Cr(VI) was confirmed by FT-IR and EDS analyses. Finally, the desorption was carried out using NaOH solution, and it was found that 73.19% of the adsorbed Cr(VI) could be detached.

Monitoring of phase separation between silk fibroin and sericin using various dye system

Kwak, Hyo Won,Lee, Ki Hoon Korean Society of Sericultural Science 2015 International Journal of Industrial Entomology Vol.30 No.1

Understanding the interactions between fibroin and sericin is crucial in solving the mechanism of silk spinning. In this study, various commercially available dyes were used to monitor the interface between fibroin and sericin during the gelation of fibroin. The phase separation between fibroin and sericin could be observed by the addition of azo dyes over a certain molecular weight. Furthermore, the addition of the dyes to the sericin layer showed vivid phase separation over addition to the fibroin layer.