Microprocessor-based – Mixed Cellulose biodegradable nano green straw

Growing plastic products referenced led to increasingly serious environmental pollution problems. plastic straw environmental problems caused in particular. First, the huge amount of plastic straw, plastic straws for example, the US daily consumption to more than 500 million. Second, most of the plastic straw are disposable plastic pipette and because typically small size, light weight, can not be recycled lead. In order to address the potential environmental problems caused by plastic straw, a growing number of local governments and large enterprises in the implementation of the \”plastic limit.\” For example, in 2020 the company plans to Starbucks coffee chain bid farewell to all plastic straw, is expected to reduce the use of more than one billion plastic straw each year. Thus we can replace need for a biodegradable plastic pipette pipette on the market. Coated with a waterproof surface layer of wax paper, although paper made from straw can be degraded, but its poor aqueous stability, low mechanical strength, and high production costs, resulting in paper straw the straw can not be over environmental alternative embodiment of a plastic pipette. Cellulose contains the world\’s most abundant amount of natural polymer materials have good prospects in terms of alternative plastics. Natural wood contains 40-45% cellulose. More than 50% of the cellulose in the sugar cane bagasse residue after extraction of sucrose, but now substantially bagasse produced as waste. Cellulose has excellent mechanical properties (2-3GPa strength), low density (1.5 g / cm 3 ), low cost, biodegradability, etc., is an ideal alternative to plastics material. achievement Introduction University of Maryland Professor Lee Teng and Professor Hu Liangbing co-led team proposed an alternative method based on non-degradable plastic pipette composite nano micron cellulose and cellulose non-adhesive design and manufacture of the suction tube. micron cellulose and cellulose nano scale can be obtained from low-cost raw materials, bagasse, wood and the like. Slightly wet – mixed nano cellulose film may be rolled into the shape of a straw. After drying, the contact edges of the film can be closed, and sealing an interface (FIG. 1) is formed by a large number of internal hydrogen bonding. This method of making a micro – nano mixed cellulose binder and straw is avoidedWaterproof stencil sheet, reducing the cost and complexity of production process . Micro – Nano mixed cellulose outstanding performance of straw, having a is excellent in mechanical properties (tensile strength of about 70MPa, extending high breaking strain 12.7%), sufficient water repellency (wet mechanical strength is 10 times that of the commercial paper straw), cost , density (~ 0.66 g / cm 3 ) and high natural degradation of . Based on these advantages, micro – nanometer mixed cellulose instead of straw demonstrate the great potential of plastic straw. The recent achievements with \”All-Natural, Degradable, Rolled-Up Straws Based on Cellulose Micro- and Nano-Hybrid Fibers\” was published in internationally renowned journals Advanced Functional Materials on.

基于微-纳米混合纤维素的可降解环保吸管
Figure 1 in a wet state micro – nanometer mixed cellulose membrane is wound into a schematic view of the straw. (By binding the straw form a strong hydrogen bonds between the cellulose fibers achieved, without any additional binder)

Compared with the traditional paper straw contains only cellulose microns, solution containing many hydroxyl groups and having a larger specific surface area of ​​nanocellulose only greatly fill the gap between the micron cellulose, mixed imparting a dense structure film (FIG. 2a-f). At the same time, also enhances nanocellulose micro – mechanical properties of mixed cellulose nano-straw. Compared with the pipette micron cellulose, mixed cellulose straw bending strength increased by about 6-fold (FIG. 2H), tensile strength increased by about 70-fold (FIG. 2i). Micro – Mechanical Properties of mixed cellulose nano-straw also stronger than plastic straw. More dense texture mixed cellulose straw also have better water resistance, Micro Nano – mixed cellulose without delamination pipe may appear stable water for 4 hours.

基于微-纳米混合纤维素的可降解环保吸管
FIG. 2. (a) micron cellulose membrane, (b) nano-cellulose membrane, and (c) Micro Nano -SEM images of the mixed cellulose membrane. (D) [mu] m cellulose membrane, (e) nanometer cellulose membrane and (f) of micro – mixing nano schematic cellulose membrane. (G) Micro – Nano mixed cellulose pipette physical FIG. (H) comparing micron cellulose straw, straw cellulose nano, micro – mixed cellulose nano-straw, flexural strength plastic straw. (I) Comparative micron cellulose straw, straw cellulose nano, micro – mixed cellulose nano-straw, tensile strength plastic straw.

In addition, the team also built by classical molecular dynamics simulation models to achieve large scale coarse analog cellulose, and further confirmed the excellent mechanical properties of the composite cellulose from the mechanism. Cellulose and cellulose chains broken during stretching does not occur, but since the slip destruction occurs between the cellulose molecular dynamics simulation is also very good interpretation of this process. Figures 3a-c show different scales cellulose curve and sliding displacement force per unit area in the drawing process, jagged curve shows the hydrogen bond formation, destruction and re-formation process was destroyed. The results are shown in FIG. 3 nanocellulose (FIG. 3c) micron cellulose ratio (FIG. 3a) has a higher strength, but exhibits a lower damage displacement. When we micro – mixing the nano-cellulose was found not only to maintain a high strength, but also to a larger damage displacement good inheritance (Figure 3b). Thus Nanocellulose due to higher stress levels 17 times reflect damage to the micron cellulose performance by calculating the different mixing ratios of cellulose fracture energy (FIG. 3d) was found, but the micro – since its mixed cellulose nano balance the contradiction between stress levels and slip away to achieve a significantly improved mechanical properties, which is the preparation of high-performance industrial micro – provides a solid theoretical foundation nano-cellulose mixed straw, while the development team on crude cellulose granulated molecular dynamics model can also be widely used for more in-depth study of cellulose bigger scale.

基于微-纳米混合纤维素的可降解环保吸管
Figure 3. curve cellulose and sliding displacement force per unit area during drawing. (A) nano-cellulose content of 0% (pure cellulose microns), (b) nano-cellulose content 57.1%, (c) nano-cellulose content of 100% (pure nanocellulose), (d) Normalized Fracture Energy with the change of nano cellulose content (micron cellulose as a reference line).

cellulose have shown strong competitive edge and gradually widespread attention, with its low-cost, complete degradation of characteristics instead of plastic straw with a great prospect. Based on the existing straw paper manufacturing machine can easily micro – low cost mass production of mixed cellulose nano-straw, while it is also excellent mechanical properties to provide a strong competition for industrial production. The full text link:

https://doi.org/10.1002/adfm.201910417

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