Self-healing And Mechanochromic Polymers With Dynamic Carbon–Carbon Covalent Bonds

2018 ◽  
Author(s):  
Hideyuki Otsuka
Keyword(s):  
Self Healing ◽  
Covalent Bonds

Imine Based Self-Healing Hydrogel Triggered by Periodate

2020 ◽  
Author(s):  
Alexis Wolfel ◽  
Cecilia Inés Alvarez Igarzabal ◽  
Marcelo Ricardo Romero
Keyword(s):  
Functional Groups ◽  
Time Window ◽  
Crosslinking Reaction ◽  
Self Healing ◽  
Swelling Properties ◽  
Covalent Bonds ◽  
Smart Systems ◽  
Primary Amino ◽  
Vicinal Diols ◽  
Aldehyde Groups

<p>Design of materials with novel sensitivities and smart behaviour is important for the development of smart systems with automated responsiveness. We have recently reported the synthesis of hydrogels, cross-linked by <i>N,N'</i>-diallyltartardiamide (DAT). The covalent DAT-crosslinking points have vicinal diols which can be easily cleaved with periodate, generating valuable a-oxo-aldehyde functional groups, useful for further chemical modification. Based on those findings, we envisioned that a self-healable hydrogel could be obtained by incorporation of primary amino functional groups, from <a>2-aminoethyl methacrylate </a>hydrochloride (AEMA), coexisting with DAT into the same network. The a-oxo-aldehyde groups generated after the reaction with periodate would arise in the immediate environment of amine groups to form imine cross-links. For this purpose, DAT-crosslinked hydrogels were synthesized and carefully characterized. The cleavage of DAT-crosslinks with periodate promoted changes in the mechanical and swelling properties of the materials. As expected, a self-healing behavior was observed, based on the spontaneous formation of imine covalent bonds. In addition, we surprisingly found a combination of fast vicinal diols cleavage and a low speed self-crosslinking reaction by imine formation. Consequently, it was found a time-window in which a periodate-treated polymer was obtained in a transient liquid state, which can be exploited to choose the final shape of the material, before automated gelling. The singular properties attained on these hydrogels could be useful for developing sensors, actuators, among other smart systems.</p>

scholarly journals Biohydrogel Based on Dynamic Covalent Bonds for Wound Healing Applications

2021 ◽  
Vol 11 (15) ◽  
pp. 6945
Author(s):  
Chukwuma O. Agubata ◽  
Cynthia C. Mbaoji ◽  
Ifeanyi T. Nzekwe ◽  
César Saldías ◽  
David Díaz Díaz
Keyword(s):  
Wound Healing ◽  
Interfacial Tension ◽  
Blood Clotting ◽  
Phenylboronic Acid ◽  
Moisture Loss ◽  
Self Healing ◽  
Covalent Bonds ◽  
Treatment Groups ◽  
Acid Soluble Collagen ◽  
Thixotropic Behavior

In this work, a biohydrogel based on alginate and dynamic covalent B-O bonds, and derived composites, has been evaluated for wound healing applications. In particular, a phenylboronic acid–alginate (PBA-Alg) complex was synthesized by coupling 3-aminophenylboronic acid onto alginate, and used to prepare varied concentrations of hydrogels and silicate-based nanocomposites in PBS. The resulting hydrogels were characterized in terms of interfacial tension, moisture uptake and loss, interaction with fresh acid-soluble collagen, self-healing ability, effects on blood clotting and wound healing. The interfacial tension between the hydrogels and biorelevant fluids was low and moisture loss of 55%–60% was evident without uptake from the environment. The components of the hydrogels and their mixtures with collagen were found to be compatible. These hydrogels showed efficient self-healing and thixotropic behavior, and the animals in the treatment groups displayed blood clotting times between 9.1 min and 10.7 min. In contrast, the composites showed much longer or shorter clotting times depending on the silicate content. A significant improvement in wound healing was observed in 3% w/v PBA-Alg formulations. Overall, the PBA-Alg hydrogels exhibit self-healing dynamic covalent interactions and may be useful in dressings for incision wounds.

Self-Healing Polymers Based on Reversible Covalent Bonds

2015 ◽  
pp. 1-58 ◽  
Author(s):  
Natascha Kuhl ◽  
Stefan Bode ◽  
Martin D. Hager ◽  
Ulrich S. Schubert
Keyword(s):  
Self Healing ◽  
Covalent Bonds ◽  
Reversible Covalent

scholarly journals Conductive, Stretchable, and Self-healing Ionic Gel Based on Dynamic Covalent Bonds and Electrostatic Interaction

2019 ◽  
Vol 37 (11) ◽  
pp. 1053-1059 ◽  
Author(s):  
Yi Sun ◽  
Yong-Yuan Ren ◽  
Qi Li ◽  
Rong-Wei Shi ◽  
Yin Hu ◽  
...  
Keyword(s):  
Electrostatic Interaction ◽  
Self Healing ◽  
Covalent Bonds

scholarly journals Noncovalent π-stacked robust topological organic framework

2020 ◽  
Vol 117 (34) ◽  
pp. 20397-20403
Author(s):  
Dong Meng ◽  
Jonathan Lee Yang ◽  
Chengyi Xiao ◽  
Rui Wang ◽  
Xiaofei Xing ◽  
...  
Keyword(s):  
Porous Structure ◽  
Organic Semiconductors ◽  
Organic Electronics ◽  
High Performance ◽  
Three Dimensional ◽  
Self Healing ◽  
Direct Construction ◽  
Covalent Bonds ◽  
Practical Applications ◽  
Organic Framework

Organic frameworks (OFs) offer a novel strategy for assembling organic semiconductors into robust networks that facilitate transport, especially the covalent organic frameworks (COFs). However, poor electrical conductivity through covalent bonds and insolubility of COFs limit their practical applications in organic electronics. It is known that the two-dimensional intralayer π∙∙∙π transfer dominates transport in organic semiconductors. However, because of extremely labile inherent features of noncovalent π∙∙∙π interaction, direct construction of robust frameworks via noncovalent π∙∙∙π interaction is a difficult task. Toward this goal, we report a robust noncovalent π∙∙∙π interaction-stacked organic framework, namely πOF, consisting of a permanent three-dimensional porous structure that is held together by pure intralayer noncovalent π∙∙∙π interactions. The elaborate porous structure, with a 1.69-nm supramaximal micropore, is composed of fully conjugated rigid aromatic tetragonal-disphenoid-shaped molecules with four identical platforms. πOF shows excellent thermostability and high recyclability and exhibits self-healing properties by which the parent porosity is recovered upon solvent annealing at room temperature. Taking advantage of the long-range π∙∙∙π interaction, we demonstrate remarkable transport properties of πOF in an organic-field-effect transistor, and the mobility displays relative superiority over the traditional COFs. These promising results position πOF in a direction toward porous and yet conductive materials for high-performance organic electronics.

scholarly journals Doubly Dynamic Hydrogel Formed by Combining Boronate Ester and Acylhydrazone Bonds

Polymers ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 487
Author(s):  
Yusheng Liu ◽  
Yigang Liu ◽  
Qiuxia Wang ◽  
Yugui Han ◽  
Hao Chen ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Diblock Copolymers ◽  
Raft Polymerization ◽  
Solid Content ◽  
Self Healing ◽  
Covalent Bonds ◽  
Boronate Ester ◽  
Isopropyl Acrylamide ◽  
Reversible Addition ◽  
The Difference

The incorporation of double dynamic bonds into hydrogels provides an effective strategy to engineer their performance on demand. Herein, novel hydrogels were PREPARED by combining two kinetically distinct dynamic covalent bonds, boronate ester and acylhydrazone bonds, and the synergistic properties of the hydrogels were studied comprehensively. The functional diblock copolymers P(N-isopropyl acrylamide-co-N-acryloyl-3-aminophenylboronic acid)-b-(N-isopropyl acrylamide-co-diacetone acrylamide) (PAD) were prepared via reversible addition−fragmentation chain transfer (RAFT) polymerization. The hydrogel was constructed by exploiting dynamic reaction of phenyboronic acid moieties with polyvinyl alcohol (PVA) and ketone moieties with adipic dihydrazide (ADH) without any catalyst. The active boronate ester linkage endows the hydrogel with fast gelation kinetics and self-healing ability, and the stable acylhydrazone linkage can enhance the mechanical property of the hydrogel. The difference in kinetics endows that the contribution of each linkage to mechanical strength of the hydrogel can be accurately estimated. Moreover, the mechanical property of the hydrogel can be readily engineered by changing the composition and solid content, as well as by controlling the formation or dissociation of the dynamic linkages. Thus, we provide a promising strategy to design and prepare multi-responsive hydrogels with tunable properties.

A reconfiguring and self-healing thermoset epoxy/chain-extended bismaleimide resin system with thermally dynamic covalent bonds

Polymer ◽  
2018 ◽  
Vol 147 ◽  
pp. 170-182 ◽  
Author(s):  
Zhenjie Ding ◽  
Li Yuan ◽  
Qingbao Guan ◽  
Aijuan Gu ◽  
Guozheng Liang
Keyword(s):  
Self Healing ◽  
Resin System ◽  
Covalent Bonds ◽  
Bismaleimide Resin ◽  
Thermoset Epoxy

The Underlying Chemistry of Self-Healing Materials

MRS Bulletin ◽  
2008 ◽  
Vol 33 (8) ◽  
pp. 759-765 ◽  
Author(s):  
Kyle A. Williams ◽  
Daniel R. Dreyer ◽  
Christopher W. Bielawski
Keyword(s):  
Ring Opening ◽  
State Of The Art ◽  
Noncovalent Interactions ◽  
Self Healing ◽  
Covalent Bonds ◽  
The Past ◽  
Ring Opening Reactions ◽  
Ligand Interactions ◽  
Reversible Covalent ◽  
Metal Ligand

AbstractOver the past ten years, a broad range of self-healing materials, systems that can detect when they have been damaged and heal themselves either spontaneously or with the aid of a stimulus, has emerged. Although many unique compositions and components are used to create these materials, they all employ basic chemical reactions to facilitate repair processes. Kinetically controlled ring-opening reactions and reversible metal–ligand interactions have proven useful in autonomic self-healing materials, which require no stimulus (other than the formation of damage) for operation. In contrast, nonautonomic self-healing materials, which require some type of externally applied stimulus (such as heat or light) to enable healing functions, have capitalized on chemistries that utilize either reversible covalent bonds or various types of noncovalent interactions. This review describes the underlying chemistries used in state-of-the-art self-healing materials, as well as those currently in development.

scholarly journals Rapid self-healing and recycling of multiple-responsive mechanically enhanced epoxy resin/graphene nanocomposites

RSC Advances ◽  
2017 ◽  
Vol 7 (73) ◽  
pp. 46336-46343 ◽  
Author(s):  
Chenting Cai ◽  
Yue Zhang ◽  
Xueting Zou ◽  
Rongchun Zhang ◽  
Xiaoliang Wang ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
High Performance ◽  
Diels Alder ◽  
Self Healing ◽  
Covalent Bonds ◽  
Graphene Nanocomposites ◽  
Graphene Nanocomposite

A rapid self-healing and recyclable high-performance crosslinked epoxy resin (ER)/graphene nanocomposite is reported by simultaneously incorporating thermally reversible Diels–Alder (DA) covalent bonds and multiple-responsive graphene into the ER matrix.

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