With their impressive properties such as remarkable unit tensile strength, modulus, and resistance to heat, flame, and chemical agents that normally degrade conventional macrofibers, high-performance macrofibers are now widely used in various fields including aerospace, biomedical, civil engineering, construction, protective apparel, geotextile, and electronic areas. Those macrofibers with a diameter of tens to hundreds of micrometers are typically derived from polymers, gel spun fibers, modified carbon fibers, carbon-nanotube fibers, ceramic fibers, and synthetic vitreous fibers. Cellulose nanofibers are promising building blocks for future high-performance biomaterials and textiles due to their high ultimate strength and stiffness resulting from a highly ordered orientation along the fiber axis. For the first time, an effective fabrication method is successfully applied for high-performance macrofibers involving a wet-drawing and wet-twisting process of ultralong bacterial cellulose nanofibers. The resulting bacterial cellulose macrofibers yield record high tensile strength (826 MPa) and Young's modulus (65.7 GPa) owing to the large length and the alignment of nanofibers along fiber axis. When normalized by weight, the specific tensile strength of the macrofiber is as high as 598 MPa g cm , which is even substantially stronger than the novel lightweight steel (227 MPa g cm ).

Cellulose nanofibrils are attractive as building blocks for advanced photonic, optoelectronic, microfluidic, and bio-based devices ranging from transistors and solar cells to fluidic and biocompatible injectable devices. For the first time, an ultrastrong and ultratough cellulose film, which is composed of densely packed bacterial cellulose (BC) nanofibrils with hierarchical fibril alignments, is successfully demonstrated. The molecular level alignment stems from the intrinsic parallel orientation of crystalline cellulose molecules produced by Acetobacter xylinum. These aligned long-chain cellulose molecules form subfibrils with a diameter of 2-4 nm, which are further aligned to form nanofibril bundles. The BC film yields a record-high tensile strength (≈1.0 GPa) and toughness (≈25 MJ m −3 ). Being ultrastrong and ultratough, yet the BC film is also highly flexible and can be folded into desirable shapes. The BC film exhibits a controllable manner of alignment and is highly transparent with modulated optical properties, paving the way to enabling new functionalities in mechanical, electrical, fluidic, photonics, and biocompatible applications.

An ultralight, elastic, cost-effective, and highly recyclable superabsorbent was fabricated from microfibrillated cellulose fibers for oil spillage cleanup.

No abstract

No abstract

No abstract

Photocatalytic H2 evolution (PHE) from extremely abundant seawater resources is an ideal way to secure sustainable H2 for humanity, but the saline in seawater easily competitively absorbs the active sites and poisons the catalyst. Herein, a series of low-cost alkali halide (NaI, KI, RbI, CsI, CsBr, and CsCl), analogous to the saline in natural seawater, was selected to modify carbon nitride (MX-CN) through one-step facile pyrolysis with the assistance of water. MX-CN possesses a large amount of negative charges, which could inhibit anion absorption, to some extent, preventing chloride corrosion. Importantly, it can greatly boost the electron transfer between MX-CN and triethanolamine (TEOA) (sacrificial agent) because the alkali cation in seawater can coordinate with TEOA, and easily come in contact with MX-CN through alkali-cation exchange and electrostatic attraction. Benefiting from it, the PHE performance in seawater is 200 times better than that of original CN in deionized water above, and the apparent quantum efficiency of MX-CN (CsI-CN) under 420 nm light irradiation comes to 72% in seawater, the highest value reported for seawater thus far. This work provides a new research direction for engineering the electron transfer pathway between the photocatalyst and sacrificial agent (e.g., pollutant) in natural seawater.

A new biosorbent material from eggshell membrane was synthesized through thiol functionalization, which is based on the reduction of disulfide bonds in eggshell membrane by ammonium thioglycolate. The thiol-functionalized eggshell membrane was characterized, and its application as an adsorbent for removal of Cr(VI), Hg(II), Cu(II), Pb(II), Cd(II), and Ag(I) from aqueous water has been investigated. The experimental results revealed that the adsorption abilities of the thiol-functionalized eggshell membrane toward Cr(VI), Hg(II), Cu(II), Pb(II), Cd(II), and Ag(I) improved 1.6-, 5.5-, 7.7-, 12.4-, 12.7-, and 21.1-fold, respectively, compared with that of the eggshell membrane control. The adsorption mechanism and adsorption performance, including the adsorption capacity and the kinetics of the thiol-functionalized eggshell membrane for the target heavy metals, were investigated. The effects of solution pH, coexisting substances, and natural water matrices were studied. The thiol-functionalized eggshell membrane can be used as column packing to fabricate a column for real wastewater purification.