Spatial resolution comparison of AC-SECM with SECM and their characterization of self-healing performance of hexamethylene diisocyanate trimer microcapsule coatings

2015 ◽  
Vol 3 (10) ◽  
pp. 5599-5607 ◽  
Author(s):  
Wei Wang ◽  
Likun Xu ◽  
Huyuan Sun ◽  
Xiangbo Li ◽  
Shouhuan Zhao ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Spatial Resolution ◽  
Healing Process ◽  
The Self ◽  
Hexamethylene Diisocyanate ◽  
Self Healing ◽  
Functional Additives

ACSECM monitored the self-healing process of scratched epoxy resin coatings with hexamethylene diisocyanate trimer microcapsules as functional additives.

MECHANICAL PROPERTIES AND SELF-HEALING MECHANISM OF EPOXY MORTAR

2015 ◽  
Vol 77 (12) ◽  
Author(s):  
Nur Farhayu Ariffin ◽  
Mohd Warid Hussin ◽  
Abdul Rahman Mohd Sam ◽  
Han Seung Lee ◽  
Nur Hafizah A. Khalid ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Healing Process ◽  
Control Sample ◽  
Pulse Velocity ◽  
The Self ◽  
Fine Aggregate ◽  
Self Healing ◽  
Velocity Measurements ◽  
Hydroxyl Ion ◽  
Healing Agent

Crack deformation in concrete start with hairline crack or micro-crack which can lead to major crack if not prevented. Crack can cause a major deterioration to the structure as liquid can penetrate inside and cause damage as a result; the durability of concrete will decrease. Self-healing concrete was introduced to automatically repair hairline crack or micro-crack without external intervention. Previous study had shown that by introducing bacteria into the concrete, the crack will heal itself. This paper presents the study on self-healing mortar by using epoxy resin without hardener as a self-healing agent. The self-healing process was evaluated using Ultrasonic Pulse Velocity measurements up to 180 days. Mortar specimens were prepared with mass ratio of 1:3 (cement: fine aggregate), water-cement ratio of 0.48 and 10% epoxy resin of cement content. All tested specimens were subjected to wet-dry curing; where compressive strength, flexural strength, and tensile splitting strength and self-healing mechanism were measured. The results obtained shows that, all strength properties of the self-healing epoxy mortar were significantly higher than the control sample and became constant at 10 % of epoxy resin content. Based on the pulse velocity measurements, after 60 days the cracks of the mortar healed automatically as a result of the reaction between the unhardened epoxy resin and hydroxyl ion from cement hydrate. This shows the ability of the epoxy to be used as self-healing agent. 

scholarly journals Application of GGBFS and Bentonite to Auto-Healing Cracks of Cement Paste

2018 ◽  
Vol 1 (1) ◽  
pp. 38 ◽  
Author(s):  
J J Ekaputri ◽  
M S Anam ◽  
Y Luan ◽  
C Fujiyama ◽  
N Chijiwa ◽  
...  
Keyword(s):  
Cement Paste ◽  
Surface Crack ◽  
Crack Width ◽  
Healing Process ◽  
Crack Depth ◽  
The Self ◽  
External Loading ◽  
Self Healing ◽  
Carbonation Reaction ◽  
Granulated Blast Furnace Slag

Cracks are caused by many factors. Shrinkage and external loading are the most common reason. It becomes a problem when the ingression of aggressive and harmful substance penetrates to the concrete gap. This problem reduces the durability of the structures. It is well known that self – healing of cracks significantly improves the durability of the concrete structure. This paper presents self-healing cracks of cement paste containing bentonite associated with ground granulated blast furnace slag. The self-healing properties were evaluated with four parameters: crack width on the surface, crack depth, tensile strength recovery, and flexural recovery. In combination with microscopic observation, a healing process over time is also performed. The results show that bentonite improves the healing properties, in terms of surface crack width and crack depth. On the other hand, GGBFS could also improve the healing process, in terms of crack depth, direst tensile recovery, and flexural stiffness recovery. Carbonation reaction is believed as the main mechanism, which contributes the self-healing process as well as the continuous hydration progress.

The effects of textile reinforcements on the protective properties of self-healing polymers intended for safety gloves

2020 ◽  
Vol 90 (17-18) ◽  
pp. 1974-1986
Author(s):  
Emilia Irzmańska ◽  
Anna Bacciarelli-Ulacha ◽  
Agnieszka Adamus-Włodarczyk ◽  
Anna Strąkowska
Keyword(s):  
Healing Process ◽  
Polymeric Composite ◽  
Polymeric Materials ◽  
Economic Loss ◽  
The Self ◽  
Raw Material ◽  
Protective Equipment ◽  
Self Healing ◽  
Hybrid Molecules ◽  
The Impact

In the environment where glove material is exposed to harmful chemicals, hazards related to faster penetration of dangerous substances into the glove interior may cause microdamage. One of the solutions to overcome this problem is to use the self-healing polymeric materials that can minimize economic loss and accidents in the workplace. The current work aims to present the impact of different types of textile reinforcement on the effectiveness and efficiency of the self-healing process of methyl vinyl silicone rubber containing hybrid molecules with an inorganic silsesquioxane intended for use on all-rubber gloves. Three knitted fabrics with a similar structure and differentiated raw material composition were selected: polyamide, cotton–polyamide, and cotton. Evaluation of the self-healing process of the elastomeric composite to personal protective equipment was performed. For this purpose the assessment of the surface morphology of materials has been performed before and after the self-healing process. The implementation of knitted fabric into the polymeric composite in the tested samples allowed us to obtain the best results in all tests. The studied composite samples exhibited an increased resistance to three types of damage: penetration, abrasion and puncture. The samples also underwent the self-healing processes and regeneration after a proper conditioning period. Thus, the obtained results confirmed the possibility of using tested elastomeric composites in the construction of protective gloves and showed an effectivity of the self-healing process for the long-term usage of that protective equipment.

Molecular dynamics simulation insight into the temperature dependence and healing mechanism of an intrinsic self-healing polyurethane elastomer

2020 ◽  
Vol 22 (31) ◽  
pp. 17620-17631
Author(s):  
Xianling Chen ◽  
Jing Zhu ◽  
Yanlong Luo ◽  
Jun Chen ◽  
Xiaofeng Ma ◽  
...  
Keyword(s):  
Molecular Dynamics ◽  
Molecular Dynamics Simulation ◽  
Hydrogen Bonds ◽  
Molecular Diffusion ◽  
Healing Process ◽  
The Self ◽  
Dynamics Simulation ◽  
Polyurethane Elastomer ◽  
Self Healing ◽  
Insight Into

The changes in the type and number of hydrogen bonds as well as the microscopic behavior of molecular diffusion in the self-healing process of polyurethane are revealed.

scholarly journals Experimental Characterization of the Self-Healing Capacity of Cement Based Materials: An Overview

Proceedings ◽  
2018 ◽  
Vol 2 (8) ◽  
pp. 454 ◽  
Author(s):  
Liberato Ferrara ◽  
Estefania Cuenca Asensio ◽  
Francesco Lo Monte ◽  
Marta Roig Flores ◽  
Mercedes Sanchez Moreno ◽  
...  
Keyword(s):  
The Self ◽  
Self Healing ◽  
Experimental Characterization ◽  
Cement Based Materials

scholarly journals The Self-Healing Performance of Carbon-Based Nanomaterials Modified Asphalt Binders Based on Molecular Dynamics Simulations

2021 ◽  
Vol 7 ◽  
Author(s):  
Yan Gong ◽  
Jian Xu ◽  
Er-hu Yan ◽  
Jun-hua Cai
Keyword(s):  
Healing Process ◽  
Asphalt Binder ◽  
Mean Square Displacement ◽  
The Self ◽  
Asphalt Binders ◽  
Self Healing ◽  
Modified Asphalt ◽  
Healing Efficiency ◽  
Carbon Based Nanomaterials ◽  
Carbon Based

In this study, the molecular dynamics simulation was used to explore the effects of carbon-based nanomaterials as binder modifiers on self-healing capability of asphalt binder and to investigate the microscopic self-healing process of modified asphalt binders under different temperature. An asphalt average molecular structure model of PEN70 asphalt binder was constructed firstly. Further, three kinds of carbon-based nanomaterials were added at three different percentages ranging from 0.5 to 1.5% to the base binder to study their effects on the self-healing capability, including two carbon nanotubes (CNT1 and CNT2) and graphene nanoflakes. Combining with the three-dimensional (3D) microcrack model to simulate the asphalt self-healing process, the density analysis, relative concentration analysis along OZ direction, and mean square displacement analysis were performed to investigate the temperature sensitive self-healing characters. Results showed that the additions of CNTs were effective in enhancing the self-healing efficiency of the plain asphalt binder. By adding 0.5% CNT1 and 0.5% CNT2, about 652% and 230% of the mean square displacement of plain asphalt binder were enhanced at the optimal temperatures. However, the use of graphene nanoflakes as an asphalt modifier did not provide any noticeable changes on the self-healing efficiency. It can be found that the self-healing capability of the asphalt was closely related to the temperature. For base asphalt, the self-healing effect became especially high at the phase transition temperature range, while, for the modified asphalt, the enhancement of the self-healing capability at the low phase transition temperature (15°C) became negligible. In general, the optimal healing temperature range of the CNTs modified asphalt binders is determined as 45–55°C and the optimal dosage of the CNTs is about 0.5% over the total weight of the asphalt binder. Considering the effect of carbon-based nanomaterials on the self-healing properties, the recommended carbon-based nanomaterials modifier is CNT1 with the aspect ratio of 1.81.

scholarly journals A Self-Healing Coating with UV-Shielding Property

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 421 ◽  
Author(s):  
Lei Peng ◽  
Musong Lin ◽  
Sheng Zhang ◽  
Li Li ◽  
Qiang Fu ◽  
...  
Keyword(s):  
Moisture Absorption ◽  
Healing Process ◽  
Ultra Violet ◽  
The Self ◽  
Self Healing ◽  
Soft Substrate ◽  
Water Contact ◽  
Uv Shielding ◽  
Host Guest Complex ◽  
Healing Property

A self-healing coating with UV-shielding property was prepared in this paper. The self-healing property was based on the inclusion between a host (β-CD-TiO2) and a guest HEMA-Ad). After inclusion of the host and guest, the host–guest complex (HEMA-Ad/β-CD-TiO2) was polymerized with other reactive monomers (HEMA and BA) to obtain the final coating. The coating had good hydrophobicity (water contact angle >90°, moisture absorption rate <2%) and excellent UV-shielding performance (ultra-violet protect factor >90%), and could be firmly bonded to a soft substrate. In addition, the coating had good self-healing property, which means that cracks in the material can recover many times after being damaged and that the UV-shielding ability can be fully restored with the self-healing process.

A selected bacterial strain for the self-healing process in cementitious specimens without cell immobilization steps

2020 ◽  
Author(s):  
Romario P. Santos ◽  
Tatiane M. Ramos ◽  
Brendo M. Borges ◽  
Luciana M. Hollanda ◽  
Álvaro S. Lima ◽  
...  
Keyword(s):  
Bacterial Strain ◽  
Healing Process ◽  
Cell Immobilization ◽  
The Self ◽  
Self Healing
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