Monthly Archives: May 2025

Seminar Announcement: Prof. Michael F. Cunningham (Queen’s University), Carbon Dioxide Responsive Polymers: Design, Properties, and Applications

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Carbon Dioxide Responsive Polymers: Design, Properties, and Applications

Carbon dioxide (CO₂) responsive polymers exhibit reversible property changes triggered by atmospheric-pressure CO₂, offering promising potential for various applications. These smart materials provide distinct advantages over conventional stimuli-responsive polymers, notably the use of CO₂ as a nontoxic, cost-effective, and environmentally benign trigger. This lecture will explore the molecular design of CO₂-switchable systems, focusing on polymers with tertiary amine and amidine functionalities. These materials undergo reversible transitions from hydrophobic to hydrophilic states via protonation and deprotonation, a mechanism that avoids accumulation of waste byproducts. Professor Cunningham will discuss key design considerations, such as functional group basicity and concentration, and their role in optimizing switching efficiency.  Practical implementations of these materials will be showcased, including switchable nanoparticles, viscosity modifiers, hydrogels, coatings, and surfaces. Applications range from smart coatings to forward osmosis water purification technologies, highlighting the versatility and real-world relevance of CO₂-responsive polymer systems.

When: June 10 @ 10:00 am

Where: Room WB215

Host: Prof. Ning Yan

Bio:

Professor Michael Cunningham holds the Donald and Sarah Munro Research Chair in Chemical Engineering at Queen’s University. His research focuses on polymer nanoparticle synthesis, CO₂-switchable polymers, and sustainable polymeric materials, especially those combining synthetic and bio-based components. He currently serves as Chair of the International Polymer Colloids Group and has received multiple prestigious awards, including the NSERC Brockhouse Canada Prize for Interdisciplinary Research, the Canadian Green Chemistry and Engineering Award, and the Macromolecular Science and Engineering Award. Dr. Cunningham is a Fellow of the Chemical Institute of Canada, the Canadian Academy of Engineering, and the Engineering Institute of Canada. He has made significant contributions to the field of polymer science, particularly in the development of environmentally responsive and sustainable materials.

OMNI Interviews Prof. Ning Yan: Exploring Sustainability

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OMNI recently interviewed Professor Ning Yan, focusing on sustainability and the innovative approaches driving environmental responsibility. In the discussion, Professor Yan shared insights on sustainable practices and advancements that contribute to a greener future.

She highlighted key developments in eco-friendly technologies, emphasizing the importance of scientific innovation in tackling global sustainability challenges. Her research offers valuable perspectives on creating solutions that reduce environmental impact while fostering long-term sustainability.

Check out the full interview to learn more about Professor Yan’s work and vision for a sustainable future.

New Article : Green, Sustainable, and Melt-Compoundable PLA Composites Reinforced with Spray-Dried Lignocellulosic Nanofibrils for Enhanced Barrier and Mechanical Properties

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A new article from Ning Yan’s lab has been published in Chemical Engineering Journal written by To Yu Troy Su, Rafaela Aguiar, Nello D. Sansone, Cheng Hao, Ning Yan, and Patrick C. Lee.

You can find the paper here.

Abstract

This study presents the first integration of spray dried (SD), non-modified, lignocellulosic nanofibrils (LCNF) into polylactic acid (PLA) by melt blending. Originating from industrial forestry waste, SD LCNFs are an inexpensive, non-toxic, and abundantly accessible drop-in filler whose production is facile, continuous, and highly scalable. Addition of SD LCNF into PLA yields enhanced barrier and mechanical performance due to SD LCNF’s alteration of the crystalline microstructure and fracture dynamics. Incorporating 1–1.5 wt% of SD LCNFs into PLA results in significant enhancements: tensile strength by 32.8%, toughness by 44.6%, water vapor barrier performance by 38.8%, and oxygen barrier properties by 26.4%, compared to neat PLA. Their nucleating capability hastens isothermal crystallization of PLA composites by over 90%, enabling faster processing times. For the first time, in-situ polarized optical microscopy is used to visualize fracture toughening mechanisms in PLA under strain, revealing a direct link between mechanical property improvements and the role of SD LCNFs as craze nucleators in PLA. Additionally, the in-situ observation of crystallization kinetics highlights how SD LCNFs influences PLA microstructure, correlating these structural changes with enhanced barrier and mechanical properties. The composite’s optical clarity and UV shielding capabilities are assessed, confirming its potential for specialty packaging applications.

New Article: Bioinspired wood-based wedge-shaped surface with gradient wettability for enhanced directional liquid transport and fog harvesting

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A new article from Ning Yan’s lab has been published in Materials Horizens written by Kaiwen Chen, Luyao Chen, Xianfu Xiao, Cheng Hao, Haonan Zhang, Tongtong Fu, Wei Shang, Hui Peng, Tianyi Zhan, Jianxiong Lyu and Ning Yan.

You can find the article here.

Abstract
Inspired by cactus spine and desert beetle back structures, we developed a wood-based wedge-shaped surface with gradient wettability for efficient and controlled spontaneous directional liquid transport. Utilizing the natural anisotropic and porous structure of wood, the wedge-shaped surface exhibited a continuous gradient wettability after chemical treatments combined with UV-induced modifications. The resulting surface enabled highly efficient directional liquid transport with transport rates reaching up to 8.9 mm s−1 on horizontal placement and 0.64 mm s−1 on vertical surfaces against gravity. By integrating geometric curvature and surface energy gradients, the innovative design achieved synergistic Laplace pressure-driven and wettability-driven liquid motions. To further demonstrate its potential for practical application, a fog-driven power device constructed using the gradient wettability wood with cactus spines not only enhanced water harvesting and energy conversion capabilities but also offered an environmentally friendly system. This study expanded the design toolbox for bioinspired liquid management surfaces, offering promising applications in water resource management, energy harvesting, and microfluidic devices.

New Article: Preparing Flexible, Ductile, and Transparent Lignocellulose Composite Films via a Chemical (Betaine) and Mechanical (3D Printing) Combined Approach

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A new article from Ning Yan’s lab in collaboration with Dan Li has been published in ACS Sustainable Chemistry & Engineering written by Yunxia Yang, Dan Li, Ning Yan and Fu Guo.

You can find the article here

Abstract Image

Abstract

Developing highly mechanically resilient and transparent cellulose films is critical for use in next-generation degradable electronics. The use of synthetic plasticizers and additives is a detour that impairs the biocompatibility and biodegradability of the final product. This study utilized betaine, which can be easily obtained from vegetables, in preparing flexible, ductile, and highly transparent lignocellulose nanofibrils (LCNFs) films through direct ink writing (DIW). An optimum 40 wt % betaine content of dry LCNFs endowed the films with outstanding optical transmittance (87%) at 800 nm. The maximum elongation at break of the betaine-containing lignocellulose nanofibril (LCNFsB) film reached 13.9 ± 0.5%, representing a 309% increase compared to the plain LCNFs film. We systematically investigated the shear-induced alignment between the DIW and doctor blade patterning (weak shear force) approaches. The DIW printed films exhibited an overall more uniform arrangement of fibrils and better control during the aligned film preparation. Thus, a higher tensile strength (40 ± 0.7 MPa) of the PLCNFsB-40% film than that of the DBLCNFsB-40% film (29 ± 1.19 MPa) was achieved. Overall, a combination approach of adding a green and inexpensive additive of betaine (chemical) and shear force-induced fibril orientation (mechanical) contributes to LCNFs films for applications in next-generation flexible electronics.