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A convenient strategy is proposed to fabricate chiral nematic composite films by intercalating cationic poly(ethylene imine) into the swollen matrix of self-assembled cellulose nanocrystal films. The composite films exhibit an extremely high folding endurance. Moreover, the composition also leads to a fluorescence enhancement effect, endowing the films with circularly polarized luminescence and optical responsiveness. [Display omitted] • Circularly polarized luminescence (CPL) CNC composite films are fabricated by matrix swelling and in-situ insertion method. • The composite CNC films exhibit extremely high folding endurance and solvent resistance. • The CPL handedness and dissymmetry factors of the composite films can be controlled. • Application in anti-counterfeiting patterns is demonstrated. Cellulose nanocrystal (CNC)-based materials have gained increasing attention because of their great potential applications in optical devices, anticounterfeiting and structural coatings. However, due to the inherent brittleness of CNC, fabricating highly strong and solvent-resistant CNC derived materials is still an important and challenging task. Here, a straightforward, matrix swelling and in-situ insertion method is developed to fabricate chiral nematic composite films by intercalating poly(ethylene imine) (PEI) into the as-prepared swollen matrix of CNC films. The resulting composite CNC films exhibit a great increase in ultimate strain and toughness and especially have an extremely high folding endurance. Notably, the intercalation of PEI into CNC films also leads to a fluorescence enhancement effect, which endows the films circularly polarized luminescence (CPL) properties. The CPL handedness and dissymmetry factors (glum) of the composite films can be controlled. Furthermore, the CNC composite films display optical responsiveness (structure color, fluorescence intensity) to various stimuli, including ethanol and formaldehyde environments. We expect the current in-situ intercalation technique to be promising in manufacturing foldable encryption materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pre-oxidation enhances specific surface area by 54.6% in CO 2 activation and 30.0% in H 2 O activation. • O 2 breaks rigid structure of biochar, forming activated carbon of microporous with larger diameters. • O 2 promotes conversion of olefinic C = C to aromatic C = C in activation, accelerating aromatization. • Promoting pores formation of O 2 is confirmed in activation of cellulose, pine needle and spirulina. Carbonization plus activation of resulting biochar is a commonly used method for producing activated carbon (AC) from biomass. Nevertheless, carbonization produces biochar of highly aromatic nature, increasing difficulty for creating pores via activation. Herein, O 2 (7.7%) was introduced to pre-oxidize lotus root and other biomasses-derived biochar before being activated with CO 2 or H 2 O for tackling chemical inertness of biochar at 800 °C. The results indicated that O 2 could enhance mass yield of AC (by 16.5% in CO 2 activation and 50.6% in a H 2 O activation) and bio-oil. Moreover, O 2 oxidized organics on AC, forming oxygen-containing aliphatic structures. Such a transformation enhanced reactivity of biochar with CO 2 or H 2 O, facilitating generation of pores. The AC from activation with O 2 -CO 2 was significantly higher than that from CO 2 alone (533.7 m2 g−1 of AC from O 2 -CO 2 activation versus 345.2 m2 g−1 of AC from CO 2 activation). O 2 also could remarkably increase the specific surface area of AC activated with H 2 O by 30.0%. Such an enhancement in pore structures was confirmed in activation of cellulose, pine needle and spirulina with O 2 presence. The pre-oxidation activated biochar destroyed partially rigid structure, facilitating gasification with CO 2 /H 2 O, forming dominantly micropores with enlarged diameters. The characterization with in-situ IR indicated that O 2 could enhance aromatization via aiding formation of aromatic C = C from olefinic C = C, producing AC of more regular alignments of carbon crystals. [ABSTRACT FROM AUTHOR]

[Display omitted] • Multiblock copolymer electrolyte is prepared by RAFT technique for the first time. • Self-oriented LCs construct rapid ion channels for efficient ion transport. • Analytic methods and DFT calculation reveal the interactions in electrolytes. • All-solid-state LIBs display stabilized long-cycling and rate capability. Liquid crystals (LCs) with characteristics of self-orientation have exhibited superiorities in construction of ordered ion channels for rapid Li-ion transport. Herein, reversible addition-fragmentation chain transfer (RAFT) polymerization is employed to synthesize a unique type of boron-containing LCs based ABCBA type multiblock copolymers for the first time. The composite block copolymer electrolytes (BCPEs) are fabricated by introducing the copolymer electrolytes into glass fiber separator via solution-casting method. Noteworthily, LCs can not only provide ordered ion channels for efficient ion conduction, but also ameliorate the mechanical strength. Meanwhile, the nitrile groups with high polarity from LCs are able to further facilitate lithium salt dissociation and reinforce electrochemical stability of the system. Crucially, boron elements with electron deficiency can anchor anions and adsorb impurities to endow BCPEs with boosted ion transport capability and sufficient electrochemical stability. Consequently, the well-designed electrolyte shows high ionic conductivity of 1.13 × 10−4 S cm−1 (30 °C), and broadened electrochemical stability window of 4.85 V. Impressively, the assembled Li/LiFePO 4 cells and even Li/LiMn x Fe 1-x PO 4 high-voltage cells exhibit remarkable performances. This work provides a synthetic strategy of structure-controlled polymer electrolyte matrix and illustrates that the BCPEs are definitely a category of satisfactory electrolyte candidate for high-performance solid-state lithium-ion batteries. [ABSTRACT FROM AUTHOR]