Cellulose-based Films Research Articles

Facile Fabrication of High-Performance Composite Films Comprising Polyvinyl Alcohol as Matrix and Phenolic Tree Extracts.

Given that tree extracts such as tannin and lignin can be efficiently used as modifying materials, this helps to verify the global trend of energy saving and environment protection. Thus, bio-based biodegradable composite film incorporating tannin and lignin as additives, together with polyvinyl alcohol (PVOH) as a matrix (denoted TLP), was prepared. Its easy preparation process endows it with high industrial value in comparison to some bio-based films with complex preparation process such as cellulose-based films. Furthermore, imaging with scanning electron microscopy (SEM) shows that the surface of tannin- and lignin-modified polyvinyl alcohol film was smooth, free of pores or cracks. Moreover, the addition of lignin and tannin improved the tensile strength of the film, which reached 31.3 MPa as indicated by mechanical characterization. This was accounted for by using Fourier transform infrared (FTIR) and electrospray ionization mass (ESI-MS) spectroscopy, which showed that the physical blending of lignin and tannin with PVOH was accompanied by chemical interactions that gave rise to weakening of the prevailing hydrogen bonding in PVOH film. In consequence, the addition of tannin and lignin acquired the composite film good resistance against the light in the ultraviolet and visible range (UV-VL). Furthermore, the film exhibited biodegradability with a mass loss about 4.22% when contaminated with Penicillium sp. for 12 days.

Kombucha fermentation in yerba mate: Cellulose production, films formulation and its characterisation

The production of Kombucha fermented beverage generates a side-stream composed of bacterial cellulose, a source of biopolymer to develop food contact materials. This work aims to study Kombucha fermentation in yerba mate infusion to maximise cellulose production and its processing for film formulation. Yerba mate infusion with sucrose resulted in an extraordinary substrate for Kombucha fermentation with an optimised cellulose production of 19.4 g/l and 0.29 g/g of yield. Filmogenic dispersions were analysed in terms of rheology and particle size distribution. Microscopic characterisation of films exhibited homogeneous surfaces. The addition of glycerol, as well as the solids from the fermented broth, resulted in a significant increase in hydration and a reduction in elastic modulus, ultimate tensile strength and glass transition temperature of the films. The results revealed that the formulation containing the Kombucha fermented media showed similar properties to the glycerol plasticised material. This could be considered a novel result as it may replace the use of traditional plasticisers. Bioactive compounds from yerba mate provided an antioxidant activity greater than 95% of ABTS radical inhibition to cellulosic material, demonstrating that natural bioactive cellulose-based films are materials that potentially protect food products against oxidation.

Highly transparent, hydrophobic, and durable anisotropic cellulose films as electronic screen protectors

Cellulose films have attracted extensive interest in the field of burgeoning electronic devices. However, it remains a challenge to simultaneously address the difficulties including facile methodology, hydrophobicity, optical transparency, and mechanical robustness. Herein, we reported a coating-annealing approach to fabricate highly transparent, hydrophobic, and durable anisotropic cellulose films, where poly(methyl methacrylate)-b-poly(trifluoroethyl methacrylate) (PMMA-b-PTFEMA) as low surface energy chemicals was coated onto regenerated cellulose films via physical (hydrogen bonds) and chemical (transesterification) interactions. The resultant films with nano-protrusions and low surface roughness exhibited high optical transparency (92.3 %, 550 nm) and good hydrophobicity. Moreover, the tensile strength of the hydrophobic films was 198.7 MPa and 124 MPa in dry and wet states, respectively, which also showed excellent stability and durability under various conditions, such as hot water, chemicals, liquid foods, tape peeling, finger pressing, sandpaper abrasion, ultrasonic treatment, and water jet. This work provided a promising large-scale production strategy for the preparation of transparent and hydrophobic cellulose-based films for electronic device protection as well as other emerging flexible electronics.

Starch- and carboxymethyl cellulose-based films as active beauty masks with papain incorporation

This work aimed to evaluate the effects of the incorporation of papain in biopolymeric-based beauty face masks with exfoliation activity of the skin. The masks were produced by casting with starch and carboxymethyl cellulose blend (50:50 weight percentages). The macro and microstructure, protein distribution, thickness, moisture content, water contact angle, solubility matter, and mechanical properties were evaluated. Moreover, the in vitro proteolytic and exfoliation activity and storage stability were also evaluated. The films with papain had a more concise matrix which provided higher mechanical properties and lower water solubility when compared to the control film (without papain). Films with 1, 2, and 5 % of papain had enzymatic activity for casein and porcine skin substrates. The micrographs of porcine skin treated with 2 and 5 % of papain showed more difference when compared to the control sample, indicating the enzymatic exfoliation. Differently from the solution of papain, the enzyme that was immobilized in the films maintained its activity for up 90 days during the storage stability assay. Based on the physicochemical properties and proteolytic activities, the films preserved the exfoliation activity of papain and have interesting characteristics to act as beauty masks in the cosmetic field.

Additives for Realistic Biodegradable Cellulose-based Film with Mechanical and Antibacterial Properties

Developing the biodegradable and renewable materials in the food packaging industry has become one of the most important topics in modern society, where has attracted a lot of efforts in this field. In this review, we have discussed the additives that used to regulate the mechanical and antimicrobial properties by blending into cellulose and its derivatives. Cellulose is one of the best biomass composites for film formation with resource abundance and biodegradability. To realize the further benefits of cellulose and its derivatives in the food packaging manufacture, there are still a quantity of opportunities in improving the practicality and cost of the additives.

Cellulose-Based Films for Food Packaging Applications: Review of Preparation, Properties, and Prospects

Cellulose-Based Films for Food Packaging Applications: Review of Preparation, Properties, and Prospects

Cellulose-based films with internal plasticization with epoxidized soybean oil

A process was developed combining two natural-based products to obtain bio-based films. Industrial cellulose pulp was dissolved and mixed with epoxidized soybean oil (ESBO), which acts as an internal plasticizer. A distillable and recyclable ionic liquid-based solvent was used to dissolve the cellulose. Appropriate distribution of the cellulose/ESBO solution on glass surfaces and careful regeneration of the cellulose enabled the development of solvent-free and flexible cellulose films. Fourier transform infrared spectroscopy revealed the presence of the triglyceride structure and the absence of the epoxide ring in the films, confirming the chemical reaction between the hydroxyl and epoxide groups of cellulose. The resulting films were further characterized by scanning electron microscopy, dynamic scanning calorimetry, thermogravimetry, and mechanical tensile tests. The films were also evaluated by contact angle measurement, swelling ability, in vitro degradability and cytotoxicity. The results showed that the presence of ESBO can adjust both the flexibility and hydrophilicity of the cellulose films, resulting in materials suitable for a variety of applications.

Antimicrobial Edible Cellulose-Based (CB) Films and Coatings for Enhancing Microbial Safety of White Cheese During Storage

In this research, the antioxidant and antibacterial characteristics of edible cellulose-based film (CBEF) coating incorporated with β-carotene, Hesperedin and Propolis on the quality of the white cheese at 4°C were investigated. Samples evaluated were: Control, CBE films with 8 different contents containing natural or non-natural antimicrobial agents for 15 days at 5 day intervals. The antimicrobial effects of edible cellulosic films prepared with antimicrobial agents against Staphylococcus aureus and Escherichia coli, which are important food pathogens, were directly evaluated with artificially contaminated food samples under cold storage conditions. Fresh white cheese samples, which are one of the semi-hard traditional Turkish cheeses, were used for artificial contamination. The antimicrobial activity of the tested antimicrobial substances was measured by the paper disc method. The DPPH free radical scavenging activities, the total phenolic content, and the characteristics (FT-IR, DSC and TGA) of the CBEFs were investigated. All of the samples significantly reduced E. coli, S. aureus and total viable counts, as compared with control during the storage time. Specifically, it was determined that hesperidin sprayed films showed an antimicrobial effect on E.coli growth and carotene sprayed films showed an antimicrobial effect on S. aureus growth. Growth of both bacterial species was highly inhibited (>50%) in the presence of 20% propolis. It was concluded that β-carotene, hesperidin and propolis can be substituted as natural preservatives in white cheese. With this advanced packaging technology, food safety can be ensured, the shelf life of the product can be extended and food losses in this sector can be reduced.

Scaling-Up an Aqueous Self-Degassing Electrochemically Mediated ATRP in Dispersion for the Preparation of Cellulose-Polymer Composites and Films.

Electrochemically mediated atom transfer radical polymerization (eATRP) is developed in dispersion conditions to assist the preparation of cellulose-based films. Self-degassing conditions are achieved by the addition of sodium pyruvate (SP) as a ROS scavenger, while an aluminum counter electrode provides a simplified and more cost-effective electrochemical setup. Different polyacrylamides were grown on a model cellulose substrate which was previously esterified with 2-bromoisobutyrate (-BriB), serving as initiator groups. Small-scale polymerizations (15 mL) provided optimized conditions to pursue the scale-up up to 1000 mL (scale-up factor ~67). Cellulose-poly(N-isopropylacrylamide) was then chosen to prepare the tunable, thermoresponsive, solvent-free, and flexible films through a dissolution/regeneration method. The produced films were characterized by Fourier-transform infrared (FTIR), scanning electron microscopy (SEM), dynamic scanning calorimetry (DSC), and thermogravimetric analysis (TGA).

Novel Features of Cellulose-Based Films as Sustainable Alternatives for Food Packaging.

Packaging plays an important role in food quality and safety, especially regarding waste and spoilage reduction. The main drawback is that the packaging industry is among the ones that is highly dependent on plastic usage. New alternatives to conventional plastic packaging such as biopolymers-based type are mandatory. Examples are cellulose films and its derivatives. These are among the most used options in the food packaging due to their unique characteristics, such as biocompatibility, environmental sustainability, low price, mechanical properties, and biodegradability. Emerging concepts such as active and intelligent packaging provides new solutions for an extending shelf-life, and it fights some limitations of cellulose films and improves the properties of the packaging. This article reviews the available cellulose polymers and derivatives that are used as sustainable alternatives for food packaging regarding their properties, characteristics, and functionalization towards active properties enhancement. In this way, several types of films that are prepared with cellulose and their derivatives, incorporating antimicrobial and antioxidant compounds, are herein described, and discussed.

Cellulose-based films with enhanced load of nitrogen containing heterocycles: The impact on the surface morphology and proton conductivity

Nitrogen-containing heterocycles and cellulose are a promising pair of materials studied for use as polyelectrolytic membranes in fuel cells. However, the effect of the amount of heterocycle applied to the cellulosic substrate on the proton conductivity value is yet unknown. In order to provide new insights, in this paper we investigated the proton conductivity of three types of cellulose-based films that contain varying amounts of 1-hydroxybenzotriazole (HBT), a model heterocycle, in close correlation with other film surface properties such as X-ray diffraction, scanning electron microscopy (SEM), and atomic force microscopy (AFM). Furthermore, the effects of changing the kind of cellulosic surface on mechanical characteristics were assessed.

Cellulose-based films reinforced by in-situ generated ZnO for antimicrobial packaging

Cellulose-based films reinforced by in-situ generated ZnO for antimicrobial packaging

Rational design of stable fluorescent and hydrophobic cellulose-based film for full-band UV-blocking

Rational design of stable fluorescent and hydrophobic cellulose-based film for full-band UV-blocking

Metal-coordination and surface adhesion-assisted molding enabled strong, water-resistant carboxymethyl cellulose films

Developing renewable and biodegradable materials derived from cellulose is an attractive strategy to replace petroleum-derived plastics. In this study, metal ions (Cu2+, Fe3+, and Al3+) were added as a green binder into carboxymethyl cellulose (CMC) films to improve their mechanical properties and water resistance capacity. The tensile strengths of CMCAl3+ films were 133 MPa and 99 MPa at 43 % and 97 % humidity, respectively, which were comparable to or greater than those of the majority of commercially available plastics. Additionally, we proposed an interfacial adhesion-assisted molding strategy for forming cellulose-based films, avoiding film wrinkles and unevenness during drying and metal-coordination formation. The resultant films exhibited high transparency, excellent mechanical properties, water resistance capacity, ultraviolet light (UV) shielding, and antibacterial activity. In summary, the biodegradable, eco-friendly, excellent application performance, and adaptability of CMCMn+ (Mn+: polyvalent metal ions) films open new prospects as a viable alternative to non-biodegradable plastics.

Chitosan/bacterial cellulose films incorporated with tea polyphenol nanoliposomes for silver carp preservation

This study aimed to develop chitosan/bacterial cellulose-based films loaded with tea polyphenol-loaded chitosan coated nanoliposomes (CS-TP-lip) as an active agent for food preservation. The effects of the CS-TP-lip on the physicochemical properties of composite films were systematically evaluated. The CS-TP-lip exhibited spherical shapes with an average particle size of about 300 nm. Scanning electron microscopy and Fourier transform infrared spectroscopy analyses suggested high compatibility between the CS-TP-lip and film matrix through intermolecular interactions. Furthermore, due to the CS-TP-lip's presence, the elongation at break and thermal stability of the films could be enhanced to reach 75.14 ± 1.2 % and 395.33 °C, respectively, and the stability of tea polyphenol could be increased to prolong its functioning time. The films were successfully used as packaging materials for fish fillet preservation. Therefore, the developed nanocomposite films exhibit great promise as a new generation of biodegradable, sustainable, and bioactive film for food preservation.

Transparent Cellulose-Based Film with High UV-Blocking Performance Fabricated by Surface Modification using Biginelli Reaction.

Efficient and sustainable ultraviolet (UV)-blocking materials are of great interest in many fields. Herein, novel cellulose-based UV-blocking films are developed via surface modification using the Biginelli reaction. The resulting films exhibited excellent visible transparency (80%) at 550nm and superhigh UV-blocking performance, which can shield almost 100% UVA and UVB. These features are very stable even the materials are being subjected to solvents, UV irradiation, and thermal treatment. This work provides a novel and facile strategy to fabricate functional cellulose-based films with superhigh anti-ultraviolet performance.

Eco-Friendly and Complete Recycling of Waste Bamboo-Based Disposable Paper Cups for Value-Added Transparent Cellulose-Based Films and Paper Plastic Composites.

Disposable paper cups are widely used in daily life and most of them are landfilled or incinerated after use, resulting in a serious ecological hazard and significant waste of resources due to the usage of thin polyethylene (PE) as their inner coating. Hence, converting these common solid domestic wastes into high-value added materials is attractive and meaningful. In this study, transparent cellulose-based films were achieved from old bamboo-based disposable paper cups after pretreatment through using the room ionic liquid 1-allyl-3-methylimidazolium chloride (AmimCl) as solvent. The cellulose-based film with a dense texture demonstrated a relatively nice mechanical and UV-shielding performances, and its tensile strength was as high as 48 MPa, much higher than that of commercial polyethylene (PE, 12 MPa) film. Thus, the resultant cellulose-based film showed a great potential in the packaging field. Besides, the flexible paper plastic composites (PPC) were also fabricated from the rest thin PE coating with the stuck fibers, and it was found that PPC showed excellent mechanical property and hydrophobicity. Consequently, a feasible and eco-friendly process of recycling and reusing waste disposable paper cups was developed to achieve a complete utilization and valorization of waste disposable paper cups.

Molecular design and structural optimization of nanocellulose-based films fabricated via regioselective functionalization for flexible electronics

Nanocellulose backbones highly regioselectively substituted with thiophene and long fatty acid side chains were synthesized via a protecting group strategy. The presence of long-chain pendants balanced the torsional conformations of the nanocellulose backbone caused by large thiophene molecules on the nanostructured substrate, imparting enhanced electrical conductivity to the nanomaterial. The formation of a percolation network provided a conduction path and reinforcing effects enhancing energy transfer. The fabricated strong, flexible, and conductive regioselectively nanofibrillated cellulose-based films were demonstrated to be a potential alternative to conventional semiconductors. Optimization of the structure of nanocellulose backbones resulted in higher interaction between the active moieties and demonstrated higher electrical conductivity (279.10 μS/cm) when compared to randomly functionalized nanocellulose (65.05 μS/cm). The molecular design of the structures of nanocellulose may allow the fabrication of materials with consistent and reproducible properties. The well-defined architecture of functionalized nanostructures is an important step toward acceptance of nanocellulose as a bio- component in advanced materials.

Strong Bacterial Cellulose-Based Films with Natural Laminar Alignment for Highly Sensitive Humidity Sensors.

Humidity sensors have been widely used for humidity monitoring in industry and agriculture fields. However, the rigid structure, nondegradability, and large dimension of traditional humidity sensors significantly restrict their applications in wearable fields. In this study, a flexible, strong, and eco-friendly bacterial cellulose-based humidity sensor (BPS) was fabricated using a two-step method, involving solvent evaporation-induced self-assembly and electrolyte permeation. Rapid evaporation of organic solvent induces the formation of nanopores of the bacterial cellulose (BC) surface and promotes structural densification. Furthermore, the successful embedding of potassium hydroxide into the sophisticated network of BC effectively enhanced the sensing performance of BPS. The BPS exhibits an excellent humidity sensing response of more than 103 within the relative humidity ranging from 36.4 to 93% and strong (66.4 MPa) and high flexibility properties owing to the ultrafine fiber network and abundant hydrophilic functional groups of BC. Besides being strong and thin, BPS is also highly flexible, biodegradable, and humidity-sensitive, making it a potential candidate in wearable electronics, human health monitoring, and noncontact switching.

Green fabrication of high strength, transparent cellulose-based films with durable fluorescence and UV-blocking performance

Fluorescent cellulose films with high strength, transparency and UV resistance were prepared. Such extraordinary properties allow application prospects in UV protection, anti-counterfeiting and remote LED devices.