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Biofouling on surfaces of various materials has attracted considerable attention in biomedical and marine industries. Surface grafting based on covalent surface‐initiated polymerization offers a popular route to address this problem by providing diverse robust polymer coatings capable of preventing the biofouling in complex environments. However, the existing methods for synthesizing polymer coatings are complicated and rigorous, or require special catalysts, greatly limiting their practical applications. In this work, a radical‐cation‐based surface‐initiated polymerization protocol to graft the surface of darkened trans‐polyisoprene (TPI) rubber with a thermo‐responsive smart polymer, poly(N‐isopropylacrylamide) (PNIPAM), through a simple iodine doping process is reported. A series of characterizations were performed to provide adequate evidence to confirm the successful grafting. Combining the thermal sensitivity of PNIPAM with the photothermal conversion ability of the darkened rubber, efficient bacteria‐killing and antifouling capabilities were successfully achieved as a result of temperature‐controlled iodine release and switchable amphiphilicity of PNIPAM. Smart coatings: Radical cations are generated when rubber is exposed to iodine treatment. These radical cations not only facilitate photothermal conversion, but also initiate surface polymerization. A successful example of poly(N‐isopropylacrylamide) (PNIPAM) brushes grafted on darkened rubber demonstrates that the combination of thermoresponsive polymers with photothermal conversion opens a new avenue for exploiting light‐triggered bacteria‐killing and antifouling coatings. [ABSTRACT FROM AUTHOR]

Organic conjugated polymers with low energy bandgaps are emerging as a particular class of near-infrared (NIR) photothermal conversion materials. However, these polymers routinely possess high phase transition temperatures due to the rigid skeleton and strong intermolecular interactions. Conjugated polymers can rarely be thermally processed at low temperature, especially below 100 °C. This work formulates a concept of post-darkening modeling production ( p-DMP) by which the thermoplastic non-conjugated trans-polyisoprene (TPI) is refreshed into a photothermal conversion material with high light use efficiency. Two steps, including the customizable shaping at low temperature and iodine vapor-tailored 'darkening', ensure the ease of preparing photothermal conversion devices with desirable topologies. A few characterizations, with the combination of density functional theory (DFT) calculations, provide reasonable explanations for understanding the 'darkening' process of TPI in iodine atmosphere. In particular, the p-DMP is successfully extended to three-dimension (3D) printing, opening an avenue to fabricate personalized photothermal products, for example, a sunlight-directed physiotherapy device for healthcare of articular tissues. [ABSTRACT FROM AUTHOR]

Photothermal materials (PTMs) have been intensively investigated in the fields of photothermal conversion. Superior to solid PTMs, liquid PTMs are leading the trends in satisfying the demands of high flexibility and easy recycling. Successful examples of liquid PTMs are mostly formulated by dispersing solid PTMs in solvents, but suffer from the problems of phase segregation and solvent pollution. In this work, a low‐cost formulation is proposed, which involves an oxidative product of ethyl oleate by iodine. It is an intrinsic liquid PTM, preserving the fluidic nature as well as possessing considerable ability for photothermal conversion. In addition to understanding the mechanism of light absorption in the visible and even near infrared windows, two examples are presented to demonstrate the great potential of liquid PTMs in broad areas such as light sensing and energy storage. [ABSTRACT FROM AUTHOR]

Abstract: Decomposition and repolymerization of conjugated polymers offer great promise for developing recyclable photothermal conversion materials, which yet remain challenging. Herein, a crosslinked conjugated polymer based on a dynamic covalent bond of Schiff base is developed. This polymer possesses photothermal conversion efficiency as high as 90.4 %. Decomposition of the polymer under specialized conditions is corroborated by various characterizations. The kinetics study is also investigated to understand this degradation process. Furthermore, those decomposed species can be repolymerized back to conjugated polymers which possess the same photothermal conversion efficiency as the pristine polymer. Such a degradable and recyclable photothermal polymer is successfully used as a heat source for photothermal‐electrical conversion to generate Seebeck voltage under either near infrared (NIR) irradiation or solar illumination. [ABSTRACT FROM AUTHOR]