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Creators/Authors contains: "Zhou, Yilun"

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  1. Abstract Graphite is a commonly used raw material across many industries and the demand for high‐quality graphite has been increasing in recent years, especially as a primary component for lithium‐ion batteries. However, graphite production is currently limited by production shortages, uneven geographical distribution, and significant environmental impacts incurred from conventional processing. Here, an efficient method of synthesizing biomass‐derived graphite from biochar is presented as a sustainable alternative to natural and synthetic graphite. The resulting bio‐graphite equals or exceeds quantitative quality metrics of spheroidized natural graphite, achieving a RamanID/IGratio of 0.051 and crystallite size parallel to the graphene layers (La) of 2.08 µm. This bio‐graphite is directly applied as a raw input to liquid‐phase exfoliation of graphene for the scalable production of conductive inks. The spin‐coated films from the bio‐graphene ink exhibit the highest conductivity among all biomass‐derived graphene or carbon materials, reaching 3.58 ± 0.16 × 104S m−1. Life cycle assessment demonstrates that this bio‐graphite requires less fossil fuel and produces reduced greenhouse gas emissions compared to incumbent methods for natural, synthesized, and other bio‐derived graphitic materials. This work thus offers a sustainable, locally adaptable solution for producing state‐of‐the‐art graphite that is suitable for bio‐graphene and other high‐value products. 
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  2. To reduce the severe health risk and the huge economic impact associated with the fomite transmission of SARS-CoV-2, an imidazolium-based zwitterionic polymer was designed, synthesized, and demonstrated to achieve contact deactivation of a human coronavirus under dry ambient conditions that resemble fomite transmission. The zwitterionic polymer further demonstrated excellent antifouling properties, reducing the adhesion of coronavirus and the formation of bacteria biofilms under wetted conditions. The polymer was synthesized using a substrate-independent and solvent-free process, leveraging an all-dry technique named initiated chemical vapor deposition (iCVD). The broad applicability of this approach was demonstrated by applying the polymer to a range of substrates that are curved and/or with high-aspect-ratio nano/microporous structures, which remained intact after the coating process. The zwitterionic polymer and the synthesis approach reported here present an effective solution to mitigate viral transmission without the need for manual disinfection, reducing the health and economic impact of the ongoing pandemic. 
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