Nanocellulose: the natural super fiber that opens a new era of green nanomaterials

As the global dual-carbon strategy is further advanced and the concept of sustainable development becomes the core orientation of the industry, the environmental burden and resource shortage issues brought by traditional petroleum-based polymer materials have become increasingly prominent. The search for green, renewable, and high-performance alternative materials has become a core topic in the field of materials science. Nanocellulose ( Nanocellulose), as a new nanoscale functional material extracted from natural biomass, has become a research hotspot in global scientific research and industry with its unique performance advantages, wide range of raw material sources and completely degradable environmental protection properties. It is known as 'the most potential green nanomaterial in the 21st century' and is gradually reshaping the industrial structure of composite materials, biomedicine, food packaging, environmental filtration and other fields. In the process of domestic nanocellulose industrialization, Nanjing Tianlu Nano Technology Co., Ltd. (hereinafter referred to as 'Nanjing Tianlu Nano') has performed outstandingly. The company is located in Nanjing, the ancient capital of the Six Dynasties. It was established in May 2024. It focuses on the production, research and development and sales of nanocellulose series products. It also provides commercial application solutions based on nanocellulose. With its complete product system and technology accumulation, it has become one of the important forces in promoting the implementation of the domestic nanocellulose industry [3][7].

1. Core definition and classification of nanocellulose

Cellulose is the most widely distributed and abundant natural polymer organic compound in nature. It is widely found in various plant biomass such as wood, cotton and linen, bamboo, straw, sugarcane bagasse, etc. It is also a natural polymer synthesized by some microorganisms. Its basic structure is a linear polysaccharide chain formed by β-1,4-glucosidic bonds. Strong hydrogen bonds between molecules form a highly ordered crystal structure and a microscopic morphology alternating with amorphous regions.

Nanocellulose is a fibrous material obtained by hierarchically deconstructing natural cellulose to the nanometer scale through mechanical, chemical, biological or composite processes. Its diameter is usually controlled between 1 and 100 nanometers, and its length can reach hundreds of nanometers to several micrometers. It has typical nanomaterial characteristics and the inherent advantages of natural cellulose. According to preparation methods, microstructure and performance differences, nanocellulose is mainly divided into three major categories, which is also the most common classification standard in the industry:

Cellulose nanocrystals ( CNC) : Mainly prepared by acid hydrolysis, the amorphous region in cellulose is selectively removed and the high-purity crystalline region is retained. The finished product is in the shape of a short rod with extremely high crystallinity, strong rigidity, good transparency, and uniform size. It is suitable for use in optical materials, high-strength coatings and precision composite materials.

Cellulose nanofibers ( CNF) : are mostly prepared by high-pressure homogenization, micro-jet, TEMPO catalytic oxidation or enzyme-assisted methods. They retain the alternating structure of cellulose crystal regions and amorphous regions. They are elongated fibers with a large aspect ratio, excellent flexibility, easy to form a three-dimensional network structure, excellent film formation and dispersion, and a wider range of applicable scenarios.

Bacterial cellulose ( BC) : It is synthesized by fermentation of microorganisms such as Acetobacter and does not require complex extraction and dissociation processes. Its purity far exceeds that of plant-based nanocellulose. Its microscopic pore structure is uniform and delicate, and its biocompatibility is extremely high. It is an exclusive high-quality raw material in the fields of high-end biomedicine and wound dressings.

2. Core performance advantages of nanocellulose

Nanocellulose perfectly combines the environmental protection properties of natural biomass with the special properties of nanomaterials. Many core indicators far exceed those of traditional natural fibers and some synthetic polymer materials. This is also the core confidence that it can achieve cross-border applications in many fields. The main performance highlights are concentrated in the following aspects:

1. Ultimate mechanical properties

The specific strength and specific modulus of nanocellulose are much better than ordinary steel, and even comparable to some high-performance carbon fibers, with extremely strong reinforcing effects. Adding it as a filler to composite materials can quickly form a dense three-dimensional cross-linked network, effectively transmit stress, and greatly improve the tensile strength, flexural modulus and impact toughness of the matrix material without significantly increasing the weight of the material, achieving a perfect balance between light weight and high strength.

2. Green environmental protection and biocompatibility

The raw materials are taken from renewable plant straws, wood waste and other agricultural and forestry wastes, turning waste into treasure; after use, it can be completely biodegraded in the natural environment, will not produce microplastic pollution, and will not release toxic and harmful substances throughout the process, meeting the requirements of carbon neutrality and circular economy. At the same time, plant-based nanocellulose is non-toxic and non-irritating, and bacterial cellulose has excellent compatibility with human tissues, has no immune rejection, and can be directly used in the field of biomedicine.

3. High specific surface area and multifunctional modifiability

The nanoscale microstructure gives it a huge specific surface area, and its adsorption capacity and reactivity far exceed that of conventional fibers. The surface is rich in active functional groups such as hydroxyl groups and carboxyl groups, which can be functionally modified through various methods such as esterification, graft copolymerization, and ionic modification. It can easily be endowed with special properties such as antibacterial, conductive, hydrophobic, and lipophilic to adapt to the customized needs of different scenarios.

4. Excellent film-forming and rheological properties

Cellulose nanofibers can easily form transparent, flexible and excellent barrier films, which can replace traditional plastic packaging films. In aqueous systems, nanocellulose suspensions have unique shear thinning properties and thixotropy, which can not only form a stable three-dimensional network to prevent particle settlement, but also reduce viscosity under the action of shear force, making it easy to process and form. It is an ideal thickener, stabilizer and suspending agent.

3. Mainstream preparation processes and technical characteristics

The performance of nanocellulose directly depends on the preparation process. Different processes are suitable for different raw materials and product needs. Currently, the preparation methods commonly used in industrialization and laboratories are mainly divided into three categories, each with its own advantages and disadvantages:

Chemical methods : acid hydrolysis and TEMPO selective oxidation are the main methods. The acid hydrolysis method (commonly used sulfuric acid and hydrochloric acid) specifically removes amorphous areas and prepares high-crystallinity CNC. The process is mature and the cost is controllable, but it will produce acidic wastewater and requires environmental protection treatment. The TEMPO oxidation method oxidizes the hydroxyl groups on the cellulose surface into carboxyl groups under mild conditions to improve fiber dispersion. It has high nanometerization efficiency and good product uniformity. It is currently the mainstream green process for preparing high-quality CNF. Nanjing Tianlu Nano has been deeply engaged in the research and development and production of TEMPO oxidized nanocellulose, and has launched TL-010-2, TL-010-5 and other related products. With precise process control, the products have excellent hydrophilicity, charge density and mechanical properties, adapting to the application needs of many fields.

Mechanical method : Plant fibers are directly dissociated into nano-scale fibers through high-pressure homogenization, micro-jet, ball milling, ultrasonic and other strong mechanical shearing forces. It does not require a large amount of chemical reagents. It is green and environmentally friendly and can completely retain the aspect ratio of cellulose. However, it consumes high energy and is suitable for large-scale production of CNF. It is often combined with chemical pretreatment to reduce mechanical load and improve dissociation efficiency. Nanjing Tianlu Nano uses mechanical methods to prepare a variety of nanocellulose products, using non-wood fibers such as corn straw, corn cobs, reeds and wood cellulose as raw materials to create green, natural, non-toxic and degradable products, covering TL-015, TL-016, TL-017 and other models, which are widely used in papermaking, packaging, coatings and other fields.

Biological method : Cellulase is used to specifically degrade the amorphous region of cellulose. The reaction conditions are mild, low energy consumption, no pollution, high product purity, and stable performance. However, the cost of enzyme preparations is high and the reaction cycle is long. Currently, it is mostly used for laboratory research and development, and large-scale industrial applications are still optimizing costs and reaction efficiency. Nanjing Tianlu Nano has also deployed products related to biological methods, launching bacterial cellulose dispersion TL-008, which is purified with sodium hydroxide and can be used in special scenarios such as high-strength gels, special papers, pharmaceutical excipients, and facial masks, demonstrating the company's diversified product research and development capabilities.

4. Multiple application scenarios of nanocellulose

With its comprehensive performance advantages, nanocellulose has broken through the limitations of a single material and has been applied in many fields such as industrial manufacturing, biomedicine, food packaging, environmental protection, daily cosmetics and cosmetics, and its application scenarios continue to expand. Based on its own product advantages, Nanjing Tianlu Nano has continuously extended the application scenarios of nanocellulose, forming an application layout covering multiple fields such as biomedicine, environmental protection, papermaking and printing, energy, coatings and adhesives. Its products not only meet the needs of conventional fields, but also achieve breakthroughs in high-end scenarios, becoming an important bridge between nanocellulose technology and industrial applications [2].

1. Composite material reinforcement field

As a high-performance reinforcing filler, it is widely used in the modification of composite materials such as plastics, rubber, paper, and coatings. In the papermaking industry, it can improve paper strength, density and printing performance, and reduce the amount of wood pulp; in plastic modification, it can replace part of glass fiber and synthetic fillers to prepare degradable bio-based composite materials, which can be used in automobile interiors, home appliance casings, packaging materials, etc., reducing the carbon footprint of products.

2. Biomedical field

Bacterial cellulose and high-purity CNF are ideal raw materials for medical materials and can be used to prepare wound dressings, artificial skin, tissue engineering scaffolds, drug sustained-release carriers, etc. Nanocellulose dressings can create a moist healing environment, promote wound repair, and have both breathability and antibacterial properties; the porous structure of tissue engineering scaffolds facilitates cell adhesion and nutrient exchange, and can be used for tissue repair such as cartilage and cornea; after functional modification, it can also be used for targeted drug delivery to improve drug efficacy and reduce side effects.

3. Food and packaging fields

Prepare transparent degradable food packaging film, which has excellent oxygen and oil barrier properties, extends the shelf life of food, and completely replaces traditional plastic cling film; as a food additive, it is used as a thickener, stabilizer, and suspending agent, and is used in drinks, sauces, and baked goods to improve the taste and stability of food. It is safe and non-toxic; it can also be used in food preservation coatings to achieve long-term preservation of fruits and vegetables.

4. Environmental protection and daily chemical fields

Utilize high specific surface area and porous structure to prepare air filtration membranes and water treatment adsorption materials, which can efficiently absorb particulate matter, heavy metal ions and organic pollutants, with high purification efficiency and easy regeneration; in daily chemical products, it can be used in facial masks, lotions, sunscreens, etc. to improve the skin feel, stability and moisturizing effect of the products, replacing traditional chemical thickeners to create natural green beauty products.

5. Industrialization challenges and future development prospects

Although nanocellulose has huge application potential, it is still in a critical breakthrough period for large-scale application worldwide and faces three core challenges: First, some preparation processes are energy-intensive and cost-prohibitive, which restricts large-scale popularization; second, the stability control of high-solid-content nanocellulose dispersions is difficult, and re-dispersibility after drying is poor; third, the industry standard system is imperfect, and product performance of different manufacturers varies greatly, which affects downstream application adaptation.

In the future, the nanocellulose industry will develop rapidly in three major directions: first, process optimization, focusing on low-energy, continuous, and green preparation technologies to reduce production costs and improve product uniformity; second, functional customization, through precise surface modification, develop special nanocellulose products to adapt to emerging fields such as high-end medical, new energy, electronic materials, etc.; third, industrial chain collaboration, open up the entire chain of agricultural and forestry waste raw material supply, large-scale production, and downstream applications, improve industry standards, and promote the transition from laboratory to industrial mass production. Nanjing Tianlu Nano also keeps up with the development trend of the industry. On the one hand, it continues to delve into the preparation technology of highly dispersible nanocellulose and functional modification (carboxylation /interface control) technology. On the other hand, it focuses on the construction of highly stable suspension systems, precise control of rheological properties and optimization of multi-industry application formulas. It is committed to providing customers with a full range of application solutions. At the same time, it continues to expand product application boundaries, promote the widespread application of nanocellulose in all walks of life, and help the industry's green transformation and high-quality development.

Conclusion

As a model of the integration of natural biomass and nanotechnology, nanocellulose breaks the industry pain points of weak performance of traditional green materials and non-environmental protection of synthetic high-performance materials. It is not only an effective way to solve the resource utilization of agricultural and forestry waste, but also the core carrier to realize the green transformation of the materials industry. With the continuous breakthroughs in preparation technology, the continuous reduction of costs and the continuous expansion of application scenarios, nanocellulose will gradually replace some petroleum-based materials and become the core pillar of the future green materials industry, injecting strong impetus into the realization of global carbon neutrality goals and sustainable development.