Bionic smart recycled paper endowed with amphiphobic, photochromic, and UV rewritable properties

Design of a Waste Paper-Derived Chemically 'Reactive' and Durable Functional Material with Tailorable Mechanical Property Following an Ambient and Sustainable Chemical Approach

Controlled tailoring of mechanical property and wettability is important for designing various functional materials. The integration of these characteristics with waste materials is immensely challenging to achieve, however, it can provide sustainable solutions to combat relevant environmental pollutions and other relevant challenges. Here, the strategic conversion of discarded and valueless waste paper into functional products has been introduced following a catalyst-free chemical approach to tailor both the mechanical property and water wettability at ambient conditions for sustainable waste management and controlling the relevant environmental pollution. In the current design, the controlled and appropriate silanization of waste paper allowed to modulate both the a) porosity and b) compressive modulus of the paper-derived sponges. Further, the association of 1,4-conjugate addition reaction between amine and acrylate groups allowed to obtain an unconventional waste paper-derived chemically 'reactive' sponge. The appropriate covalent modification of the residual reactive acrylate groups with selected alkylamines at ambient conditions provided a facile basis to tailor the water wettability from moderate hydrophobicity, adhesive superhydrophobicity to non-adhesive superhydrophobicity. The embedded superhydrophobicity in the waste paper-derived sponge was capable of sustaining large physical deformations, severe physical abrasions, prolonged exposure to harsh aqueous conditions, etc. Further, the waste paper-derived, extremely water-repellent sponges and membranes were successfully extended for proof-of-concept demonstration of a practically relevant outdoor application, where the repetitive remediation of oil spillages has been demonstrated following both selective absorption (25 times) of oils and gravity-driven filtration-based (50 times) separation of oils from oil/water mixtures at different harsh aqueous scenarios.

Performance of zinc oxide quantum dots coated paper and application of fluorescent anti-counterfeiting

Fluorescent anti-counterfeiting is one of the most widely used anti-counterfeiting technologies at present. The demand to develop new anti-counterfeiting materials and technology is more and more urgent. Zinc oxide quantum dots (ZnO QDs) have superior fluorescent properties under ultraviolet light, making them a suitable replacement for traditional phosphors for anti-counterfeiting printing, which is environmentally friendly and meets the needs of sustainable development. In this paper, water-soluble ZnO QDs with an average particle size of 5.64 nm were prepared. Paper coated by ZnO QDs was obtained after ultrasonic treatment, which could emit bright yellow fluorescence when excited by ultraviolet light. As the concentration of ultrasonic solution is increased, the loading amount of ZnO QDs on the coated paper increased gradually, reaching the maximum when the concentration is increased to 1molL^-1, which then does not change with an increase in concentration. The fluorescent intensity of the coated paper was consistent with the changing trend of the loading amount. The coated paper has excellent optical stability, is easy to recycle, and provides simple identification of authenticity by ultraviolet light and anti-copy functionality. Their application in packaging and printing is of great significance to the development of complex, concealed and non-repeatable anti-counterfeiting technology.