scholarly journals In-depth characterization of self-healing polymers based on π–π nteractions

2021 ◽  
Vol 17 ◽  
pp. 2496-2504
Author(s):  
Josefine Meurer ◽  
Julian Hniopek ◽  
Johannes Ahner ◽  
Michael Schmitt ◽  
Jürgen Popp ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Mechanical Damage ◽  
Analytical Techniques ◽  
The Self ◽  
Supramolecular Interactions ◽  
Supramolecular Polymers ◽  
Self Healing ◽  
Noncovalent Bonds ◽  
Tetracarboxylic Dianhydride

The self-healing behavior of two supramolecular polymers based on π–π-interactions featuring different polymer backbones is presented. For this purpose, these polymers were synthesized utilizing a polycondensation of a perylene tetracarboxylic dianhydride with polyether-based diamines and the resulting materials were investigated using various analytical techniques. Thus, the molecular structure of the polymers could be correlated with the ability for self-healing. Moreover, the mechanical behavior was studied using rheology. The activation of the supramolecular interactions results in a breaking of these noncovalent bonds, which was investigated using IR spectroscopy, leading to a sufficient increase in mobility and, finally, a healing of the mechanical damage. This scratch-healing behavior was also quantified in detail using an indenter.

scholarly journals A study on the wetting properties of broccoli leaf surfaces and their time dependent self-healing after mechanical damage

Soft Matter ◽  
2018 ◽  
Vol 14 (38) ◽  
pp. 7782-7792 ◽  
Author(s):  
Benjamin B. Rich ◽  
Boaz Pokroy
Keyword(s):  
Surface Roughness ◽  
Mechanical Damage ◽  
The Self ◽  
Time Dependent ◽  
Self Healing ◽  
Wetting Properties ◽  
Leaf Surfaces

This paper reports the self-healing of broccoli leaves after mechanical damage; connecting recovery of surface roughness to the wetting properties.

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 Effect of Molecular Structure in the Chain Mobility of Dichalcogenide-Based Polymers with Self-Healing Capacity

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1960 ◽  
Author(s):  
Mikel Irigoyen ◽  
Jon M. Matxain ◽  
Fernando Ruipérez
Keyword(s):  
Molecular Structure ◽  
Exchange Reaction ◽  
Initial Guess ◽  
The Self ◽  
Self Healing ◽  
Chain Mobility ◽  
Reaction Barriers ◽  
Dynamics Simulations ◽  
Two Parameters ◽  
Simulation Parameters

Recently, it has been shown that the reaction mechanism in self-healing diphenyl dichalcogenide-based polymers involves the formation of sulfenyl and selenyl radicals. These radicals are able to attack a neighbouring dichalcogenide bond via a three-membered transition state, leading to the interchange of chalcogen atoms. Hence, the chain mobility is crucial for the exchange reaction to take place. In this work, molecular dynamics simulations have been performed in a set of disulfide- and diselenide-based materials to analyze the effect of the molecular structure in the chain mobility. First of all, a validation of the computational protocol has been carried out, and different simulation parameters like initial guess, length of the molecular chains, size of the simulation box and simulation time, have been evaluated. This protocol has been used to study the chain mobility and also the self-healing capacity, which depends on the probability to generate radicals ( ρ ), the barrier of the exchange reaction ( Δ G ) and the mobility of the chains ( ω ). The first two parameters have been obtained in previous quantum chemical calculations on the systems under study in this work. After analyzing the self-healing capacity, it is concluded that aromatic diselenides (PD-SeSe) are the best candidates among those studied to show self-healing, due to lower reaction barriers and larger ω values.

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.

Influence of Aspartate Moieties on the Self-Healing Behavior of Histidine-Rich Supramolecular Polymers

2018 ◽  
Vol 39 (17) ◽  
pp. 1700742 ◽  
Author(s):  
Marcel Enke ◽  
Lukas Köps ◽  
Stefan Zechel ◽  
Johannes C. Brendel ◽  
Jürgen Vitz ◽  
...  
Keyword(s):  
The Self ◽  
Supramolecular Polymers ◽  
Self Healing

The preparation and characterization of double-layer microcapsules used for the self-healing of resin matrix composites

2012 ◽  
Vol 22 (48) ◽  
pp. 25437 ◽  
Author(s):  
Ru Tian ◽  
Xiaoli Fu ◽  
Yudong Zheng ◽  
Xin Liang ◽  
Qiaoli Wang ◽  
...  
Keyword(s):  
Double Layer ◽  
The Self ◽  
Resin Matrix ◽  
Self Healing ◽  
Matrix Composites

Evaluation of Self-Healing in Concrete by Means of Analytical Techniques

2020 ◽  
Vol 309 ◽  
pp. 38-43
Author(s):  
Konstantinos Aspiotis ◽  
Konstantinos Sotiriadis ◽  
Ivana Kumpová ◽  
Petra Mácová ◽  
Efstratios Badogiannis ◽  
...  
Keyword(s):  
Crack Width ◽  
Healing Process ◽  
Analytical Techniques ◽  
Dicarboxylic Acids ◽  
The Self ◽  
Experimental Methodology ◽  
Self Healing ◽  
Micro Computed Tomography ◽  
Binder Ratio ◽  
Water To Binder Ratio

In the present work, the self-healing process in concrete was evaluated using analytical techniques. For this purpose, two concrete mixes of different composition (one used as control) were prepared with a water-to-binder ratio of 0.45. The self-healing process was triggered by the introduction in the concrete mix of a commercial expansive admixture (calcium sulfo-aluminate), two dicarboxylic acids, and sodium carbonate salt. After 28 days curing in water, the specimens were artificially cracked (crack width ≤ 900 μm) and then again water-cured for further 60 days until self-healing occurred. The progress of self-healing was investigated with a stereomicroscope at 40, 50, and 60 days, after cracking, to identify the quality and the degree of the healing. The efficiency of the self-healing process was also evaluated using micro-Raman spectroscopy and X-ray micro-computed tomography. Significant reduction in the crack width was observed as a result of a calcite filling, generated during the self-healing process. In some cases (crack width < 400 μm), the crack was completely healed. The experimental methodology used provided new insights into the evolution of the self-healing phenomenon in concrete.

Surface modified halloysite nanotube enhanced imine-based epoxy composites with high self-healing efficiency and excellent mechanical properties

2021 ◽  
Vol 12 (37) ◽  
pp. 5342-5356
Author(s):  
Hao Jiang ◽  
Meng Cheng ◽  
Caijiao Ai ◽  
Fanjie Meng ◽  
Yizeng Mou ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Mechanical Properties ◽  
The Self ◽  
Epoxy Composites ◽  
Cross Linking ◽  
Schematic Diagram ◽  
Self Healing ◽  
Halloysite Nanotube ◽  
Healing Efficiency ◽  
Surface Modified

(a) Schematic diagram of the self-healing mechanism. (b) Illustration of the cross-linking effect and the internal molecular structure.

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