Photocatalytic Microporous Polymer-Hydrogel Composites for the Removal of a Dye in Water

김도연,장지영 한국고분자학회 2020 Macromolecular Research Vol.28 No.13

Photocatalytic hydrogel composites were prepared by using multifunctional microporous polymer particles as a reinforcing agent and also as a catalytic species. A benzothiadiazole-based conjugated microporous polymer (BTCMP) was synthesized by the Sonogashira-Hagihara reaction between 4,7-dibromo-2,1,3-benzothiadiazole and 1,3,5-triethynylbenzene as insoluble particles. BTCMP particles were functionalized with acryl groups via the thiol-yne click reaction with 2-aminoethanethiol and subsequent reaction with acryloyl chloride. Acrylated BTCMP particles were polymerized with acrylamide in a glass mold to yield a highly elastic hydrogel composite sheet. The tensile test results showed that covalently incorporated BTCMP particles significantly enhanced the mechanical properties of the hydrogels compared with a pure polyacrylamide hydrogel. A possible application of the hydrogel composites for the removal of a dye in water was studied using methylene blue as an exemplary dye. The maximum methylene blue adsorption capacity of the hydrogel composite containing 2 wt% of BTCMP particles was 2.6 times higher than that of the pure polyacrylamide hydrogel. The hydrogel composite with photocatalytic activity originated from benzothiadiazole groups degraded adsorbed methylene blue molecules in an aqueous solution upon UV irradiation. The hydrogel composite could be reused for the methylene blue removal without any significant decrease in adsorption capacity and catalytic activity.

Graphene oxide composite hydrogels for wearable devices

Tang Senxuan,Liu Zhihan,Xiang Xu 한국탄소학회 2022 Carbon Letters Vol.32 No.6

For graphene oxide (GO) composite hydrogels, a two-dimensional GO material is introduced into them, whose special structure is used to improve their properties. GO contains abundant oxygen-containing functional groups, which can improve the mechanical properties of hydrogels and support the application needs. Especially, the unique-conjugated structure of GO can endow or enhance the stimulation response of hydrogels. Therefore, GO composite hydrogels have a great potential in the field of wearable devices. We referred to the works published in recent years, and reviewed from these aspects: (a) structure of GO; (b) factors affecting the mechanical properties of the composite hydrogel, including hydrogen bond, ionic bond, coordination bond and physical crosslinking; (c) stimuli and signals; (d) challenges. Finally, we summarized the research progress of GO composite hydrogels in the field of wearable devices, and put forward some prospects.

A New Method of Gelatin Modified Collagen and Viscoelastic Study of Gelatin-Collagen Composite Hydrogel

Lang He,Sheng Li,Chengzhi Xu,Benmei Wei,Juntao Zhang,Yuling Xu,Beirong Zhu,Yang Cao,Xilin Wu,Zhijin Xiong,Rongrui Huang,Jian Yang,Haibo Wang 한국고분자학회 2020 Macromolecular Research Vol.28 No.9

Pure collagen materials are expensive with poor mechanical properties, which need modifications in most cases. As the degradation product of collagen, gelatin is cheap, degradable and biocompatible, but few literatures have reported the research about gelatin-collagen composite materials. This is because gelatin and collagen have different soluble temperatures—gelatin is soluble in hot water (≥30 oC) and swells in cold water. However, a low temperature (2-10 oC) is required to prepare and store collagen solution, and neutral collagen solution denatures quickly above the room temperature. In this study, gelatin was ground into powders and swelled in neutral bovine tendon pepsin-soluble collagen solution (BPSC) to form a homogeneous gelatin-collagen mixture, in light of the swelling characteristics of gelatin in cold water. The assembly properties and gel properties of this composite material were further studied. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) test results showed that the bovine tendon collagen had typical type-I collagen structural characterizations with two α chains of about 100 kDa and one β chain of about 200 kDa; while the SDS-PAGE pattern of gelatin displayed bands continuously distributed from 30 to 200 kDa. Amino acid composition analysis test indicated that the content of polar amino acids and the sum of acidic and base amino acids for gelatin were higher than that of BPSC. Studies on gel properties demonstrated that gelatin-collagen mixed solution had collagenlike assembly characteristics and assembly kinetics. The moduli of the assembled gel at 35 oC were equivalent to that of pure bovine tendon collagen system; moreover, the system moduli didn’t change with time with elastic moduli (G') of about 40 Pa. However, at 25 oC, the moduli of gelatin-collagen composite hydrogel increased with the extension of time, its G' increased about 18 times within 8 h, and the ratio of elastic modulus to viscous modulus (G'') increased 4.6 times, showing a significant aging effect of structural strength. Meanwhile, the mechanical strength of the composite hydrogel was also regulated by temperature—the gel was highly elastic (G'≈3,000 Pa, G'>>G'') at a low temperature (5 oC); as the temperature rose, the system moduli gradually decreased and the elastic gel transformed into waterlike fluid at 50 oC little by little. What’s more, gelatin-collagen composite hydrogel also had reversible sol-gel performances and self-healing capability similar to the gelatin hydrogel. This novel preparation method for preparing composite materials and the resultant composite hydrogel are expected to be used in the fields of natural food gels, injectable hydrogels, cell scaffolds, drug sustained-release materials and so on, and improve and promote the processing performances, price and large-scale production of collagen-based materials.

Long-lasting and bioactive hyaluronic acid-hydroxyapatite composite hydrogels for injectable dermal fillers: Physical properties and in vivo durability

Jeong, Seol-Ha,Fan, Ying-Fang,Baek, Jae-Uk,Song, Juha,Choi, Tae-Hyun,Kim, Suk-Wha,Kim, Hyoun-Ee SAGE Publications 2016 Journal of biomaterials applications Vol.31 No.3

<P>Hyaluronic acid (HAc)-hydroxyapatite (HAp) composite hydrogels were developed to improve the biostability and bioactivity of HAc for dermal filler applications. Two kinds of HAc-HAp composite fillers were generated: HAcmicroHAp and HAc-nanoHAp composites. HAc-microHAp was fabricated by mixing HAp microspheres with HAc hydrogels, and HAc-nanoHAp was made by in situ precipitation of nano-sized HAp particles in HAc hydrogels. Emphasis was placed on the effect of HAp on the durability and bioactivity of the fillers. Compared with the pure HAc filler, all of the HAc-HAp composite fillers exhibited significant improvements in volumetric maintenance based on in vivo tests owing to their reduced water content and higher degree of biointegration between the filler and surrounding tissues. HAc-HAp composite fillers also showed noticeable enhancement in dermis recovery, promoting collagen and elastic fiber formation. Based on their long-lasting durability and bioactivity, HAc-HAp composite fillers have great potential for soft tissue augmentation with multifunctionality.</P>

Porous hydrogel containing Prussian blue nanoparticles for effective cesium ion adsorption in aqueous media

Kim, Youngjin,Kim, Inhye,Lee, Taek Seung,Lee, Eunji,Lee, Kyung Jin Elsevier 2018 Journal of industrial and engineering chemistry Vol.60 No.-

<P><B>Abstract</B></P> <P>Cesium adsorbent was fabricated by synthesizing Prussian blue (PB) via redox reaction between K<SUB>3</SUB>[Fe(CN)<SUB>6</SUB>] and FeCl<SUB>3</SUB> in inverse-high-internal-phase-emulsion (i-HIPE) hydrogel. The PB nanoparticles are successfully generated via novel pathway, in-situ redox reaction in hydrogel. Maximum cesium ion uptake capacity of composite is 0.1047mmol/g (per composite amount) which is 3-times higher than that of purchased PB, even though very small amount of PB have been inserted. Adsorption kinetics and isotherm of PB/i-HIPE hydrogel was followed to pseudo-first-order and Langmuir model respectively. These results can provide excellent pathway to design effective absorbent for removal of radio-active, aqueous cesium ion in environments.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Prussian blue nanoparticles were synthesized by a redox reaction in the porous hydrogel. </LI> <LI> PB nanoparticles were dispersed homogeneously in i-HIPE hydrogel. </LI> <LI> Fabricated adsorbent followed pseudo-first-order kinetics and Langmuir isotherm. </LI> <LI> Hydrogel-based adsorbent has efficient cesium uptake abilities in many conditions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Prussian blue nanoparticles were synthesized in the porous hydrogel by a redox reaction for effective adsorption of Cs ion in aqueous condition. The results of cesium uptake test showed that PB-containing i-HIPE hydrogel has higher and efficient cesium uptake ability compared to previous works owing to homogeneous and well-dispersion of PB particle in porous hydrogel.</P> <P>[DISPLAY OMISSION]</P>

Tough Bioactive Composite Hydrogel of Gelatin Methacrylate and Bacterial Cellulose Prepared by Combined Freeze-Thaw and Photocrosslinking Processes

Yeji Han,Jinho Hyun 한국펄프·종이공학회 2024 펄프.종이기술 Vol.56 No.4

Despite the excellent structural stability and mechanical properties of bacterial cellulose (BC) hydrogels, BC hydrogels do not have sufficient bioactivity to support the growth and proliferation of tissue cells. Gelatin methacrylate (GelMA) is a good choice to compensate for the bioactivity of BC hydrogel. However, GelMA itself does not provide sufficient mechanical properties for the structure, and it is also difficult to use as an ink for printing at low concentrations. The increase in GelMA concentration can enhance its mechanical properties, but the biocompatibility decreases due to the increased hydrogel density. Here, we prepared a tough and biocompatible composite hydrogel using BC incorporated with GelMA. A freeze-thaw process was introduced in the fabrication of the BC/GelMA composite hydrogel to improve its mechanical properties. The GelMA interpenetrated in the BC structure was freezethawed and photo-crosslinked to enhance mechanical properties. Such a process provided double networks within the highly networked structure of BC. Moreover, the order of freeze-thaw and photo-crosslinking created a significantly different reinforcing effect with the BC/GelMA composite hydrogel.

Effects of precursor composition and mode of crosslinking on mechanical properties of graphene oxide reinforced composite hydrogels

Jang, Jinhyeong,Hong, Jisu,Cha, Chaenyung Elsevier 2017 Journal of the mechanical behavior of biomedical m Vol.69 No.-

<P><B>Abstract</B></P> <P>Graphene oxide (GO) is increasingly investigated as a reinforcing nanofiller for various hydrogels for biomedical applications for its superior mechanical strength. However, the reinforcing mechanism of GO in different hydrogel conditions has not been extensively explored and elucidated to date. Herein, we systematically examine the effects of various types of precursor molecules (monomers vs. macromers) as well as mode of GO incorporation (physical vs. covalent) on the mechanical properties of resulting composite hydrogels. Two hydrogel types, (1) polyacrylamide hydrogels with varying concentrations of acrylamide monomers and (2) poly(ethylene glycol) (PEG) hydrogels with varying molecular weights of PEG macromers, are used as model systems. In addition, incorporation of GO is also controlled by using either unmodified GO or methacrylic GO (MGO) which allows for covalent incorporation. The results in this study demonstrate that the interaction between GO and the surrounding network and its effect on the mechanical properties (i.e. rigidity and toughness) of composite hydrogels are highly dependent on both the type and concentration of precursors and the mode of crosslinking. We expect this study will provide an important guideline for future research efforts on controlling the mechanical properties of GO-based composite hydrogels.</P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Anisotropic mechanical responses of composites having water microchannels

Cho, Yunho,Lee, Jonghwi THE KOREAN SOCIETY OF INDUSTRIAL AND ENGINEERING 2018 JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY -S Vol.60 No.-

<P><B>Abstract</B></P> <P>The combination of extremely different materials could result in composites with unique properties, although their different properties make the combination challenging. If water-swellable phases are combined with water-insoluble rubbery phases, the resulting composites can act as water-swellable and mechanically durable rubbers. Herein, novel composites of hydrophilic poly(<I>N</I>-isopropylacrylamide) (PNIPAM) or poly(ethylene glycol) and hydrophobic polyurethane (PU) or poly(dimethylsiloxane) were prepared by directional melt crystallization and a subsequent infiltration process. When the composites were compressed parallel to their microchannel direction, much higher moduli were obtained, and their unique deflection and plateau regions existed due to irreversible deformations such as buckling. The moduli of water-swollen PU/PNIPAM were higher than those of porous PU. The hysteresis of cyclic compression was maximal in the cases of parallel compression with a low swelling ratio (SR), which could effectively absorb mechanical energy input. On the other hand, perpendicular compression with a high SR produced reversible mechanical behavior. These results demonstrate that the pore-filling properties of hydrogels by swelling enhance the mechanical properties of composites. We also found that the deswelling kinetics of composites were surprisingly fast. These unique properties of water-swellable composites could be advantageous for various applications in future industries.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The mechanical properties of novel composites having two separate and distinct phases were studies. </LI> <LI> The two phases, a water-swellable and a hydrophobic rubber phases, were combined into 3D co-continuous composites. </LI> <LI> Surprisingly fast deswelling kinetics and unique anisotropic mechanical responses were found. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Novel composites having two separate and distinct phases of extremely different properties showed surprisingly fast deswelling kinetics and unique anisotropic mechanical responses.</P> <P>[DISPLAY OMISSION]</P>

Mechanical and Cell-Adhesive Properties of Gelatin/Polyvinyl Alcohol Hydrogels and Their Application in Wound Dressing

정희석,이득용,양대혁,송요승 한국고분자학회 2022 Macromolecular Research Vol.30 No.4

Gelatin/polyvinyl alcohol (PVA) (g/P) porous hydrogels are chemically and physically crosslinked to evaluate the influence of the g/P weight ratio on the mechanical properties and cell adhesion behavior of the composite hydrogels. The degradation rate, pore size, and swelling rate of the g/P hydrogels decreased when the g/P ratio was lowered from 10/0 to 0/10 owing to the presence of PVA. Although the compressive strength increased with the increase in the PVA proportion in g/P hydrogels, no cell adhesion was observed in pure PVA due to the absence of ligands that bind to cell-surface receptors. Hydrogels with properties tailored for wound dressings can be obtained by adjusting the specific proportions of gelatin and PVA. We conclude that 5/5 and 7/3 g/P hydrogels can be applied as wound healing biomaterials because of their suitable mechanical properties, and their ability to facilitate rapid cell adhesion and proliferation.

A systematic method of synthesizing composite superabsorbent hydrogels from crosslink copolymer for removal of textile dyes from water

Ruma Bhattacharyya,Samit Kumar Ray,Bidyadhar Mandal 한국공업화학회 2013 Journal of Industrial and Engineering Chemistry Vol.19 No.4

A systematic method was employed to synthesize several hydrogels by crosslink copolymerization of acrylamide (AM), hydroxyl ethylmethacrylate (HEMA) and N,N’-methylenebisacrylamide (NMBA) at varied operating conditions. Composite hydrogels were also prepared by in situ incorporation of varied amounts of sodium aluminosilicate filler to the monomer mixtures at optimum operating conditions. These hydrogels were used for removal of rhodamine B and methyl violet dye from water at low (0.5–3 mg/L) and high concentration (50–500 mg/L) ranges. The composite hydrogels showed much higher dye adsorption than the unfilled hydrogels. Kinetic, adsorption and thermodynamic parameters for dye adsorption were also evaluated.