Sandwich-like polyvinyl alcohol (PVA) grafted graphene: A solid-inhibitors container for long term self-healing coatings

2020 ◽  
Vol 383 ◽  
pp. 123203 ◽  
Author(s):  
Yunan Lin ◽  
Rongrong Chen ◽  
Yanjun Zhang ◽  
Zhu Lin ◽  
Qi Liu ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Self Healing

scholarly journals Feasibility of Using 3D Printed Polyvinyl Alcohol (PVA) for Creating Self-Healing Vascular Tunnels in Cement System

Materials ◽  
2019 ◽  
Vol 12 (23) ◽  
pp. 3872 ◽  
Author(s):  
Zijing Li ◽  
Lívia Ribeiro de Souza ◽  
Chrysoula Litina ◽  
Athina E. Markaki ◽  
Abir Al-Tabbaa
Keyword(s):  
Polyvinyl Alcohol ◽  
Early Stage ◽  
Cementitious Materials ◽  
Self Healing ◽  
Vascular Networks ◽  
X Ray Diffraction ◽  
Cement Pastes ◽  
Polymer Compound ◽  
3D Printed

Pursuing long-term self-healing infrastructures has gained popularity in the construction field. Vascular networks have the potential to achieve long-term self-healing in cementitious infrastructures. To avoid further monitoring of non-cementitious tubes, sacrificial material can be used as a way of creating hollow channels. In this research, we report a new method for fabrication of complex 3D internal hollow tunnels using 3D printing of polyvinyl alcohol (PVA). The behaviour of 3D printed PVA structures in cement pastes was investigated using computed-tomography (CT) combined with X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy with energy dispersive spectroscopy (SEM/EDX). Results showed that (i) 1300 min were needed to fully dissolve 1 g of a 3D printed PVA structure, and different pH solutions did not significantly change the PVA dissolving process compared with a neutral environment; (ii) a low water/cement ratio can minimize early stage cracking resulting from PVA expansion; (iii) and PVA-cement interaction products were mainly calcite and a Ca-polymer compound. In conclusion, controlling the PVA expansion by decreasing the water/cement (w/c) ratio provides a promising approach to achieve 3D hollow channels in cement and, therefore, makes it possible to create complex tunnels within self-healing cementitious materials.

Cohesion versus friction in controlling the long-term strength of a self-healing experimental fault

2016 ◽  
Vol 121 (12) ◽  
pp. 8523-8547 ◽  
Author(s):  
J. Weiss ◽  
V. Pellissier ◽  
D. Marsan ◽  
L. Arnaud ◽  
F. Renard
Keyword(s):  
Self Healing ◽  
Term Strength

Fast self-healing multifunctional polyvinyl alcohol nano-organic composite hydrogel as building blocks for highly sensitive strain/pressure sensors

2021 ◽  
Author(s):  
Wenhao Zhao ◽  
Dongzhi Zhang ◽  
Yan Yang ◽  
Chen Du ◽  
Bao Zhang
Keyword(s):  
Polyvinyl Alcohol ◽  
Human Computer Interaction ◽  
Pressure Sensors ◽  
Building Blocks ◽  
Composite Hydrogel ◽  
Sensitive Strain ◽  
Self Healing ◽  
Wearable Sensor ◽  
Hybrid Hydrogel ◽  
Highly Sensitive

The conductive and biocompatible hybrid hydrogel was successfully assembled into an adhesive, flexible wearable sensor for ultra-sensitive human-computer interaction and smart detection, which holds excellent self-healing capability. This conductive, repairable...

Application of self-healing, swellable and biodegradable polymers for wound treatment

2021 ◽  
Vol 30 (Sup9a) ◽  
pp. IVi-IVx
Author(s):  
Chukwuma O Agubata ◽  
Mary A Mbah ◽  
Paul A Akpa ◽  
Godwin Ugwu
Keyword(s):  
Wound Healing ◽  
Polyvinyl Alcohol ◽  
Biodegradable Polymers ◽  
Hydroxypropyl Methylcellulose ◽  
Composite Films ◽  
Self Healing ◽  
Moisture Uptake ◽  
Folding Endurance

Aim: Self-healing, swellable and biodegradable polymers are vital materials that may facilitate the different stages of wound healing. The aim of this research was to prepare wound healing films using self-healing polyvinyl alcohol (PVA), swellable hydroxypropyl methylcellulose (HPMC), biodegradable polyglycolic acid (PGA) sutures and ciprofloxacin antibiotic for improved treatment outcome. Methods: Films were formulated through aqueous-based mixing of varying amounts of polyvinyl alcohol (10–20% weight/weight (w/w)) and hydroxypropyl methylcellulose (0.5, 1% w/w) with fixed quantities of ciprofloxacin. PGA sutures were placed as grids within the wet mixtures of the polymers and ciprofloxacin, and thereafter products were air dried. The formulated films were evaluated for swelling ratio, breaking elongation, folding endurance, moisture uptake and loss, compatibility and in vitro antibiotic release. Furthermore, in vivo wound healing was studied using excision model and histopathological examinations. Results: Swelling ratios were above 1.0 and the films were minimally stretchable, with folding endurance greater than 500. Films were stable while moisture uptake and loss were observed to be less than 30%. Among the optimised hydrogel batches, those containing 10% w/w PVA and 1% w/w HPMC with no PGA showed the highest drug release of 73%, whereas the batches with higher PGA content showed higher percentage wound size reduction with minimal scar. The completeness of wound healing with batches containing PVA, HPMC, ciprofloxacin and PGA, along with the standard, is evident considering the massive cornification, regeneration of the epithelial front and stratum spinosum. Conclusion: The findings show that polymer-based multifunctional composite films are suitable for use as dressings for improved wound healing.

Self-Healing Superhydrophobic Materials Showing Quick Damage Recovery and Long-Term Durability

Langmuir ◽  
2017 ◽  
Vol 33 (38) ◽  
pp. 9972-9978 ◽  
Author(s):  
Liming Wang ◽  
Chihiro Urata ◽  
Tomoya Sato ◽  
Matt W. England ◽  
Atsushi Hozumi
Keyword(s):  
Self Healing

scholarly journals Characterization of polyvinyl alcohol-borax/agarose (PVA-B/AG) double network hydrogel utilized for the cleaning of works of art

2020 ◽  
Author(s):  
Ehab Awad Al-Emam ◽  
Hilde Soenen ◽  
Joost Caen ◽  
Koen Janssens
Keyword(s):  
Polyvinyl Alcohol ◽  
Self Healing ◽  
Retention Capacity ◽  
Structured Surfaces ◽  
Double Network ◽  
Liquid Retention ◽  
Long Time ◽  
Cleaning Procedures ◽  
Phase Retention

Abstract Since cleaning of artworks may cause undesirable physicochemical alterations and is a nonreversible procedure, it is mandatory to adopt the proper cleaning procedure. Such a procedure should remove undesired materials whilst preserving the original surface. In this regard, numerous gels have been developed and exploited for the cleaning of various artwork surfaces. Lately, agarose (AG) and polyvinyl alcohol-borax (PVA-B) hydrogels have been widely employed as cleaning tools by conservators. Both hydrogels show some limitations in specific cleaning practices. In this work, we investigated the influence of including increased levels of agarose into PVA-B systems. For this reason, we performed a detailed characterization on the double network (DN) hydrogel including the chemical structure, the liquid phase retention, the rheological behavior, and the self-healing behavior of various PVA-B/AG double network hydrogels. These new hydrogels revealed better properties than PVA-B hydrogels and obviated their limitations. The inclusion of AG into PVA-B systems enhanced the liquid retention capacity, shape-stability, and mechanical strength of the blend. Furthermore, AG minimized the expelling/syneresis issue that occurs when loading PVA-B systems with low polarity solvents or chelating agents. The resultant double network hydrogel exhibits relevant self-healing properties. The PVA-B/AG double network is a new and useful cleaning tool that can be added to the conservators’ tool-kit. It is ideal for cleaning procedures dealing with porous and complex structured surfaces, vertical surfaces and for long time applications.

Successful Remediation of Sustained Casing Pressures in Gas Cap Injector Wells with the Use of Flexible and Self Healing System

2021 ◽  
Author(s):  
Bipin Jain ◽  
Abhijeet Tambe ◽  
Dylan Waugh ◽  
Moises MunozRivera ◽  
Rianne Campbell
Keyword(s):  
Self Healing ◽  
Injection Wells ◽  
Coiled Tubing ◽  
Cement System ◽  
Sustained Casing Pressure ◽  
Casing Pressure ◽  
New Generation ◽  
Prudhoe Bay ◽  
Production Tubing

Abstract Several injection wells in Prudhoe Bay, Alaska exhibit sustained casing pressure (SCP) between the production tubing and the inner casing. The diagnostics on these wells have shown communication due to issues with casing leaks. Conventional cement systems have historically been used in coiled-tubing-delivered squeeze jobs to repair the leaks. However, even when these squeeze jobs are executed successfully, there is no guarantee in the short or long term that the annular communication is repaired. Many of these injector wells develop SCP in the range of 300-400 psi post-repair. It has been observed that the SCP development can reoccur immediately after annulus communication repair, or months to years after an injector well is put back on injection. Once SCP is developed the well cannot be operated further. A new generation of cement system was used to overcome the remedial challenge presented in these injector wells. This document provides the successful application of a specialized adaptive cement system conveyed to the problematic zone with the advantage of using coiled tubing equipment for optimum delivery of the remedial treatment.

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