Author Archives: ningyanlab

New Article: Self-healable, recyclable, and mechanically robust vitrimer composite for high-performance triboelectric nanogenerators and self-powered wireless electronics

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A new article from Ning Yan’s lab has been published in Nano Energy written by Araz Rajabi-Abhari, Pandeng Li, Majid Haji Bagheri, Asif Abdullah Khan, Cheng Hao, Nicolas R. Tanguy, Dayan Ban, Longjiang Yu, and Ning Yan.

You can find the article here

Abstract

With growing concerns about sustainability, there has been significant research interest in fabricating triboelectric nanogenerators (TENGs) from materials capable of self-repair. Here, we presented a novel polyimine/graphite polypropylene (PI/GP) vitrimer composite as a tribo-positive material for harvesting biomechanical energy. The PI/GP exhibited mechanical robustness, self-healing properties after damage, and recyclability through physical or chemical methods. The GP provided a high dielectric constant, charge transport paths, and desirable surface roughness, resulting in an outstanding TENG performance at an optimized addition level of 30 wt% in the composite (PI/GP30). Under a force of 15 N and a frequency of 6 Hz, the PI/GP30 TENG generated a power density of 2571 mW/m². Moreover, a PI/GP30 TENG device with an area of 49 cm2 was able to generate a remarkable output voltage of nearly 1325 V, at a frequency of 6 Hz and under a vertical force of 15 N. Additionally, the PI/GP30 TENG device produced a peak-to-peak voltage of 1250 V, and an outstanding current of around 2 mA by hand tapping with a force of 35–40 N. The PI/GP30 TENG was utilized for real-life applications, including a triboelectric watchband for a self-powered watch, and wireless data transmission. Furthermore, the PI/GP30 TENG demonstrated excellent self-healing and recyclability, and these properties were examined in a mousepad power generator. This study highlights the excellent promise of PI/GP vitrimer composite for fabricating high-performance, mechanically robust, self-healable, and recyclable TENGs, enabling their applications in green biomechanical power generators and wearable and wireless communication devices.

New Article: Mechanical and Insulation Performance of Rigid Polyurethane Foam Reinforced with Lignin-Containing Nanocellulose Fibrils

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A new article from Ning Yan’s lab has been published in Polymers written by Kabirat O. Bello and Ning Yan. 

You can find the article here.


Abstract

Isocyanates are critical components that affect the crosslinking density and structure of polyurethane (PU) foams. However, due to the cost and hazardous nature of the precursor for isocyanate synthesis, there is growing interest in reducing their usage in polyurethane foam production—especially in rigid PU foams (RPUF) where isocyanate is used in excess of the stoichiometric ratio. In this study, lignin-containing nanocellulose fibrils (LCNF) were explored as mechanical reinforcements for RPUF with the goal of maintaining the mechanical performance of the foam while using less isocyanate. Different amounts of LCNF (0–0.2 wt.%) were added to the RPUF made using isocyanate indices of 1.1, 1.05, 1.0, and 0.95. Results showed that LCNF served as a nucleating agent, significantly reducing cell size and thermal conductivity. LCNF addition increased the crosslinking density of RPUF, leading to enhanced compressive properties at an optimal loading of 0.1 wt.% compared to unreinforced foams at the same isocyanate index. Furthermore, at the optimal loading, LCNF-reinforced foams made at lower isocyanate indices showed comparable stiffness and strength to unreinforced foams made at higher isocyanate indices. These results highlight the reinforcing potential of LCNF in rigid polyurethane foams to improve insulation and mechanical performance with lower isocyanate usage.

Thank you Professor Zhaohui (Jolene) Tong for your visit

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On Friday July 19th, Professor Tong from Georgia Tech University paid a visit and gave a talk about the various work being done in the Tong Lab.

Dr. Tong has been an Associate Professor and James C. Barber Faculty Fellow in the School of Chemical and Biomolecular Engineering at Georgia Tech since January 2022. She is also the initiative leader in waste valorization in the food-water-energy nexus of the Renewable Bioproduct Institute (RBI). Previously, she served as an assistant and associate professor since 2010 at the University of Florida. She earned her Ph.D. in chemical engineering from Georgia Tech in 2007, followed by work at Ch2M Hill until 2009. Tong’s research focuses on synthesizing functional sustainable materials and catalytical conversion for biochemicals and biofuels from renewable resources. She has published 73 journal papers and 4 patents. Her research has been supported by NSF, USDA, NAS, and DOE. She secured about $5 million in grants after joining Georgia Tech in 2022. Dr. Tong has also served as an associate editor for three journals and held leadership roles in AIChE.

Her talk is summarized below:

Self-assembly of Multiple Functional Biomaterials for Food-Water-Energy Nexus
Bioresource materials such as cellulose, chitin, and lignin, are usually low-cost,
biocompatible, and abundant in nature. The synthesis of functional materials from these
bioresource materials can address long-term challenges in Food-water-Energy Nexus, such as resource and energy depletion, food security, water scarcity, and climate change. However, the adaption of chemical functionalization and self-assembling methodologies to renewable resource materials for functional materials is very challenging due to their macromolecular structures, heterogeneous properties, poor solubility, and the disturbance of impurities. In this talk, we will summarize how we explore self-assembly methods to produce new nanostructures and endure new functions for renewable resource materials. Several examples will be discussed. For example, glycerol, a biowaste from the biodiesel process, has been assembled into a nano-core-shell structure for a smart food packaging film sensor for universal real-time food spoilage monitoring. Biomass waste or cellulose can be assembled as multiple-function controlled-release fertilizers and smart membranes. Ultimately, we would like to use these self-assembly nanostructures from renewable resources to achieve a high-efficiency circular bioeconomy.

Thank you for your informative visit Professor Tong!

New Article: Lignin-based adaptable covalently cross-linked fabric for flexible sensors

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A new article out of a collaboration between Dr. Ning Yan and Dr. Jing Chen’s labs has been published in Materials Chemistry Frontiers written by Xiaozhen Ma, Xiaolin Wang, Honglong Zhao, Minghui Cui, Xiaobo Xu, Fangfang Kong, Peng Chen, Ning Yan, Jin Zhu and Jing Chen.

You can find the article here

Abstract

In this study, we successfully upcycled a novel lignin-based covalent adaptable polyurethane elastomer (LPUE) that we previously synthesized into a graphene-composited covalent adaptable lignin-based polyurethane fabric (LPUF). This fabric exhibited outstanding solvent resistance, toughness (LPUF-0 with a tensile strength of 29.1 ± 1.6 MPa, an elongation at break of 653 ± 67%, and a toughness of 103 ± 3.8 mJ m−3), and deformation responsiveness. These results not only open up new possibilities for improving covalently adaptable networks in fabrics, but also pave the way for developing solvent-resistant, wearable sensing devices.

New Article: A new 3D printing strategy by enhancing shear-induced alignment of gelled nanomaterial inks resulting in stronger and ductile cellulose films

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A new article out of a collaboration between Professor Ning Yan and Dr. Dan Li has been published in the Carbohydrate Polymers Journal written by Yunxia Yang, Dan Li, Ning Yan and Fu Guo.

You can find the article here

Abstract

Cellulose nanofibrils (CNFs) are derived from biomass and have significant potential as fossil-based plastic alternatives used in disposable electronics. Controlling the nanostructure of fibrils is the key to obtaining strong mechanical properties and high optical transparency. Vacuum filtration is usually used to prepare the CNFs film in the literature; however, such a process cannot control the structure of the CNFs film, which limits the transparency and mechanical strength of the film. Here, direct ink writing (DIW), a pressure-controlled extrusion process, is proposed to fabricate the CNFs film, which can significantly harness the alignment of fibrils by exerting shear stress force on the filaments. The printed films by DIW have a compact structure, and the degree of fibril alignment quantified by the small angle X-ray diffraction (SAXS) increases by 24 % compared to the vacuum filtration process. Such a process favors the establishment of the chemical bond (or interaction) between molecules, therefore leading to considerably high tensile strength (245 ± 8 MPa), elongation at break (2.2 ± 0.5 %), and good transparency. Thus, proposed DIW provides a new strategy for fabricating aligned CNFs films in a controlled manner with tunable macroscale properties. Moreover, this work provides theoretical guidance for employing CNFs as structural and reinforcing materials to design disposable electronics.

Welcoming a new addition

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Today we’d like to welcome the newest future scientist in the world, our PhD candidate Kabirat’s new son Rayyan.

Congratulations to Kabirat and her family! We are happy to see your family grow. 🥰

New Article: Degradable and Biobased Covalent Adaptable Networks for Light Controllable Switch

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A new article out of a collaboration between Dr. Ning Yan and Dr. Jing Chen’s labs has been published in the ACS Sustainable Chemistry & Engineering written by Xiaozhen Ma, Xiaolin Wang, Honglong Zhao, Minghui Cui, Xiaobo Xu, Fangfang Kong, Peng Chen, Ning Yan, Jin Zhu and Jing Chen.

You can find the article here

Abstract

In this study, we successfully synthesized lignin-based covalent adaptable polyurethane networks containing lignin-graphite nanosheet composite particles with a light controllable positive temperature coefficient (LPTC) effect. The use of lignin facilitated the direct exfoliation of graphite, thus overcoming the challenge of achieving a uniform dispersion of conductive fillers in the polymer matrix. The exfoliated graphite had a thickness of approximately 3.0 nm, which was equivalent to three to five layers of graphene. By preparing lignin-based covalent adaptable polyurethane without graphite composite particles (LPU) and lignin-based covalent adaptable polyurethane with graphite composite particles (LPU-G), we achieved remoldable properties and a high LPTC intensity for LPU-G. LPU-60G (60 represents the mass fraction of lignin-graphite nanosheets in polyols) exhibited an excellent LPTC effect, with sharp increases in resistance under light, particularly under near-infrared light (NIR), enabling the control of the current in circuits. Additionally, both LPU and LPU-G demonstrated degradability by slowly degrading in a PBS solution while rapidly degrading in an alkaline solution. Overall, the LPU-G synthesized in this study displayed superior stability in the LPTC effect and possessed degradability, providing a promising avenue for the future development of smart materials.

New Article: Robust and ultra-tough lignocellulosic organogel with zipper-like sliding noncovalent nanostructural design: Towards next-generation bio-derived flexible electronics

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A new article from Ning Yan’s lab has been published in Chemical Engineering Journal written by Haonan Zhang, Yanchen Zhu, Tongtong Fu, Cheng Hao, Yang Huang, Hao Ren, Ning Yan, Huamin Zhai. You can find the article HERE.

Click here to see the full article until April 25, 2024

Abstract

Soft electronics have garnered significant interests owing to their distinctive qualities. However, their practical utilizations are still limited by their generally poor mechanical properties, environmental concerns, and incompatibility. Here, we present a unique hierarchical nanoarchitectural design of dynamic noncovalent supramolecular zipper to achieve synergistic enhancement of both mechanical strength and toughness in organogels. By building lignin-carbohydrate complexes nanoparticles (LCCNPs)-based sliding zippers within the interpenetrating polymer networks (IPN) formed by in-situ regenerated cellulose nanofibrils (CNFs) and polyvinyl alcohol (PVA) molecular chains, the lignocellulosic organogels demonstrated excellent mechanical properties, shape recovery performances, and strain-stiffening behaviors. The ultimate tensile strength increased by 11-fold, reaching 8.29 MPa, while the toughness also had an increase of 24-fold, reaching 23.8 MJ/m3 at the same time, comparing to those of the PVA hydrogel. These novel organogels also exhibited exceptional anti-freezing (<-150 °C), anti-dehydration, transparency, UV-shielding, and biodegradable properties. The assembled wearable sensor using the organogels were able to monitor human motion status and physiological signals with a tunable conductivity (up to 5.14 S/m), a high sensitivity (a maximum gauge factor of 5.62) and long cyclic stability (2000 cycles). This novel nano-structural design approach showcases a facile and versatile platform for constructing the next-generation high performance bio-based soft electronics.