Abstract

The hydrogel sponges have prepared successfully from gelatin/chitosan (GEL/CTS) matrix with different polyols basing on scanning electron microscopy (SEM) and Fourier-transform infrared spectroscopy (FTIR) analysis. The results indicate that the compressibility and thermal properties (thermal gravimetric analysis, TGA) were improved significantly with adding the different polyols [poly(vinyl alcohol) – PVA, and poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) – PEPEG] into GEL/CTS matrix. Specially, the as-prepared hydrogel sponges with superabsorbent behavior were also investigated with the attained water absorption capacity to 605 gg⁻¹ and 585 gg⁻¹ for GCV_1/1/0.3 and GCE_1/1/0.3 sponges, respectively, as well as the excellent water absorption capacity in a wide range of pH and salt concentration. Hence, these studies demonstrated that the hydrogel sponges are concerned as potential and promising candidates to apply especially in the fields of biomedicine and hygiene.

Background Introduction:

With the currently technological developments, polymeric material system was widely utilized in various practical applications and research fields. Usually, important factors of a polymeric material are suggested to possible interactions regarding the chemical, physical and interface characterization of a material system. Thus, they are truly needful to undergo relative modification methods to reach better desired properties for various research purposes. As known, hydrogel sponges-based superabsorbent have effective water absorption capacity owing to the hydrophilic functional groups (i.e.: amino/–NH₂, carboxyl/–COOH, and hydroxyl/–OH groups) on the polymer chain. So, the superabsorbent is widely employed in the fields of agriculture, drug delivery, hygiene, purification, and food industry. Additionally, the development and expansion of eco-friendly superabsorbent has been researched and explored intensively to protect environment and ecology. Recently, various natural polymer sources are concerned, in particular, gelatin (GEL) and chitosan (CTS) were widely employed owing to their biocompatibility, biodegradability, antimicrobial activity, non-toxicity, and etc.. However, CTS and GEL alone is not enough strong to favor cell growth, leading to demanding a method of enhancing its mechanical property. Besides, GEL and CTS composites have been also researched and explored for water absorption capacity through chemical modification, while the crosslinking network contained in final products could induce lowing the free available hydrophilic functional groups and create hard polymer chains, as well as it does not favor to improve the water absorption capacity. Hence, in this study, an inexpensive and biodegradable superabsorbent is exploited to form a three-dimensional scaffold – hydrogel sponge. Especially, different polyols [i.e.: poly(vinyl alcohol) – PVA, and poly(ethylene glycol)-poly(propylene glycol)-poly(ethylene glycol) – PEPEG] are employed to combine with GEL/CTS matrix without complex or expensive equipment; moreover, a chemical crosslinking method can be also employed to create the three-dimensional scaffold – hydrogel sponge and to improve its mechanical properties and water absorption capacity. Overall, these polyols are considered to be water-soluble synthetic polymers, mainly due to their availably hydrophilic nature, at same time that the presence of hydrophilic polymers (GEL and these polyols) in a sponge-like material can effectively improve the water absorption capacity in water medium and proper advantages in the fields of biomedicine and hygiene. Especially, glutaraldehyde – an acceptable crosslinker has been used to can bond with several relevant functional groups of above GEL/CTS/polyols mixture to make the hydrogel sponge mechanically strong. The hydrogel sponges are fabricated by a freeze-drying method; concomitantly, the pore size, wall thickness, morphological structures, thermal, compressibility, water absorption capacity (water medium, pH, different salt solutions) of the crosslinked hydrogel sponges are specifically investigated with various volume ratio of GEL/CTS/Polyols to probably elucidate the chemical structural changes and microstructural morphologies in these hydrogel sponges. Thereby, we hope that these hydrogel sponges can become proper materials in the fields of biomedicine and hygiene.

Article Highlights:

• Successfully fabricated crosslinked gelatin/chitosan/polyols (GCV and GCE) sponges using freeze-drying.
• Investigated chemical interactions between polymer chains in hydrogel sponges.
• Achieved optimal pore sizes, wall thickness, and enhanced compressibility.
• Demonstrated effective water absorption capacity in both water and various salt solutions.

Conclusions

The hydrogel sponges with different polyols have prepared successfully basing on the attained SEM, FTIR and TGA results. The mechanical and thermal properties of the hydrogel sponges are improved significantly with adding the polyols into GEL/CTS matrix. Moreover, the hydrogel sponges with superabsorbent behavior have been also investigated, showing that the water absorption capacity can achieve to 605 gg⁻¹ and 585 gg⁻¹ corresponding GCV_1/1/0.3 and GCE_1/1/0.3 sponges. And their water absorption capacity is excellent in a wide range of pH and salt concentration. Therefore, the hydrogel sponges can be considered to be a potential candidate to be applied especially in the fields of biomedicine and hygiene, owing to natural polymer source, non-toxic materials, environmentally friendly candidate, optimal microstructure, excellent water absorption capacity and simple preparation process.

Article Details:

Enhancement of water absorption capacity and compressibility of hydrogel sponges prepared from gelatin/chitosan matrix with different polyols

Thi Sinh Vo, Tran Thi Bich Chau Vo, Trung Tien Tran, Nhan Duy Pham

Article Link:https://doi.org/10.1016/j.pnsc.2021.10.001

Author introduction

Dr. Thi Sinh Vo, I, am a dedicated and accomplished researcher with a strong academic background in Materials Science and Mechanical Engineering. My journey in higher education began at Viet Nam National University Ho Chi Minh City – Ho Chi Minh City University of Science (VNUHCM – HCMUS), where I earned my Bachelor of Science (B.S.) degree in Materials Science in 2014. Eager to deepen my knowledge and expand my expertise, I pursued a Master of Engineering (M.E.) degree in Chemical Engineering from Daegu University, which I completed in 2018. My academic journey reached a significant milestone in 2023 when I was awarded the Ph.D. degree in Mechanical Engineering from Sungkyunkwan University. Throughout my academic career, my primary research interests have been centered around the development and application of polymer and composite materials. My current research focuses on several cutting-edge areas:

Functional Composites and Structures: I investigate the innovative applications of composite materials, aiming to enhance their functionality and performance in various structural applications. This includes exploring new methods for fabricating and optimizing these materials to meet specific engineering requirements.

Electromechanical and Electrochemical Sensors: My work in this area involves the development of sensors that can detect and measure physical or chemical changes in their environment. These sensors have wide-ranging applications, from industrial monitoring to healthcare diagnostics.

Water/Wastewater Treatment: Addressing one of the most critical challenges of our time, I am involved in research aimed at developing advanced materials and technologies for efficient and sustainable water treatment. This includes exploring the use of novel composite materials to improve water purification processes.

I am passionate about leveraging my expertise to solve real-world problems, and I continue to seek opportunities to collaborate with fellow researchers and industry partners to drive innovation and impact in these vital areas of study.