Author Archives: ningyanlab

New Article: Gradient-Layered MXene/Hollow Lignin Nanospheres Architecture Design for Flexible and Stretchable Supercapacitors

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A new article from Ning Yan’s lab has been published in Nano-Micro Letters written by Haonan Zhang, Cheng Hao, Tongtong Fu, Dian Yu, Jane Howe, Kaiwen Chen, Ning Yan, Hao Ren and Huamin Zhai.

You can find the article here

Abstract

With the rapid development of flexible wearable electronics, the demand for stretchable energy storage devices has surged. In this work, a novel gradient-layered architecture was design based on single-pore hollow lignin nanospheres (HLNPs)-intercalated two-dimensional transition metal carbide (Ti3C2Tx MXene) for fabricating highly stretchable and durable supercapacitors. By depositing and inserting HLNPs in the MXene layers with a bottom-up decreasing gradient, a multilayered porous MXene structure with smooth ion channels was constructed by reducing the overstacking of MXene lamella. Moreover, the micro-chamber architecture of thin-walled lignin nanospheres effectively extended the contact area between lignin and MXene to improve ion and electron accessibility, thus better utilizing the pseudocapacitive property of lignin. All these strategies effectively enhanced the capacitive performance of the electrodes. In addition, HLNPs, which acted as a protective phase for MXene layer, enhanced mechanical properties of the wrinkled stretchable electrodes by releasing stress through slip and deformation during the stretch-release cycling and greatly improved the structural integrity and capacitive stability of the electrodes. Flexible electrodes and symmetric flexible all-solid-state supercapacitors capable of enduring 600% uniaxial tensile strain were developed with high specific capacitances of 1273 mF cm−2 (241 F g−1) and 514 mF cm−2 (95 F g−1), respectively. Moreover, their capacitances were well preserved after 1000 times of 600% stretch-release cycling. This study showcased new possibilities of incorporating biobased lignin nanospheres in energy storage devices to fabricate stretchable devices leveraging synergies among various two-dimensional nanomaterials.

New Article: Catalyst-Free Biodegradable Chitosan-Based Dual Dynamic Covalent Networks with Self-Healing and Flame-Retardant Properties

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A new article from Ning Yan’s lab has been published in ACS Sustainable Chemistry & Engineering written by Mohammad H. Mahaninia and Ning Yan.

You can find the article here

Abstract

Synthesizing covalent adaptable networks (CANs) from chitosan has been difficult due to its inherent insolubility in organic solvents. In this study, we report a facile approach for obtaining biobased flame-retarding CANs using chitosan as the starting material without dissolving it. These novel CANs were prepared via a dual cross-linking strategy in which chitosan consecutively reacted with citric acid and a vanillin-based cross-linker containing a flame-retarding moiety. The chitosan-based CANs attained dual dynamic bond-exchange sites resulting from generation of amide and ester linkages, which enabled them to perform self-healing and recyclability. They also possessed remarkable flame-retarding performance (e.g., limiting oxygen index of 41.5% and UL-94 V-0 rating), surpassing other chitosan-based flame retardants reported in the literature to date. By investigating the CAN’s response to fire in both gas and condensed phases, their flame-retarding mechanisms were uncovered. This study pinpoints a promising approach to make biobased, biodegradable, and multifunctional CANs from chitosan.

Ning Yan Lab Presents at Canadian Chemical Engineering Conference in Toronto

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Five group members from Professor Ning Yan’s lab including Haonan Zhang, Cheng Hao, Nicole Tratnik, Araz Rajabi and Mohammad Mahaninia, showcased their work at the Canadian Chemical Engineering Conference (CSChE 2024) in Toronto from October 6th to October 9th.
At this four day conference the work of Professor Yan’s group was presented among many successful chemical engineers from across the country.

CPI Travel Honoraria Awarded for Research Presentation at the 2024 Polyurethanes Conference

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Ph.D Candidate, Kabirat Bello, was awarded the CPI Travel Honoraria to present
her research at the 2024 Polyurethanes Conference in Atlanta, Georgia. Her
presentation was titled, “Exploring Lignin-Containing Nanocellulose Fibrils
(LCNFs) for Enhancing Mechanical and Thermal Insulation Performance of Rigid
Polyurethane Foams”.
Congrats Kabirat!

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.