Recyclable and Reusable Natural Plant‐Based Paper for Repeated Digital Printing and Unprinting

Abstract

Although paperless technologies are becoming ubiquitous, paper and paper‐based materials remain one of the most widely used resources, predicted to exceed an annual total of 460 million metric tons by 2030. Given the environmental challenges, deleterious impact on natural resources, and waste associated with conventional wood‐based paper manufacturing, developing more sustainable strategies to source, produce, and recycle paper from natural materials is essential. Here, the development and production of reusable and recyclable paper are reported. This approach offers a pathway for easily producing natural pollen grains via ecofriendly, economical, scalable, and low‐energy fabrication routes. It is demonstrated that the pollen‐based paper exhibits high‐quality printability, readability, and erasability, enabling its reuse. Based on the pH‐responsive morphological responses of engineered pollen materials, a method for hygro stable printing and on‐demand unprinting is presented. The reusability of the pollen paper renders it more advantageous than conventional single‐print wood‐based paper. This study thus provides possible pathways to utilize non‐allergenic pollen, which is renewable and naturally abundant, as a sustainable source of reusable paper. While this work primarily deals with paper, the methods described here can be extended to produce other products such as cartons and containers for the storage and transport of liquid and solid materials.

Pollen‐Based Magnetic Microrobots are Mediated by Electrostatic Forces to Attract, Manipulate, and Kill Cancer Cells

“…SFPµP-BioBots Fabrication: Natural sunflower pollen microparticles were defatted using a methodology reported before. [17,[48][49][50] . For this aim, 250 g of sunflower pollen microparticles were refluxed in 0.5 L of acetone under magnetic stirring at 50 °C and 220 rpm for 3 h. After that, acetone was decanted and 1 L of deionized water was added for 1 h. Subsequently, the resulting solution was filtrated through a 300 µm diameter pore size nylon mesh and 6 µm diameter pore size filter paper.…”

Responsive hydrogel microfibers for biomedical engineering

“…45,52,81 Since physiological activities of humans are always accompanied by pH changes, pH-responsive hydrogels, which could be greatly sensitive to external environmental stimuli, are recognized as a class of advanced intelligent biomaterials. [82][83][84][85] The silica nanoparticle (SNP)/polyacrylic acid (pAA) composite microfibers prepared by Haase et al were proved to be pH-responsive. 84 During the increase of pH values from 4 to 10, the spiral twisted microfibers expanded rapidly in volume with enhanced mechanical flexibility (Figure 6A).…”

Used tissue paper as a 3D substrate for non-enzyme glucose sensors

“…However, conventional tissue paper production needs a comprehensive process, including cutting, debarking, and slicing logs, then chemically turning them into cellulose pulp, followed by bleaching, screening, and washing with a number of different processes, eventually drying and rolling to the finished product. 36 Tissue paper production consumes high energy and has been increasing by 0.3% per year over the last two decades, which is far from the sustainable development scenario's target of a 0.6% reduction per year by 2030. The conventional recycling process of paper products, which accounts for 30% of the total municipal solid waste, consumes substantial energy and emits greenhouse gases and toxic chemicals.…”

“…The conventional recycling process of paper products, which accounts for 30% of the total municipal solid waste, consumes substantial energy and emits greenhouse gases and toxic chemicals. 36,37 Moreover, chemical additives and virgin wood pulp are required to maintain fiber length and tensile strength, which puts huge pressure on environmental protection and economic benefits. 38 Although some efforts have been made to recycle tissue paper into high-value advanced materials, such as sorbents for precious metal recycling 39 and aerogels for oil/water separation, 40 biomedical applications have received limited attention.…”