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1. Scalable mechanical exfoliation of two-dimensional nanosheets by polymer-assisted dry ball-mill of layered materials and insights from machine learning

   https://doi.org/10.1016/j.mtnano.2025.100604  

   Zhang, Jing; Zhai, Tianshu; Yan, Yunrui; Fang, Qiyi; Liu, Yifeng; Zhu, Yifan; Tu, Weiran; Lin, Chen-Yang; Wang, Yuguo; Lou, Jun (June 2025, Materials Today Nano)

   To fully capitalize on the unique properties of 2D materials, cost-effective techniques for producing high-quality 2D flakes at scale are crucial. In this work, we show that dry ball-milling, a commonly used powder-processing technique, can be effectively and efficiently upgraded into an automated exfoliation technique. It is done by adding polymer as adhesives into a ball mill to mimic the well-known tape exfoliation process, which is known to produce 2D flakes with the highest quality but is limited by its extremely low efficiency on large-scale production. Seventeen types of commonly seen polymers, including both artificial and natural ones, have been examined as additives to dry ball-mill hexagonal boron nitride. A parallel comparison between different additives identifies low-cost natural polymers such as starch as promising dry ball-mill additives to produce ultrathin flakes with the largest aspect ratio. The mechanical, thermal, and surface properties of the polymers are proposed as key features that simultaneously determine the exfoliation efficiency, and their ranking of importance in the mechanical exfoliation process is revealed using a machine learning model. Finally, the potential of the polymer-assisted ball-mill exfoliation method as a universal way to produce ultra-thin 2D nanosheets is also demonstrated. 

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2. Thermodynamic limits of the depolymerization of poly(olefin)s using mechanochemistry

   https://doi.org/10.1039/D4MR00079J  

   Chang, Yuchen; Nguyen, Van Son; Hergesell, Adrian H; Seitzinger, Claire L; Meisner, Jan; Vollmer, Ina; Schork, F Joseph; Sievers, Carsten (January 2024, RSC Mechanochemistry)

   Feasibility of mechanochemical depolymerization of commodity poly(olefin)s in a ball mill reactor is assessed using thermodynamic data. 

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3. Acceleration of Diels-Alder reactions by mechanical distortion

   https://doi.org/10.1126/science.adf5273  

   Zholdassov, Yerzhan S.; Yuan, Li; Garcia, Sergio Romero; Kwok, Ryan W.; Boscoboinik, Alejandro; Valles, Daniel J.; Marianski, Mateusz; Martini, Ashlie; Carpick, Robert W.; Braunschweig, Adam B. (June 2023, Science)

   A modified atomic force microscope is used to probe activation effects that may accelerate reactions in a ball mill. 

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4. Discrete Element Simulation and Economics of Mechanochemical Grinding of Plastic Waste at an Industrial Scale

   Elisavet Anglou, Yuchen Chang (July 2023, Computer aided chemical engineering)

   Antonios C. Kokossis; Michael C. Georgiadis; Efstratios Pistikopoulos (Ed.)

   Efficient and sustainable chemical recycling pathways for plastics are vital for addressing the negative environmental impacts associated with their end-of-life management. Mechanochemical depolymerization in ball mill reactors is a new promising route to achieve solid-state conversion of polymers to monomers, without the need for additional solvents. Physics-based models that accurately describe the reactor system are necessary for process design, scaling up, and reducing energy consumption. Motivated by this, a Discrete Element Method (DEM) model is developed to investigate the ball milling process at laboratory and industrial scales. The lab-scale model is calibrated and validated with data extracted from videos using computer vision tools. Finally, scaled-up ball mill designs capable of depolymerizing varying feeds of PET waste were simulated, and their capital and operating costs are estimated to assess the economic potential of this route. 

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5. Milligram-scale, temperature-controlled ball milling to provide an informed basis for scale-up to reactive extrusion

   https://doi.org/10.1039/D1GC02174E  

   Andersen, Joel; Starbuck, Hunter; Current, Tia; Martin, Scott; Mack, James (November 2021, Green Chemistry)

   Over the last several years, chemists and engineers have identified the utility of using twin-screw extruders for performing large-scale organic chemistry mechanochemically. This equipment is convenient as it is familiar to several relevant industries for its use in formulation, and it is also well-equipped for temperature control and intense grinding of materials. However, the research and development scale of mechanochemistry is just like that of conventional synthesis: milligrams. These milligram-scale reactions are performed in batch-type reactors, often a ball mill. Commercially available ball mills do not have strict temperature control, limiting the information that can be obtained to inform the scale-up process reliably. This work uses an in-house modified, temperature-controlled, ball mill to bridge the knowledge gap regarding predictable, well-informed, economical, and reliable mechanochemical scale-ups. Included in this work is the first extrusion example of a nucleophilic aromatic substitution. 

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