Article
Energy & Fuels
Chang Cong, Jixiao Wang, Guangyu Xing, Zhan Wang, Sicheng Yuan, Zhi Wang
Summary: Polymeric coatings used in outdoor applications, such as solar energy collection and metal protection, suffer from short service life. This study developed a composite coating of oxidized carbon black (OCB) and epoxy vitrimer (EV) through a solvent mixing method. The addition of OCB improved stress relaxation rate and provided high solar absorptance and solar thermal efficiency. The composite coating showed high healing efficiency for micro scratches and novel photothermal patching for macroscopic damage. The coating also exhibited shape memory, reusability, and ion transfer barrier performance. Overall, the OCB/EV composite coating has potential applications in solar energy harvesting and offers a new strategy for the repair of polymeric coatings used in outdoor applications.
SOLAR ENERGY MATERIALS AND SOLAR CELLS
(2023)
Article
Materials Science, Characterization & Testing
Amber M. Hubbard, Yixin Ren, Alireza Sarvestani, Catalin R. Picu, Vikas Varshney, Dhriti Nepal
Summary: Vitrimers are a new generation of polymer materials combining the strength of traditional thermoset polymers with the reprocessability of traditional thermoplastic polymers. This study validates thermomechanical analysis (TMA) as a reliable method for identifying the vitrimer topology freezing temperature (Tv) and demonstrates the value of TMA in Tv identification by validating accepted trends in the literature.
Article
Engineering, Environmental
Picheng Chen, Yu Ding, Yanqing Wang, Hongzhe Zhao, Pengcheng Li, Yuetao Liu, Chuanhui Gao
Summary: In this study, a new regulatory strategy using conjugated structures and functional compounds was proposed to enhance the toughness and stability of vitrimers. The design of crosslinking points was optimized to lower the energy barrier for imine bond exchange, which accelerated the exchange rate of covalent bonds. By increasing the crosslinking density, the vitrimer exhibited increased strain under external forces. Additionally, the synthesized vitrimer showed excellent welding, healing, and shape memory performance.
CHEMICAL ENGINEERING JOURNAL
(2023)
Article
Materials Science, Composites
Bhashkar Singh Bohra, Poonam Singh, Anita Rana, Harsh Sharma, Tanuja Arya, Mayank Pathak, Alok Chaurasia, Sravendra Rana, Nanda Gopal Sahoo
Summary: This study utilized covalent functionalization to modify graphene oxide (GO) with 4-aminophenyl disulfide (4-AFD) for the development of vitrimer epoxy nanocomposites. The functionalization of GO was confirmed through FT-IR, Raman, and XRD analyses, as well as TEM and elemental analysis. The dispersion of GO and FGO inside the polymer matrix was examined using FE-SEM, showing improved dispersion due to the functionalization of GO.
COMPOSITES SCIENCE AND TECHNOLOGY
(2023)
Article
Engineering, Manufacturing
Henri Perrin, Regis Vaudemont, Doriane Del Frari, Pierre Verge, Laura Puchot, Masoud Bodaghi
Summary: This study investigates the self-healing capability of a novel bio-based benzoxazine vitrimer composite laminate. The laminate is manufactured using compression resin transfer moulding, and three-point bending tests are conducted to assess interlaminar shear strength (ILSS) and induced damage. Interfacial damages are healed through pressure and temperature. The results show that the composite has highly efficient healing capability, with 80% of the ILSS restored after a 60-minute healing process.
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2024)
Article
Nanoscience & Nanotechnology
Xiling Niu, Min Wang, Yifan Xia, Yan Zhu, Xiaoyong Jia, Ruirui Cao, Xin Wang
Summary: A novel dual-cross-linked polymer was synthesized via a facile method and used to construct a shape memory nanogenerator. The thermomechanical and stress relaxation performances of the polymer can be customized by tuning the proportion of cross-linking knots. It demonstrates distinctive performance and tunable electrical outputs.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
Yang Yang, Huimin Wang, Shuai Zhang, Yen Wei, Xiangming He, Jianlong Wang, Yingying Zhang, Yan Ji
Summary: Soft actuators with multi-stimuli response and multichannel self-healing ability are rare in current research. This study demonstrated the development of a thermosetting soft actuator through hot-pressing carbonized silk fabrics onto vitrimers, allowing efficient and repeatable self-healing by five stimuli and simultaneous response to four stimuli. The nature of vitrimer makes the actuator robust, sustainable, recyclable, and reprocessable, broadening its potential applications.
Article
Chemistry, Physical
Jian Li, Jinsheng Sun, Kaihe Lv, Yuxi Ji, Xianbin Huang, Yingrui Bai, Jintang Wang, Jiafeng Jin, Shenglong Shi, Jingping Liu
Summary: This study introduces a novel concept of PU vitrimers with self-healing and recyclability properties, along with enhanced mechanical performance through multiple crosslinking strategies. By incorporating dynamic covalent and non-covalent bonds, the comprehensive enhancement of PUs for various industrial applications is achieved.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Materials Science, Composites
Lingyun Huang, Yinxin Yang, Zhen Niu, Ruiyao Wu, Weifeng Fan, Quanquan Dai, Jianyun He, Chenxi Bai
Summary: This study demonstrates a simple and general strategy to construct covalent adaptable networks with self-healing, shape memory, and recyclability in elastomers, showing great potential in the development of rubber-based vitrimer elastomers and flexible wearable devices with high stretchability and tensile strength. The materials can be recovered by hot pressing or dissolution, while the recovered sample remains unchanged, and a self-healing flexible electronic device can be fabricated using these elastomers.
COMPOSITES SCIENCE AND TECHNOLOGY
(2022)
Article
Engineering, Multidisciplinary
Yun Hu, Puyou Jia, Meghan E. Lamm, Ye Sha, Leman Buzoglu Kurnaz, Yufeng Ma, Yonghong Zhou
Summary: This study reports the direct construction of bio-based epoxy vitrimers (EVs) from renewable resources, such as soybean oil and tung oil, which exhibit multi-stimuli responsiveness and multichannel self-healing ability. The EVs showed increased tensile strength due to the formation of multiple H-bonds and increased crosslink density. The EVs with micropores or cracks achieved self-healing after heating at 200 degrees C, and a strategy for fabricating full plant oil-based EV composites using graphene was developed to achieve self-healing triggered by multiple stimuli.
COMPOSITES PART B-ENGINEERING
(2023)
Article
Engineering, Electrical & Electronic
Shichang Luo, Yunlong Ma, Xinlei Wei, Yinghua Jin, Li Qiu, Wei Zhang
Summary: This work presents a flexible conductive composite based on graphene aerogel and polyimine vitrimer, with good mechanical properties and high electrical conductivity, suitable for flexible electronic applications. Its recyclability enables the recovery and reuse of electronic waste, reducing environmental impact.
ACS APPLIED ELECTRONIC MATERIALS
(2021)
Article
Chemistry, Applied
Chang Cong, Jixiao Wang, Zhan Wang, Guangyu Xing, Zhi Wang
Summary: In this study, a room-temperature brushable oxidized carbon black (OCB)/epoxy vitrimer composite with dynamic transesterification reaction was prepared by solvent method. The composite exhibited excellent protective performance and localized photothermal-healing ability. No external catalysts, preheating, and hot press were required in the preparation process. The results showed that the composite coatings had outstanding metal protective performance. Effective non-contact local photothermal-healing could be achieved within 20 minutes, with the scratch width narrowing over 95% and the impedance moduli of the coatings recovering from 263Ω.cm² to above 108Ω.cm². The OCB/epoxy vitrimer composite coating, combining ideal metal protective performance with non-contact local photothermal-healing, has great potential for practical applications such as metal protection and solar-energy collector.
PROGRESS IN ORGANIC COATINGS
(2023)
Article
Instruments & Instrumentation
John Konlan, Xiaming Feng, Guoqiang Li
Summary: Damage healing in fiber reinforced thermoset polymer composites can be achieved through intrinsic healing of the polymer itself or extrinsic healing by incorporating external healing agent. In this study, a hybrid extrinsic-intrinsic self-healing strategy was proposed to heal delamination in laminated thermoset polymer composites induced by low velocity impact. By using a novel vitrimer powder as the external healing agent, the laminate exhibited multifunctionalities including repeated delamination healing, excellent shape memory effect, improved toughness and impact tolerance, and decent fire-proof properties. The results showed high delamination healing efficiencies and recovery stress, indicating great potential in various engineering applications.
SMART MATERIALS AND STRUCTURES
(2023)
Article
Chemistry, Multidisciplinary
Xinxin Yang, Shibo Wang, Xiuxiu Liu, Zhen Huang, Xujuan Huang, Xu Xu, He Liu, Dan Wang, Shibin Shang
Summary: A NIPU with a dual dynamic network was designed in this study to achieve reprocessing and self-healing under mild conditions.
Article
Engineering, Environmental
Yazhou Xu, Songlin Dai, Liangwu Bi, Jianxin Jiang, Haibo Zhang, Yuxiang Chen
Summary: A degradable Epoxidized menthane diamine-adipic acid (EMDA-AA) vitrimer matrix was developed for Carbon fiber reinforced composites (CFRPs), which addresses the over-reliance on petroleum-based products and difficult recycling of Carbon fibers (CFs). The vitrimer matrix showed good mechanical properties and the ability to achieve topological rearrangement without additional catalysts, allowing for self-healing, shape memory, and efficient recycling of CFs. This study provides a strategy for preparing green and high-strength CFRPs using recyclable bio-based epoxy vitrimer matrices.
CHEMICAL ENGINEERING JOURNAL
(2022)
Article
Chemistry, Multidisciplinary
Dhriti Nepal, W. Joshua Kennedy, Ruth Pachter, Richard A. Vaia
Summary: Achieving a combination of excellent EMI shielding, transparency, and mechanical robustness requires precision engineering of hierarchical structures, which can be inspired by nature's diverse combination of properties in synthetic architected nanocomposites.
Article
Chemistry, Multidisciplinary
James E. Heckler, Gregory R. Neher, Faisal Mehmood, David B. Lioi, Ruth Pachter, Richard Vaia, W. Joshua Kennedy, Dhriti Nepal
Summary: The study introduces a method of functionalizing MXene nanosheets with catechols, which can increase the interlayer spacing and bind to the surface through metal-oxygen bonds. The results demonstrate that this strategy can modify the colloidal stability of MXene surfaces and introduce more functionality, providing excellent anchoring points for growing polymer brushes and tuning specific properties.
Article
Chemistry, Physical
Gary S. Kedziora, James Moller, Rajiv Berry, Dhriti Nepal
Summary: Ab initio molecular dynamics were employed to investigate the response of polyethylene and radical chains to constant imposed strain. The study revealed the impact of strain on bond breaking process by computing the free energy under different strain conditions.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Nanoscience & Nanotechnology
Katarina Adstedt, Filip Stojcevski, Ben Newman, David J. Hayne, Luke C. Henderson, David Mollenhauer, Dhriti Nepal, Vladimir Tsukruk
Summary: The surface topography of carbon fibers and their composites plays a crucial role in determining their ultimate properties. However, there is limited research on the nanoscale surface characteristics of carbon fibers and their relationship with chemical modification. In this study, high-resolution atomic force microscopy was used to investigate the nanoscale surface topography of modified carbon fibers, revealing the influence of tension and chemical functionalization on the surface characteristics and their impact on interfacial interactions.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Chemistry, Multidisciplinary
Minkyu Kim, Kellina Pierce, Michelle Krecker, Daria Bukharina, Katarina Adstedt, Dhriti Nepal, Timothy Bunning, Vladimir V. Tsukruk
Summary: Bioenabled crack-free chiral nematic films were successfully prepared using cellulose nanocrystals (CNCs) in a capillary confinement with specific modifications. The modified CNC/TOPA/PEG films demonstrated improved mechanical performance, consistent vivid iridescence, and enhanced circular polarization. The addition of a small amount of TOPA proved to be crucial in achieving the best performance in preventing cracks.
Article
Polymer Science
Camaryn Bennett, Peter J. Hayes, Carl J. Thrasher, Progyateg Chakma, Shiwanka Wanasinghe, Borui Zhang, Leilah M. Petit, Vikas Varshney, Dhriti Nepal, Alireza Sarvestani, Catalin R. Picu, Jessica L. Sparks, Mehdi B. Zanjani, Dominik Konkolewicz
Summary: The hyperelastic models developed by Gent, Ogden, and Dobrynin have been modified to incorporate a strain rate-dependent element, allowing for a better understanding of the breaking behavior of temporary bonds in materials. These modified models were tested on a wide range of elastomeric materials and found to be applicable to various network polymers. Template spreadsheets have also been provided, facilitating the application of these models to complex soft materials.
Article
Materials Science, Multidisciplinary
Amber M. Hubbard, Yixin Ren, Catalin R. Picu, Alireza Sarvestani, Dominik Konkolewicz, Ajit K. Roy, Vikas Varshney, Dhriti Nepal
Summary: This article discusses the creep mechanics of epoxy vitrimers, identifying three distinct creep regimes and quantifying the correlations between creep and factors such as temperature, catalyst concentration, and heating rate.
ACS APPLIED POLYMER MATERIALS
(2022)
Article
Chemistry, Multidisciplinary
Amber M. Hubbard, Yixin Ren, Alireza Sarvestani, Dominik Konkolewicz, Catalin R. Picu, Ajit K. Roy, Vikas Varshney, Dhriti Nepal
Summary: With the focus on sustainability in material research, recyclable polymers like vitrimers have gained attention for their self-healing, shape memory, and shape reconfigurability properties. The study analyzes the influence of processing conditions on the material's performance and highlights the trade-off between recovery performance and material degradation. It emphasizes the importance of understanding how experimental parameters impact the properties, stability, and reprocessability of vitrimers before they can reach their full potential.
Review
Chemistry, Physical
Dhriti Nepal, Saewon Kang, Katarina M. Adstedt, Krishan Kanhaiya, Michael R. Bockstaller, L. Catherine Brinson, Markus J. Buehler, Peter Coveney, Kaushik Dayal, Jaafar A. El-Awady, Luke C. Henderson, David L. Kaplan, Sinan Keten, Nicholas A. Kotov, George C. Schatz, Silvia Vignolini, Fritz Vollrath, Yusu Wang, Boris Yakobson, Vladimir V. Tsukruk, Hendrik Heinz
Summary: This Review discusses recent advancements in bioinspired nanocomposite design, focusing on the role of hierarchical structuring at different length scales in creating multifunctional, lightweight, and robust structural materials. By manipulating the architecture, interphases, and confinement, dynamic and synergistic responses have been achieved. The study highlights the significance of hierarchical structures across multiple length scales for achieving multifunctionality and robustness.
Article
Materials Science, Characterization & Testing
Amber M. Hubbard, Yixin Ren, Alireza Sarvestani, Catalin R. Picu, Vikas Varshney, Dhriti Nepal
Summary: Vitrimers are a new generation of polymer materials combining the strength of traditional thermoset polymers with the reprocessability of traditional thermoplastic polymers. This study validates thermomechanical analysis (TMA) as a reliable method for identifying the vitrimer topology freezing temperature (Tv) and demonstrates the value of TMA in Tv identification by validating accepted trends in the literature.
Article
Materials Science, Multidisciplinary
Amber M. Hubbard, Yixin Ren, Dominik Konkolewicz, Alireza Sarvestani, Catalin R. Picu, Gary S. Kedziora, Ajit Roy, Vikas Varshney, Dhriti Nepal
Summary: The study introduces unique data interpretation methods to achieve excellent agreement between different T-v measurement methodologies for vitrimers. Experimental parameters and catalyst concentration play crucial roles in determining the T-v range, with the T-v value being temperature-dependent.
ACS APPLIED POLYMER MATERIALS
(2021)
Article
Nanoscience & Nanotechnology
Yixin Ren, Rahul Rao, Shusil Bhusal, Vikas Varshney, Gary Kedziora, Robert Wheeler, Youngjong Kang, Ajit Roy, Dhriti Nepal
ACS APPLIED NANO MATERIALS
(2020)
