Cellulose-Based Light-Management Films with Improved Properties Directly Fabricated from Green Tea

Abstract

Tea polyphenols are a phenolic bioactive compound extracted from tea leaves and have been widely used as additives to prepare functional materials used in packaging, adsorption and energy fields. Nevertheless, tea polyphenols should be extracted first from the leaves before use, leading to energy consumption and the waste of tea. Therefore, completely and directly utilizing the tea leaf to fabricate novel composite materials is more attractive and meaningful. Herein, semi-transparent green-tea-based all-biomass light-management films with improved strength, a tunable haze (60–80%) and UV-shielding properties (24.23% for UVA and 4.45% for UVB) were directly manufactured from green tea by adding high-degree polymerization wood pulps to form entanglement networks. Additionally, the green-tea-based composite films can be produced on a large scale by adding green tea solution units to the existing continuous production process of pure cellulose films. Thus, a facile and feasible approach was proposed to realize the valorization of green tea by preparing green-tea-based all-biomass light-management films that have great prospects in flexible devices and energy-efficient buildings.

Translucent and Anti-ultraviolet Aramid Nanofiber Films with Efficient Light Management Fabricated by Sol–Gel Transformation

“…It is clear to see the background patterns covered with Film 0 with 10 mm distance (Figure d1), while the background patterns become vague to the naked eyes with the increasing content of ethanol in the coagulation bath. Consequently, the background patterns are difficult to be seen when covered with Film 75 and Film 100, displaying an obvious light scattering, which is referred to as the haze (Figure d4,d5). , Compared to other ANF films, Film 100 regenerated from the pure ethanol coagulation bath shows the highest haze, indicating that the first coagulation bath has a great effect on the haze property of the regenerated ANF films. Similarly, the haze of ANF hydrogels displays the same changing trends as that of ANF films, suggesting that the haze property of ANF films is decided directly by ANF gels.…”

“…It is obvious that all ANF films show a relatively homogeneous and dense texture from the surface to the inner. Nevertheless, the surface and cross section of ANF films become rougher and rougher with the increasing ethanol content in the first coagulation bath, directly leading to the increasing haze property of the ANF films. ,, Moreover, the SEM micrographs of the surface of regenerated ANF aerogel regenerated from the pure water (a1–a3) and alcohol coagulation bath (b1–b3) are also demonstrated in Figure S5. As we know, freeze-drying can retain the original structure of the gels.…”

Transparent Cellulose/Lignin Composite Films with Adjustable Haze and UV-Blocking Performance for Light Management

“…Cellulose, as the most abundant natural polymer on the earth, is mainly extracted (e.g., by pulping technology) from plants such as wood, cotton, bamboo, and grass. , In recent years, cellulose-based transparent films fabricated via various methods have been developed for application in light management. − Nanocellulose, including cellulose nanofibrils (CNFs) and cellulose nanocrystals (CNCs), is generally fabricated from cellulose fibers by chemical and/or mechanical treatment and has been used to prepare transparent light-management films . However, the high cost and complicated manufacturing process of nanocellulose limit the large-scale production of all nanocellulose-based transparent films .…”