From Corn Husks to Scalable, Strong, Transparent Bio‐Plastic Using Direct Delignification‐Splicing Strategy

Abstract

Biomass‐based plastics (BPs), produced from natural polymers using a bottom‐up strategy, have been used to alleviate the environmental pollution caused by petrochemical‐based plastics (PCPs). Such BPs, however, typically require complex manufacturing processes, resulting in higher costs and reduced eco‐friendly features. Herein, a delignification‐splicing‐based strategy without adhesives for directly converting corn (Zea mays L.) husks to corn husk‐based plastic (CHP) is described. During this process, lignin is removed from the corn husks and the pores collapse to form a dense structure. The CHP, which combines high mechanical strength (118 MPa) and a Young's modulus of 7.8 GPa with excellent light transmittance (86%), can be prepared in large sheets and can potentially replace non‐renewable, non‐biodegradable PCPs. Each hm2 of cornfield can generate 1.2 hm2 of CHP annually using the strategy. The process is simple, green, scalable, and as low cost as traditional PCPs since the only consumables are corn husks, NaClO, and water. Functional CHPs, such as fluorescent or hydrophobic CHPs, can be fabricated by impregnating delignified corn husk with carbon dots before pressing or by post‐pressing hydrophobilization, respectively. This work develops an alternative green and sustainable technology for eco‐friendly BPs, adds value to agricultural waste, and reduces greenhouse gas emissions.

Transparent Bioplastics from Super-Low Lignin Wood with Abundant Hydrophobic Cellulose Crystals

“…The X-ray diffraction patterns of the W-BPs (Figure b) indicated that, compared with natural wood, the crystalline structure of cellulose I was well maintained under different delignification conditions. , The crystallinity index can be calculated according to the Segal method, and the crystallinities of NaOH-H 2 O 2 -W-BP and NaClO 2 -W-BP are 73 and 62%, respectively, revealing that more amorphous cellulose was removed from NaOH-H 2 O 2 -W-BP than from NaClO 2 -W-BP. Notably, the ratio of the (200) to (110) crystal plane of NaOH-H 2 O 2 -W-BP is apparently larger than those of NW and NaClO 2 -W-BP, indicating that more hydrophobic (200) crystal planes of cellulose are exposed in NaOH-H 2 O 2 -W-BP .…”

“…40−42 The X-ray diffraction patterns of the W-BPs (Figure 2b) indicated that, compared with natural wood, the crystalline structure of cellulose I was well maintained under different delignification conditions. 43,44 The crystallinity index can be calculated according to the Segal method, 38 and the crystallinities of NaOH-H 2 O 2 -W-BP and NaClO 2 -W-BP are 28 Furthermore, the container with NaOH-H 2 O 2 -W-BP and ethanol was vigorously shaken to obtain a suspension of cellulose nanomaterials. Figures 2c and S5 show the TEM images of the above cellulose nanomaterials.…”

Synthesis and Reduction Processes of Silver Nanowires in a Silver(I) Sulfamate–Poly (Vinylpyrrolidone) Hydrothermal System

“…Compared with that of silver porous hollow spheres [34], the ratio of intensities of the peaks (111) to (200) recorded in Figure 1 is larger, might further indicating the 1D growth along (111) direction. Figure 2 shows the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images [37][38][39][40] of the Ag nanowires [10,25,26]. Figure 2a shows the Figure 2 shows the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images [37][38][39][40] of the Ag nanowires [10,25,26].…”

“…Figure 2 shows the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images [37][38][39][40] of the Ag nanowires [10,25,26]. Figure 2a shows the Figure 2 shows the scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images [37][38][39][40] of the Ag nanowires [10,25,26]. Figure 2a shows the overall morphology of the Ag nanowires with lengths of up to tens of micrometers.…”

H2O2 Solution Steaming Combined Method to Cellulose Skeleton for Transparent Wood Infiltrated with Cellulose Acetate

“…Transparent wood has potential applications in energy-efficient buildings and electronic devices, owing to its high optical transmittance, low thermal conductivity, and high safety [ 1 , 2 ]. Various delignification methods have been developed to remove lignin from wood, including sodium chlorite (NaClO 2 ) [ 1 ], sodium hypochlorite (NaClO) [ 3 ], sodium hydroxide/sodium thiosulfate (NaOH/NaS 2 O 3 ) [ 2 ], and hydrogen peroxide (H 2 O 2 ) steaming [ 4 ], all of which provide well-preserved cellulose skeletons for transparent wood through infiltration with epoxy resin, PMMA, PVA, PLA, and PVP [ 5 , 6 , 7 , 8 , 9 ]. Previous studies have demonstrated that H 2 O 2 steaming, a green and highly efficient delignification method, provides a wood skeleton with a very low content of residual lignin, which could be used further as a skeleton for transparent wood [ 4 , 10 ], catalyst supports [ 11 ], solar evaporation generators [ 12 ], and bioplastics [ 13 , 14 ].…”