scispace - formally typeset

Journal ArticleDOI

A Thermally Re-mendable Cross-Linked Polymeric Material

01 Mar 2002-Science (American Association for the Advancement of Science)-Vol. 295, Iss: 5560, pp 1698-1702

TL;DR: A transparent organic polymeric material that can repeatedly mend or “re-mend” itself under mild conditions and is a tough solid at room temperature and below with mechanical properties equaling those of commercial epoxy resins.
Abstract: We have developed a transparent organic polymeric material that can repeatedly mend or "re-mend" itself under mild conditions. The material is a tough solid at room temperature and below with mechanical properties equaling those of commercial epoxy resins. At temperatures above 120 degrees C, approximately 30% (as determined by solid-state nuclear magnetic resonance spectroscopy) of "intermonomer" linkages disconnect but then reconnect upon cooling, This process is fully reversible and can be used to restore a fractured part of the polymer multiple times, and it does not require additional ingredients such as a catalyst, additional monomer, or special surface treatment of the fractured interface.
Topics: Self-healing material (53%)
Citations
More filters

Journal ArticleDOI
01 Nov 2013-Advanced Materials
TL;DR: Electronic networks comprised of flexible, stretchable, and robust devices that are compatible with large-area implementation and integrated with multiple functionalities is a testament to the progress in developing an electronic skin akin to human skin.
Abstract: Human skin is a remarkable organ. It consists of an integrated, stretchable network of sensors that relay information about tactile and thermal stimuli to the brain, allowing us to maneuver within our environment safely and effectively. Interest in large-area networks of electronic devices inspired by human skin is motivated by the promise of creating autonomous intelligent robots and biomimetic prosthetics, among other applications. The development of electronic networks comprised of flexible, stretchable, and robust devices that are compatible with large-area implementation and integrated with multiple functionalities is a testament to the progress in developing an electronic skin (e-skin) akin to human skin. E-skins are already capable of providing augmented performance over their organic counterpart, both in superior spatial resolution and thermal sensitivity. They could be further improved through the incorporation of additional functionalities (e.g., chemical and biological sensing) and desired properties (e.g., biodegradability and self-powering). Continued rapid progress in this area is promising for the development of a fully integrated e-skin in the near future.

1,572 citations


Journal ArticleDOI
Jian Liu1, Jian Liu2, Tianyu Yang2, Dawei Wang2  +4 moreInstitutions (4)
Abstract: The controlled synthesis of monodisperse nanospheres faces a number of difficulties, such as extensive crosslinking during hydrothermal processes. Here, the authors show a route for the controlled synthesis of mesoporous polymer nanospheres, which can be further converted into carbon nanospheres through carbonization.

1,475 citations


Journal ArticleDOI
21 Apr 2011-Nature
TL;DR: This work presents metallosupramolecular polymers that can be mended through exposure to light, which consist of telechelic, rubbery, low-molecular-mass polymers with ligand end groups that are non-covalently linked through metal-ion binding.
Abstract: Smart materials with an in-built ability to repair damage caused by normal wear and tear could prove useful in a wide range of applications. Most healable polymer-based materials so far developed require heating of the damaged area. But Burnworth et al. have now produced materials — in the form of polymer strands linked through metal complexes — that can be mended through exposure to light. The metal complexes in these materials can absorb ultraviolet light that is then converted into heat, which temporarily unlinks the polymer strands for quick and efficient defect healing. In principle, healing can take place in situ and while under load. Polymers with the ability to repair themselves after sustaining damage could extend the lifetimes of materials used in many applications1. Most approaches to healable materials require heating the damaged area2,3,4. Here we present metallosupramolecular polymers that can be mended through exposure to light. They consist of telechelic, rubbery, low-molecular-mass polymers with ligand end groups that are non-covalently linked through metal-ion binding. On exposure to ultraviolet light, the metal–ligand motifs are electronically excited and the absorbed energy is converted into heat. This causes temporary disengagement of the metal–ligand motifs and a concomitant reversible decrease in the polymers’ molecular mass and viscosity5, thereby allowing quick and efficient defect healing. Light can be applied locally to a damage site, so objects can in principle be healed under load. We anticipate that this approach to healable materials, based on supramolecular polymers and a light–heat conversion step, can be applied to a wide range of supramolecular materials that use different chemistries.

1,291 citations


Journal ArticleDOI
11 Nov 2009-Chemical Reviews
TL;DR: This paper aims to demonstrate the efforts towards in-situ applicability of EMMARM, which aims to provide real-time information about the physical properties of EMTs and their applications in the treatment of cancer.
Abstract: Department of Chemistry, Department of Radiology, Washington University in Saint Louis, Saint Louis, Missouri 63130, Department of Chemistry, Texas A&M University, College Station, Texas 77842, Cancer Center Karolinska, Department of Oncology-Pathology CCK, R8:03 Karolinska Hospital and Institute, SE-171 76 Stockholm, Sweden, and Department of Chemistry and Biochemistry, Department of Materials, and Materials Research Laboratory, University of California, Santa Barbara, California 93106

1,256 citations


Journal ArticleDOI
01 Aug 2007-Nature Materials
TL;DR: A self-healing system capable of autonomously repairing repeated damage events via a three-dimensional microvascular network embedded in the substrate is reported, opening new avenues for continuous delivery of healing agents for self-repair as well as other active species for additional functionality.
Abstract: Self-healing polymers composed of microencapsulated healing agents exhibit remarkable mechanical performance and regenerative ability, but are limited to autonomic repair of a single damage event in a given location. Self-healing is triggered by crack-induced rupture of the embedded capsules; thus, once a localized region is depleted of healing agent, further repair is precluded. Re-mendable polymers can achieve multiple healing cycles, but require external intervention in the form of heat treatment and applied pressure. Here, we report a self-healing system capable of autonomously repairing repeated damage events. Our bio-inspired coating-substrate design delivers healing agent to cracks in a polymer coating via a three-dimensional microvascular network embedded in the substrate. Crack damage in the epoxy coating is healed repeatedly. This approach opens new avenues for continuous delivery of healing agents for self-repair as well as other active species for additional functionality.

1,228 citations


References
More filters

Journal ArticleDOI
15 Feb 2001-Nature
TL;DR: A structural polymeric material with the ability to autonomically heal cracks is reported, which incorporates a microencapsulated healing agent that is released upon crack intrusion and polymerization of the healing agent is triggered by contact with an embedded catalyst, bonding the crack faces.
Abstract: Structural polymers are susceptible to damage in the form of cracks, which form deep within the structure where detection is difficult and repair is almost impossible. Cracking leads to mechanical degradation of fibre-reinforced polymer composites; in microelectronic polymeric components it can also lead to electrical failure. Microcracking induced by thermal and mechanical fatigue is also a long-standing problem in polymer adhesives. Regardless of the application, once cracks have formed within polymeric materials, the integrity of the structure is significantly compromised. Experiments exploring the concept of self-repair have been previously reported, but the only successful crack-healing methods that have been reported so far require some form of manual intervention. Here we report a structural polymeric material with the ability to autonomically heal cracks. The material incorporates a microencapsulated healing agent that is released upon crack intrusion. Polymerization of the healing agent is then triggered by contact with an embedded catalyst, bonding the crack faces. Our fracture experiments yield as much as 75% recovery in toughness, and we expect that our approach will be applicable to other brittle materials systems (including ceramics and glasses).

3,290 citations


Journal ArticleDOI
Carolyn M. Dry1Institutions (1)
Abstract: An investigation was made into the feasibility of developing polymer matrix composites which have the ability to self-repair internal cracks due to mechanical loading. It focused on the cracking of hollow repair fibers dispersed in a matrix and the subsequent timed release of repair chemicals which result in the sealing of matrix cracks, the restoration of strength in damaged areas and the ability to retard crack propagation. These materials, capable of passive, smart self-repair, consist of several parts: (1) an agent of internal deterioration such as dynamic loading which induces cracking; (2) a stimulus to release the repairing chemical such as the cracking of a fiber; (3) a fiber; (4) a repair chemical monomer carried inside the fiber either a part polymer or a monomer; and (5) a method of hardening the chemical in the matrix in the case of crosslinking polymers or a method of drying the matrix in the case of a monomer. It was found that cracking of the repair fiber and subsequent release of the repair chemicals could be achieved. Release of chemicals into cracks was observed using optical microscopy. Impact fracture and bend tests were performed and revealed the ability of this system to fill and repair cracks, restore strength and retard crack growth. This work was accomplished by Natural Process Design. These results were positive.

446 citations


Journal ArticleDOI
K. Jud1, Henning-H. Kausch1, J. G. Williams1Institutions (1)
Abstract: Compact tension tests have been performed on re-healed and welded glassy polymers (PMMA-PMMA, SAN-SAN and PMMA-SAN). At temperatures above the glass transition temperature,Tg, it was observed that the facture toughness,KIi, in the interface increased with contact time,t, asKIi ∝t1/4 as predicted by a diffusion model. The self-diffusion constantD(Tg + 15 K) of chains of molecular weight 1.2×105 can be estimated as 1×10−21sec−1 with an activation energy of 274 kJ mol−1. For full material resistance, the depth of interdiffusion, 〈Δx2〉1/2, was calculated to be between 2 and 3 nm. Vacuum drying of the specimens, as well as polishing the interfaces, decreases the speed of interdiffusion.

435 citations


Book ChapterDOI
John M. Barton1Institutions (1)
01 Jan 1985-
Abstract: This review is on the use of differential scanning calorimetry as a method of monitoring and investigating the kinetics of epoxy resin curing reactions. Some instrumental and experimental aspects are discussed, including methods of analysing the kinetic data. A brief survey is made of epoxy resin curing reactions and results of DSC studies are reviewed. These results are concerned with the use of carboxylic acid anhydrides, primary and secondary amines, dicyanodiamide, and imidazoles as curing agents.

263 citations


Journal ArticleDOI
01 May 1990-Macromolecules
Abstract: Un hydrogel a base de polyoxazoline est prepare par reaction de Diels-Alder entre un poly(N-acetylethylenimine) (PAEI) modifie par le furane et un PAEI modifie par le maleimide. Le comportement du gonflement de l'hydrogel est etudie en fonction de la teneur en groupements fonctionnels dans le prepolymere. L'interconversion reversible entre l'hydrogel et le polymere lineaire soluble est realisee par un changement de temperature

239 citations


Network Information
Related Papers (5)
15 Feb 2001, Nature

Scott R. White, Nancy R. Sottos +8 more

21 Feb 2008, Nature

Philippe Cordier, François Tournilhac +2 more

21 Apr 2011, Nature

Mark Burnworth, Li-Ming Tang +7 more

18 Nov 2011, Science

Damien Montarnal, Mathieu Capelot +2 more

01 Aug 2007, Nature Materials

Kathleen S. Toohey, Nancy R. Sottos +3 more

Performance
Metrics
No. of citations received by the Paper in previous years
YearCitations
20224
2021173
2020211
2019180
2018147
2017162