Multivalent urea bond assembly of polyacrylate oligomers with improved mechanical strength and high self-healing efficiency

The preparation of room-temperature self-healing polymeric materials with good healing efficiency and high mechanical strength is challenging. Two processes are essential to realise the room-temperature self-healing of materials: (a) a...

Download Full-text

Tough but self-healing and 3D printable hydrogels for E-skin, E-noses and laser controlled actuators

Journal of Materials Chemistry A ◽

10.1039/c9ta04248b ◽

2019 ◽

Vol 7 (43) ◽

pp. 24814-24829 ◽

Cited By ~ 15

Author(s):

Yitian Wang ◽

Qiang Chang ◽

Rixing Zhan ◽

Kaige Xu ◽

Ying Wang ◽

...

Keyword(s):

Graphene Oxide ◽

Mechanical Strength ◽

Polyacrylic Acid ◽

Self Healing ◽

Healing Efficiency ◽

Physically Crosslinked

A versatile hydrogel with extraordinary mechanical strength and self-healing efficiency was developed by integrating physically crosslinked graphene oxide into a chemically crosslinked polyacrylic acid network.

Download Full-text

Developing self-healable and antibacterial polyacrylate coatings with high mechanical strength through crosslinking by multi-amine hyperbranched polysiloxane via dynamic vinylogous urethane

Journal of Materials Chemistry A ◽

10.1039/c7ta04141a ◽

2017 ◽

Vol 5 (32) ◽

pp. 16889-16897 ◽

Cited By ~ 23

Author(s):

Youhao Zhang ◽

Li Yuan ◽

Qingbao Guan ◽

Guozheng Liang ◽

Aijuan Gu

Keyword(s):

Tensile Strength ◽

Mechanical Strength ◽

Self Healing ◽

High Tensile Strength ◽

High Mechanical Strength ◽

Antibacterial Ability ◽

Healing Efficiency ◽

Hyperbranched Polysiloxane

A novel multi-functional polyacrylate coating simultaneously showing high tensile strength, good reversible self-healing efficiency and remarkable antibacterial ability has been developed.

Download Full-text

Dynamic Nanohybrid-Polysaccharide Hydrogels for Soft Wearable Strain Sensing

Sensors ◽

10.3390/s21113574 ◽

2021 ◽

Vol 21 (11) ◽

pp. 3574

Author(s):

Pejman Heidarian ◽

Hossein Yousefi ◽

Akif Kaynak ◽

Mariana Paulino ◽

Saleh Gharaie ◽

...

Keyword(s):

Mechanical Strength ◽

Strain Sensors ◽

Self Healing ◽

Nano Materials ◽

Strain Sensing ◽

Ferric Ions ◽

Research Activity ◽

Adhesion Properties ◽

High Mechanical Strength ◽

The Moment

Electroconductive hydrogels with stimuli-free self-healing and self-recovery (SELF) properties and high mechanical strength for wearable strain sensors is an area of intensive research activity at the moment. Most electroconductive hydrogels, however, consist of static bonds for mechanical strength and dynamic bonds for SELF performance, presenting a challenge to improve both properties into one single hydrogel. An alternative strategy to successfully incorporate both properties into one system is via the use of stiff or rigid, yet dynamic nano-materials. In this work, a nano-hybrid modifier derived from nano-chitin coated with ferric ions and tannic acid (TA/Fe@ChNFs) is blended into a starch/polyvinyl alcohol/polyacrylic acid (St/PVA/PAA) hydrogel. It is hypothesized that the TA/Fe@ChNFs nanohybrid imparts both mechanical strength and stimuli-free SELF properties to the hydrogel via dynamic catecholato-metal coordination bonds. Additionally, the catechol groups of TA provide mussel-inspired adhesion properties to the hydrogel. Due to its electroconductivity, toughness, stimuli-free SELF properties, and self-adhesiveness, a prototype soft wearable strain sensor is created using this hydrogel and subsequently tested.

Download Full-text

Ultrarobust, tough and highly stretchable self-healing materials based on cartilage-inspired noncovalent assembly nanostructure

Nature Communications ◽

10.1038/s41467-021-21577-7 ◽

2021 ◽

Vol 12 (1) ◽

Author(s):

Yuyan Wang ◽

Xin Huang ◽

Xinxing Zhang

Keyword(s):

Spider Silk ◽

Self Healing ◽

High Toughness ◽

Healing Efficiency ◽

Strong Interfacial Interaction ◽

Highly Stretchable ◽

Noncovalent Bonds ◽

Actuation Devices ◽

Noncovalent Bonding ◽

Polyurethane Matrix

AbstractSelf-healing materials integrated with excellent mechanical strength and simultaneously high healing efficiency would be of great use in many fields, however their fabrication has been proven extremely challenging. Here, inspired by biological cartilage, we present an ultrarobust self-healing material by incorporating high density noncovalent bonds at the interfaces between the dentritic tannic acid-modified tungsten disulfide nanosheets and polyurethane matrix to collectively produce a strong interfacial interaction. The resultant nanocomposite material with interwoven network shows excellent tensile strength (52.3 MPa), high toughness (282.7 MJ m‒3, which is 1.6 times higher than spider silk and 9.4 times higher than metallic aluminum), high stretchability (1020.8%) and excellent healing efficiency (80–100%), which overturns the previous understanding of traditional noncovalent bonding self-healing materials where high mechanical robustness and healing ability are mutually exclusive. Moreover, the interfacical supramolecular crosslinking structure enables the functional-healing ability of the resultant flexible smart actuation devices. This work opens an avenue toward the development of ultrarobust self-healing materials for various flexible functional devices.

Download Full-text

Intrinsic Self-Healing Epoxies in Polymer Matrix Composites (PMCs) for Aerospace Applications

Polymers ◽

10.3390/polym13020201 ◽

2021 ◽

Vol 13 (2) ◽

pp. 201

Author(s):

Stefano Paolillo ◽

Ranjita K. Bose ◽

Marianella Hernández Santana ◽

Antonio M. Grande

Keyword(s):

High Performance ◽

Polymer Matrix Composites ◽

Critical Issue ◽

General Description ◽

Self Healing ◽

Matrix Composites ◽

Testing Procedures ◽

Aerospace Applications ◽

Polymer Properties ◽

Healing Efficiency

This article reviews some of the intrinsic self-healing epoxy materials that have been investigated throughout the course of the last twenty years. Emphasis is placed on those formulations suitable for the design of high-performance composites to be employed in the aerospace field. A brief introduction is given on the advantages of intrinsic self-healing polymers over extrinsic counterparts and of epoxies over other thermosetting systems. After a general description of the testing procedures adopted for the evaluation of the healing efficiency and the required features for a smooth implementation of such materials in the industry, different self-healing mechanisms, arising from either physical or chemical interactions, are detailed. The presented formulations are critically reviewed, comparing major strengths and weaknesses of their healing mechanisms, underlining the inherent structural polymer properties that may affect the healing phenomena. As many self-healing chemistries already provide the fundamental aspects for recyclability and reprocessability of thermosets, which have been historically thought as a critical issue, perspective trends of a circular economy for self-healing polymers are discussed along with their possible advances and challenges. This may open up the opportunity for a totally reconfigured landscape in composite manufacturing, with the net benefits of overall cost reduction and less waste. Some general drawbacks are also laid out along with some potential countermeasures to overcome or limit their impact. Finally, present and future applications in the aviation and space fields are portrayed.

Download Full-text

Recyclable Self-Healing Polyurethane Cross-Linked by Alkyl Diselenide with Enhanced Mechanical Properties

Polymers ◽

10.3390/polym11050773 ◽

2019 ◽

Vol 11 (5) ◽

pp. 773 ◽

Cited By ~ 3

Author(s):

Yuqing Qian ◽

Xiaowei An ◽

Xiaofei Huang ◽

Xiangqiang Pan ◽

Jian Zhu ◽

...

Keyword(s):

Mechanical Properties ◽

Room Temperature ◽

Amide Bond ◽

Self Healing ◽

Healing Efficiency ◽

Polyurethane Networks ◽

Combined Action ◽

Cross Linker ◽

Dynamic Structures ◽

External Interventions

Dynamic structures containing polymers can behave as thermosets at room temperature while maintaining good mechanical properties, showing good reprocessability, repairability, and recyclability. In this work, alkyl diselenide is effectively used as a dynamic cross-linker for the design of self-healing poly(urea–urethane) elastomers, which show quantitative healing efficiency at room temperature, without the need for any catalysts or external interventions. Due to the combined action of the urea bond and amide bond, the material has better mechanical properties. We also compared the self-healing effect of alkyl diselenide-based polyurethanes and alkyl disulfide-based polyurethanes. The alkyl diselenide has been incorporated into polyurethane networks using a para-substituted amine diphenyl alkyl diselenide. The resulting materials not only exhibit faster self-healing properties than the corresponding disulfide-based materials, but also show the ability to be processed at temperatures as low as 60 °C.

Download Full-text

Self-healing poly(siloxane-urethane) elastomers with remoldability, shape memory and biocompatibility

Polymer Chemistry ◽

10.1039/c6py01499b ◽

2016 ◽

Vol 7 (47) ◽

pp. 7278-7286 ◽

Cited By ~ 63

Author(s):

Jian Zhao ◽

Rui Xu ◽

Gaoxing Luo ◽

Jun Wu ◽

Hesheng Xia

Keyword(s):

Mechanical Property ◽

Shape Memory ◽

Microphase Separation ◽

Diels Alder ◽

Good Mechanical Property ◽

Self Healing ◽

Healing Efficiency ◽

Good Biocompatibility

The poly(siloxane-urethane) elastomers with microphase separation structure and Diels–Alder bonds show high healing efficiency, good mechanical property and good biocompatibility.

Download Full-text

Numerical Studies of the Effects of Water Capsules on Self-Healing Efficiency and Mechanical Properties in Cementitious Materials

Advances in Materials Science and Engineering ◽

10.1155/2016/8271214 ◽

2016 ◽

Vol 2016 ◽

pp. 1-10 ◽

Cited By ~ 1

Author(s):

Haoliang Huang ◽

Guang Ye

Keyword(s):

Mechanical Properties ◽

Tensile Strength ◽

Elastic Modulus ◽

Cementitious Materials ◽

Self Healing ◽

Negative Effects ◽

Numerical Studies ◽

Healing Efficiency ◽

The Impact ◽

Positive Effect

In this research, self-healing due to further hydration of unhydrated cement particles is taken as an example for investigating the effects of capsules on the self-healing efficiency and mechanical properties of cementitious materials. The efficiency of supply of water by using capsules as a function of capsule dosages and sizes was determined numerically. By knowing the amount of water supplied via capsules, the efficiency of self-healing due to further hydration of unhydrated cement was quantified. In addition, the impact of capsules on mechanical properties was investigated numerically. The amount of released water increases with the dosage of capsules at different slops as the size of capsules varies. Concerning the best efficiency of self-healing, the optimizing size of capsules is 6.5 mm for capsule dosages of 3%, 5%, and 7%, respectively. Both elastic modulus and tensile strength of cementitious materials decrease with the increase of capsule. The decreasing tendency of tensile strength is larger than that of elastic modulus. However, it was found that the increase of positive effect (the capacity of inducing self-healing) of capsules is larger than that of negative effects (decreasing mechanical properties) when the dosage of capsules increases.

Download Full-text