Reversible Mechanical Regulation and Splicing Ability of Alginate-Based Gel Based on Photo-Responsiveness of Molecular-Level Conformation

In this study, benefiting from the sensitive molecular conformation transversion in azobenzene, a new strategy for fabricating alginate gels with the abilities of splicing and photo-responsive mechanical adjustment is reported. Firstly, a 4,4’-azobis(benzoylhydrazide) (Azo-hydrazide) linker was used to crosslink alginate physically via the electrostatic interaction between hydrazide groups and carboxyl groups. It was then shaped and transferred in situ to a chemically crosslinked gel via 450 nm light irradiation. Under the irradiation, the molecular conformation change of azobenzene in the linker was able to form covalent bonds at the crosslinking points of the gels. Furthermore, the reversible conformation transformation of azobenzene was able to induce the increase and decrease of the storage modulus under irradiation with 365 nm light and 450 nm light, respectively, while also providing gel-like mechanical properties, depending upon the irradiation time and given wavelength. Meanwhile, the results also indicated that active groups could contribute to the splicing ability of the gel and construct a hollow cavity structure. It is believed that this work could provide a versatile strategy for preparing photo-responsive gels with reversibly tunable mechanical properties.

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3D Printing of an In Situ Grown MOF Hydrogel with Tunable Mechanical Properties

ACS Applied Materials & Interfaces ◽

10.1021/acsami.0c08880 ◽

2020 ◽

Vol 12 (29) ◽

pp. 33267-33275 ◽

Cited By ~ 1

Author(s):

Wangqu Liu ◽

Ozan Erol ◽

David H. Gracias

Keyword(s):

Mechanical Properties ◽

3D Printing ◽

Tunable Mechanical Properties

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Bio-inspired fabrication of core@shell structured TATB/polydopamine microparticles via in situ polymerization with tunable mechanical properties

Polymer Testing ◽

10.1016/j.polymertesting.2018.03.046 ◽

2018 ◽

Vol 68 ◽

pp. 126-134 ◽

Cited By ~ 15

Author(s):

Congmei Lin ◽

Feiyan Gong ◽

Zhijian Yang ◽

Liping Pan ◽

Shijun Liu ◽

...

Keyword(s):

Mechanical Properties ◽

In Situ Polymerization ◽

Core Shell ◽

Tunable Mechanical Properties

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Improvement of Mechanical, Hydrophobicity and Thermal Properties of Chinese Fir Wood by Impregnation of Nano Silica Sol

Polymers ◽

10.3390/polym12081632 ◽

2020 ◽

Vol 12 (8) ◽

pp. 1632 ◽

Cited By ~ 3

Author(s):

Enguang Xu ◽

Yanjuan Zhang ◽

Lanying Lin

Keyword(s):

Mechanical Properties ◽

Cell Walls ◽

In Situ Polymerization ◽

Silica Sol ◽

Chinese Fir ◽

Nano Silica ◽

Amorphous Sio2 ◽

Covalent Bonds ◽

Oh Groups

In this paper, a wood-SiO2 composite material was prepared via in-situ polymerization using vacuum/pressure impregnation technology using commercial scale nano silica sol and Chinese Fir (Cunninghamia lanceolate (Lamb.) Hook.). Scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TG), and water contact angle were used to study the changes in the microstructure and physical and mechanical properties of this composite. The results showed that silica sol can penetrate and distribute into the wood cell cavities and surface of cell walls and hence combine with the substances of wood materials. FTIR results indicated that the –OH groups of wood can polycondense in-situ with silica sol to form Si–O–C covalent bonds, and amorphous SiO2 formed from Si–O–Si bonds between the –OH groups of silica sol did not change the crystalline structure of wood cell walls. This in-situ formulating composite significantly improved the compact microstructure, thermal and mechanical properties, and hydrophobicity of the composites.

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Effects of Gamma Irradiation on the Structure and Mechanical Properties of Wild Silkworms and Bombyx Mori Silk Fibroin Films

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.197-198.27 ◽

2011 ◽

Vol 197-198 ◽

pp. 27-31 ◽

Cited By ~ 9

Author(s):

Si Yong Xiong ◽

Ya Mei Xu ◽

Yu Hong Jiao ◽

Lu Wang ◽

Ming Zhong Li

Keyword(s):

Mechanical Properties ◽

Gamma Irradiation ◽

Silk Fibroin ◽

Gamma Ray ◽

Molecular Conformation ◽

Covalent Bonds ◽

Secondary Bonds ◽

Aggregation Structure ◽

Bombyx Mori Silk ◽

Ft Ir

The structure and mechanical properties of A. yamamai, A. perny and B. mori silk fibroin films irradiated by gamma ray with various doses of 0, 25, 50, 100 and 200 kGy, respectively were determined by XRD, FT-IR, DSC and Instron 3365 equipment. Results showed that the aggregation structure and molecular conformation of A. yamamai, A. perny and B. mori silk fibroin films irradiated by gamma ray with those doses mentioned above were not significantly changed. However, with the increase of radiation intensity, the thermal stability of silk fibroin films declined slightly, and the breaking strength and extensibility reduced significantly, due to the breakdown of parts of secondary bonds and covalent bonds. These results suggested that, when these silk fibroin materials were sterilized by gamma irradiation, smaller radiation doses should be used, otherwise irreversible damages on these materials would be caused.

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In situ fabrication of a composite hydrogel with tunable mechanical properties for cartilage tissue engineering

Journal of Materials Chemistry B ◽

10.1039/c8tb01331d ◽

2019 ◽

Vol 7 (15) ◽

pp. 2463-2473 ◽

Cited By ~ 12

Author(s):

Fenbo Ma ◽

Yongmei Ge ◽

Nian Liu ◽

Xiangchao Pang ◽

Xingyu Shen ◽

...

Keyword(s):

Mechanical Properties ◽

Tissue Engineering ◽

Cartilage Tissue Engineering ◽

Composite Hydrogel ◽

Cartilage Tissue ◽

In Situ Fabrication ◽

Tunable Mechanical Properties

A composite hydrogel with tunable mechanical properties has been fabricated and characterized in this study.

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In situ photocrosslinkable hyaluronic acid-based surgical glue with tunable mechanical properties and high adhesive strength

Journal of Polymer Science Part A Polymer Chemistry ◽

10.1002/pola.29290 ◽

2018 ◽

Vol 57 (4) ◽

pp. 522-530 ◽

Cited By ~ 5

Author(s):

Ajeesh Chandrasekharan ◽

Keum-Yong Seong ◽

Sang-Gu Yim ◽

Sodam Kim ◽

Sungbaek Seo ◽

...

Keyword(s):

Mechanical Properties ◽

Hyaluronic Acid ◽

Adhesive Strength ◽

Tunable Mechanical Properties ◽

High Adhesive Strength

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Functionalization of PET with Phosphazene Grafted Graphene Oxide for Synthesis, Flammability, and Mechanism

Materials ◽

10.3390/ma14061470 ◽

2021 ◽

Vol 14 (6) ◽

pp. 1470

Author(s):

Lifei Wei ◽

Rui Wang ◽

Zhiguo Zhu ◽

Wenqing Wang ◽

Hanguang Wu

Keyword(s):

Mechanical Properties ◽

Graphene Oxide ◽

Flame Retardant ◽

In Situ Polymerization ◽

Barrier Effect ◽

Fire Hazards ◽

Peak Heat Release Rate ◽

New Strategy ◽

Tremendous Challenge

Significant improvement in the fire resistance of polyethylene terephthalate (PET) while ensuring its mechanical properties is a tremendous challenge. A novel flame retardant (GO-HCCP, graphene oxide-hexachlorocyclotriphosphazene) was synthesized by nucleophilic substitution of the graphene oxide (GO) and hexachlorocyclotriphosphazene (HCCP) and then applied in PET by an in situ polymerization technique. The scanning electron microscope (SEM) showed a better dispersion of GO-HCCP than GO in the PET matrix. The char yield at 700 °C increased by 32.5% with the addition of GO-HCCP. Moreover, the peak heat release rate (pHRR), peak smoke produce rate (pSPR)and carbon monoxide production (COP)values significantly decreased by 26.0%, 16.7% and 37.5%, respectively, which indicates the outstanding fire and smoke suppression of GO-HCCP. In addition, the composites exhibited higher elastic modulus and tensile strength without compromising the toughness of PET matrix. These significantly reduced fire hazards properties are mainly attributed to the catalytic carbonation of HCCP and the barrier effect of GO. Thus, PET composites with good flame-retardant and mechanical properties were prepared, which provides a new strategy for further flame retardant PET preparation.

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Dynamics of Nanoparticle Chain Aggregates of Carbon Under Tension

MRS Proceedings ◽

10.1557/proc-778-u4.4 ◽

2003 ◽

Vol 778 ◽

Author(s):

Rajdip Bandyopadhyaya ◽

Weizhi Rong ◽

Yong J. Suh ◽

Sheldon K. Friedlander

Keyword(s):

Mechanical Properties ◽

Carbon Black ◽

Polymer Film ◽

Elastic Behavior ◽

Small Strains ◽

Transmission Electron ◽

Chain Aggregates ◽

Nanoparticle Chains ◽

Reinforcing Filler

AbstractCarbon black in the form of nanoparticle chains is used as a reinforcing filler in elastomers. However, the dynamics of the filler particles under tension and their role in the improvement of the mechanical properties of rubber are not well understood. We have studied experimentally the dynamics of isolated nanoparticle chain aggregates (NCAs) of carbon made by laser ablation, and also that of carbon black embedded in a polymer film. In situ studies of stretching and contraction of such chains in the transmission electron microscope (TEM) were conducted under different maximum values of strain. Stretching causes initially folded NCA to reorganize into a straight, taut configuration. Further stretching leads to either plastic deformation and breakage (at 37.4% strain) or to a partial elastic behavior of the chain at small strains (e.g. 2.3% strain). For all cases the chains were very flexible under tension. Similar reorientation and stretching was observed for carbon black chains embedded in a polymer film. Such flexible and elastic nature of NCAs point towards a possible mechanism of reinforcement of rubber by carbon black fillers.

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