Equipment-free photothermal effect promoted self-healing and self-recovery of hydrogels

Soft Matter ◽  
2020 ◽  
Vol 16 (43) ◽  
pp. 9833-9837
Author(s):  
Xinjie Zhang ◽  
Xuechen Liang ◽  
Qichen Huang ◽  
Han Zhang ◽  
Changkun Liu ◽  
...  
Keyword(s):  
Service Life ◽  
Soft Materials ◽  
The Self ◽  
Photothermal Effect ◽  
Self Healing ◽  
Synthetic Process ◽  
Self Repair

The self-repair of hydrogel materials can be promoted under sunlight by adding a light-to-heat conversion substance during the synthetic process, which will greatly extend the service life of soft materials in the off-grid areas.

Self-Healing Coatings to Mitigate Post-Impact Corrosion

CORROSION ◽  
10.5006/2382 ◽  
2017 ◽  
Vol 73 (9) ◽  
pp. 1091-1097 ◽  
Author(s):  
Atousa Plaseied ◽  
Allen Skaja ◽  
Ramanathan Lalgudi ◽  
Christine Henderson
Keyword(s):  
Service Life ◽  
Exposure Period ◽  
Metal Substrate ◽  
The Self ◽  
Coating System ◽  
Self Healing ◽  
Polymeric Coatings ◽  
Metallic Structures ◽  
Post Impact ◽  
Salt Fog

Self-healing polymeric coatings have offered tremendous potential for repairing damage and extending the service life and safety of metallic structures. There have been many challenges associated with the catalyst activated version of the self-healing oligomer filled microcapsule coating additives (or microbeads) technology, but a non-catalyst version appears more promising. The objective of this study was to identify the effect of self-healing coatings in an epoxy coating system containing the non-catalyst microbeads on post-impact corrosion mitigation of water infrastructure. Experimental results showed that coatings containing microbeads did not fully prevent corrosion of the post-impact exposed metal substrate over the exposure period for this study, especially in salt fog and immersion conditions. However, this coating showed less coating degradation compared to the coating without the presence of microbeads.

scholarly journals Room-Temperature Self-Healing Elastomer based on Van der Waals Forces in Air and under Water

2021 ◽  
Vol 2083 (2) ◽  
pp. 022066
Author(s):  
Pengying Niu ◽  
Beibei Liu ◽  
Huanjun Li
Keyword(s):  
Room Temperature ◽  
Van Der Waals ◽  
Strong Acid ◽  
Van Der Waals Forces ◽  
The Self ◽  
Self Healing ◽  
Wearable Electronic ◽  
Self Repair ◽  
High Humidity Environment ◽  
Wearable Electronic Devices

Abstract With the development of flexible wearable electronic devices, researches on self-healing conductive materials have become prevalent. However, the self-healing performance of most conductive self-healing materials is commonly achieved by the external stimulus that may cause damage to the equipment. Pparticularly, these self-healing materials may lose the self-healing properties when exposed to a high-humidity environment. Here, we adopted two hydrophobic monomers (2-methoxyethyl acrylate and ethyl methacrylate) to obtain a self-healing elastomer that could display self-healing properties in air or under water though van der Waals forces. The quality and mechanical properties of the elastomer material could keep stable after stored under water for half a month. This elastomer material was capable of self-healing in different environments with self-repair efficiencies more than 50% in deionized water, strong acid solution and strong alkaline solution. The self-repair efficiencies were up to 77% at room temperature(T=25°C) and 64% at low temperature (T=-20°C) in air.

scholarly journals Rapid and Local Self-Healing Ability of Polyurethane Nanocomposites Using Photothermal Polydopamine-Coated Graphene Oxide Triggered by Near-Infrared Laser

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1274
Author(s):  
Yu-Mi Ha ◽  
Young Nam Kim ◽  
Yong Chae Jung
Keyword(s):  
Graphene Oxide ◽  
Near Infrared ◽  
Resonance Effect ◽  
The Self ◽  
Ex Situ ◽  
Photothermal Effect ◽  
Self Healing ◽  
Local Surface Plasmon Resonance ◽  
X Ray ◽  
Nir Laser

In this study, we report the self-healing ability of polyurethane (PU) nanocomposites based on the photothermal effect of polydopamine-coated graphene oxide (PDA–rGO). Polydopamine (PDA) was coated on the graphene oxide (GO) surface, while simultaneously reducing GO by the oxidation of dopamine hydrochloride in an alkaline aqueous solution. The PDA–rGO was characterized by Fourier-transform infrared spectroscopy, X-ray diffraction, Raman spectroscopy, thermogravimetric analysis, and scanning electron microscopy–energy-dispersive X-ray analysis. PDA–rGO/PU nanocomposites with nanofiller contents of 0.1, 0.5 and 1 wt% were prepared by ex situ mixing method. The photothermal effect of the PDA–rGO in the PU matrix was investigated at 0.1 W/cm2 using an 808 nm near-infrared (NIR) laser. The photothermal properties of the PDA–rGO/PU nanocomposites were superior to those of the GO/PU nanocomposites, owing to an increase in the local surface plasmon resonance effect by coating with PDA. Subsequently, the self-healing efficiency was confirmed by recovering the tensile stress of the damaged nanocomposites using the thermal energy generated by the NIR laser.

A Self-Repair Mode for Capillary Reinforced Polymer Composite

2013 ◽  
Vol 575-576 ◽  
pp. 147-150
Author(s):  
Xin Hua Yuan ◽  
Ji Ye Wu ◽  
Yong Qiang Liu ◽  
Jun Xia Mao ◽  
Xue Tao Ou ◽  
...  
Keyword(s):  
Impact Damage ◽  
The Self ◽  
Self Healing ◽  
Reinforced Polymer ◽  
Flexural Testing ◽  
Reinforced Plastic ◽  
Crack Morphology ◽  
Healing Agent ◽  
Self Repair ◽  
The Impact

The paper describes a novel capillary reinforced plastic which can self-repair the impact damage in polymer composites through employing a bio-mimetic approach. A epoxy resin E-51 and harder WSR706# was used as the healing agent, the two components being filled in to different directions (0°and 90° fibers). Impact test and tensile test were used as a measure of the self-healing effectiveness. The results of flexural testing have shown that strength lost after impact damage can be restored by the self-healing effect with healing agent stored in capillaries, and a significant fraction (about 79%) of lost mechanical strength is restored by this effect. At the same time, the paper also studied the morphology of fracture surface of no embedded and capillaries embedded sample. And micrographs of crack morphology which has been healed have been observed.

Experimental studies on the development of a self-healing cementitious matrix for repair and retrofitting of concrete structures

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Dibyendu Adak ◽  
Donkupar Francis Marbaniang ◽  
Subhrajit Dutta
Keyword(s):  
Service Life ◽  
Mechanical Strength ◽  
Concrete Structure ◽  
Concrete Structures ◽  
The Self ◽  
Self Healing ◽  
Content Type ◽  
Cementitious Matrix ◽  
Healing Period ◽  
Strength And Durability

PurposeSelf-healing concrete is a revolutionary building material that will generally reduce the maintenance cost of concrete constructions. Self-healing of cracks in concrete structure would contribute to a longer service life of the concrete and would make the material more durable and more sustainable. The cementitious mortar with/without incorporating encapsulates at different percentages of slag replacement with the cement mix improves autogenous healing at different ages. Therefore, this study’s aim is to develop a self-healing cementitious matrix for repair and retrofitting of concrete structures.Design/methodology/approachIn the present work, waste straw pipes are used as a capsule, filled with the solution of sodium hydroxide (NaOH), sodium silicate (Na2SiO3) and colloidal nano-silica as self-healing activators. An artificial micro-crack on the control and blended mortar specimens at different percentages of slag replacement with cement (with/without encapsulation) is developed by applying a compressive load of 50% of its ultimate load-carrying capacity. The mechanical strength and ultrasonic pulse velocity, water absorption and chloride ion penetration test are conducted on the concrete specimen before and after the healing period. Finally, the self-healing activity of mortar mixes with/without encapsulation is analysed at different ages.FindingsThe encapsulated mortar mix with 10% of slag content has better self-healing potential than all other mixes considering mechanical strength and durability. The enhancement of the self-healing potential of such mortar mix is mainly due to hydration of anhydrous slag on the crack surface and transformation of amorphous slag to the crystalline phase in presence of encapsulated fluid.Research limitations/implicationsThe self-healing activities of the slag-based cementitious composite are studied for a healing period of 90 days only. The strength and durability performance of the cracked specimen may be increased after a long healing period.Practical implicationsThe outcome of the work will help repair the cracks in the concrete structure and enhances the service life.Originality/valueThis study identifies the addition encapsulates with a self-healing activator fluid that can recover its strength after minor damage.

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