Hydrophobic modified nanocellulose: solving the hydrophilic shortcomings and realizing efficient hydrophobic applications of green materials

Hydrophobic modified nanocellulose is a new functional green material specially developed to address the hydrophilic defects of native nanocellulose. The surface of native nanocellulose is rich in free hydroxyl groups and is extremely hydrophilic. It is easy to absorb moisture, penetrate into water, and lose hydrophilicity at the interface. It cannot be adapted to industrial scenarios such as high humidity, waterproofing, and oily composites. Through the professional surface hydrophobic modification process, the hydrophilic characteristics of the surface of nanocellulose can be completely changed, giving the material stable, long-lasting, and controllable hydrophobic properties. It is currently the core solution in the field of new biomass materials to solve the problems of waterproofing and moisture-proofing, oil-water separation, and hydrophobic compatibility. It is widely used in various high-end industrial scenarios that require hydrophobic protection.

Nanjing Tianlu Nanotechnology Co., Ltd. is a high-tech enterprise rooted in Nanjing's science and technology innovation highland. It focuses on the green preparation, functional modification and large-scale mass production of nanocellulose. It has been deeply involved in the core technology of hydrophobic modification for many years, focusing on solving the problems of nanocellulose's hydrophilic shortcomings and industrial hydrophobic applications. Relying on its independent research and development process, standardized production base and professional R&D team, the company can customize the production of multi-level hydrophobic modified nanocellulose products. It has mature hydrophobic modification, stable mass production and scenario-based technology implementation capabilities, and provides customers in various industries with highly adaptable, long-term and stable hydrophobic nanocellulose overall solutions.

1. Hydrophilic disadvantages of native nanocellulose: core pain points in hydrophobic applications

The core application shortcoming of native nanocellulose is its strong hydrophilicity, which is also a key issue limiting its industrialization. The densely distributed hydroxyl groups on its molecular surface can quickly form hydrogen bonds with water molecules, resulting in the material having high wettability and high water absorption.

In practical applications, strong hydrophilic properties will cause many problems: the material is easy to absorb water and swell, the surface will seep and get damp, and the structural stability is poor in humid environments; it is not compatible with oily solvents and resin systems, and is prone to delamination and agglomeration during composite processing; it does not have waterproof, oil-proof, and anti-penetration capabilities, and it is completely unable to meet the hydrophobic use needs of industrial waterproofing, barrier, and self-cleaning. Therefore, hydrophobic modification has become a necessary link for the high-end industrialization of nanocellulose.。

2. Core principles of hydrophobic modification of nanocellulose

The core purpose of hydrophobic modification of nanocellulose is to completely eliminate the hydrophilic characteristics of the surface and build a stable hydrophobic surface layer without destroying the basic structure of the fiber. The technical principle is: through physical and chemical modification, the hydrophilic hydroxyl groups on the surface of nanocellulose are shielded, replaced and blocked, and at the same time, low surface energy hydrophobic groups such as silane groups, long-chain alkyl groups, and methyl groups are introduced on the fiber surface.

This technology can effectively block the hydrogen bonding channels of water molecules, significantly reduce the surface free energy of the material, and the nanocellulose from completely transform ' hydrophilic and water-absorbing ' to water-repellent, hydrophobic, impermeable and moisture-proof . At the same time, it retains the natural and completely biodegradable green properties of the material, achieving the unification of hydrophobic functions and environmentally friendly properties.

3. Industrial mainstream nanocellulose hydrophobic modification technology

Nanjing Tianlu Nanotechnology is deeply engaged in the field of industrialization of hydrophobic modified nanocellulose , breaking through the industry pain points of traditional modification processes such as high pollution, poor hydrophobic effect, insufficient durability, and unstable batches. Relying on a complete set of independent and controllable green modification technology systems, the hydrophobic modification process is low-consuming, environmentally friendly, and stable in mass production. At present, the company has mastered three major mainstream industrial hydrophobic modification technologies, which can accurately customize different gradients of hydrophobic effects according to customer scenario needs, comprehensively covering the needs of all scenarios such as civilian moisture-proofing, industrial high-strength hydrophobicity, and super-hydrophobic precision applications. The hydrophobic uniformity, stability, and durability of the products have all reached high-end industry standards.

1. Hydrophobic modification of silane coupling agent (industrial mainstream)

Through the covalent bond reaction between the silane coupling agent and the hydrophilic hydroxyl groups on the surface of nanocellulose, a dense and uniform siloxane hydrophobic coating layer is formed on the surface of the fiber, which greatly reduces the surface energy of the material and can achieve an ultra-high water contact angle of 110°–160°. The hydrophobic effect is stable, uniform, and has excellent adhesion. It is a core mass production process for industrial waterproofing, hydrophobic coatings, and barrier materials.

2. Esterification hydrophobic modification (highly durable hydrophobic solution)

Environmentally friendly organic acids, stearic acid and other reagents are used to esterify the hydroxyl groups on the fiber surface, grafting long-chain hydrophobic carbon groups to fully seal the hydrophilic active sites. The hydrophobic nanocellulose prepared by this process has extremely strong resistance to water washing, moisture resistance, and aging resistance. It has excellent hydrophobic durability and can be adapted to outdoor and high-humidity harsh working conditions for a long time.

3. Physical adsorption hydrophobic modification (safe and green hydrophobic solution)

Relying on lignin and environmentally friendly hydrophobic polymer additives, through physical adsorption . a natural hydrophobic protective layer is constructed on the surface of There is no chemical reaction, zero pollution, and no chemical residue in the entire process. The hydrophobic performance is mild and stable, and it is suitable for hydrophobic application scenarios with extremely high safety requirements such as food and medical care.nanocellulose

4. Advantages of hydrophobic properties of hydrophobic modified nanocellulose core

Compared with native hydrophilic nanocellulose, the core advantages of modified products are concentrated in the four dimensions of hydrophobicity, moisture-proof, impermeability, and compatibility, accurately solving the pain points of hydrophobic applications in the industry:

1. Extremely hydrophobic and water-repellent, anti-penetration and moisture-proof

Completely eradicates the defects of water absorption, water seepage and moisture return in virgin materials, and has excellent surface water-repellent properties. Water molecules cannot infiltrate or penetrate the surface of the material. In a high-humidity environment, the material does not absorb water, is not damp, and does not change its structure, which perfectly solves the industry problems of traditional biomass materials being afraid of water and having poor moisture resistance.

2. Oily system is hydrophobic and compatible, suitable for composite processing

The surface of modified nanocellulose is hydrophobic and can be evenly dispersed in various oily systems such as polyurethane, epoxy resin, acrylic resin, etc. It completely solves the problem of incompatibility between hydrophilic nanocellulose and oily materials and is prone to agglomeration and delamination, and provides core support for the processing of various hydrophobic composite materials.

3. Controllable hydrophobicity level and strong scene adaptability

Products with different levels of ordinary moisture-proof, high-strength hydrophobic, and super-hydrophobic can be accurately customized according to the needs of customer scenarios. The hydrophobic effect can be adjusted and customized to meet the differentiated hydrophobic needs of civil, industrial, and high-end precision scenarios.

4. The hydrophobic function is long-lasting and stable, and has excellent weather resistance.

The hydrophobic layer formed by the modification is firmly bonded and has the characteristics of resistance to water washing, friction, high and low temperature, and moisture aging. It will not fail or fall off after long-term use, and maintain stable hydrophobic, antifouling, and anti-penetration properties for a long time.

5. Application scenarios of hydrophobic modified nanocellulose core

Relying on exclusive, stable and controllable hydrophobic properties, hydrophobic modified nanocellulose is widely used in various industrial fields that require waterproofing, moisture-proof, oil-proof and impermeability. It is the core alternative product of green hydrophobic materials:

1. Fully degradable hydrophobic and moisture-proof packaging materials

In view of the pain points of traditional degradable packaging with poor waterproofing and susceptibility to moisture, fully biodegradable hydrophobic packaging films, moisture-proof substrates, and oil-proof packaging papers are prepared, which have excellent hydrophobic, oil-proof, moisture-proof and anti-permeability properties. They can be used for moisture-proof and hydrophobic packaging of food, medicine, and precision electronics, replacing traditional non-degradable plastic hydrophobic packaging.

2. Super hydrophobic antifouling protective coating

An environmentally friendly hydrophobic protective coating can be prepared and applied to the surface of wood, building materials, metals, and fabrics to form an ultra-thin hydrophobic protective film to achieve surface waterproofing, antifouling, and water penetration resistance. The coating is environmentally friendly, non-volatile, hydrophobic and self-cleaning, and is suitable for the hydrophobic protection needs of outdoor building materials, high-end home furnishings, and precision devices.

3. Hydrophobic lipophilic oil and water separation materials

Utilizing the modified nanocellulose hydrophobic and lipophilic properties of , we prepare hydrophobic aerogels and hydrophobic filtration membranes, which can efficiently adsorb and separate industrial oily wastewater and floating oil on the sea surface. They only absorb oil but not water. They have excellent hydrophobic isolation effects and can be recycled. They are green and environmentally friendly oil-water separation functional materials.

4. Industrial hydrophobic composite substrate

As a hydrophobic functional filler, it is added to various oily composite materials to enhance the overall waterproof, moisture-proof, and impermeability properties of the substrate, and improve the wet hydrophobic stability of the material. It is widely used in new energy substrates, outdoor composite materials, waterproof rubber and plastic products, and other fields.

5. Medical and textile hydrophobic functional substrates

It gives textile fabrics and medical substrates waterproof, oil-proof, and hydrophobic protective properties while retaining the breathable and degradable properties of the materials to create high-end hydrophobic functional fabrics and medical protective materials that are both safe and protective.

6. Industrial prospects of hydrophobic modified nanocellulose

In the context of the dual-carbon policy and the comprehensive implementation of the plastic ban, traditional chemical hydrophobic materials have disadvantages such as high pollution, difficulty in degradation, and non-environmental protection, and are gradually being eliminated by the market. Hydrophobic modified nanocellulose uses natural biomass as raw material and achieves stable hydrophobic function through green modification technology, which perfectly solves the industry contradiction that traditional green materials are not waterproof and traditional hydrophobic materials are not environmentally friendly .
As a core domestic enterprise specializing in the industrialization of hydrophobic nanocellulose, Nanjing Tianlu Nanotechnology continues to iterate on the core process of hydrophobic modification, optimize product hydrophobic stability and scene adaptability, break the application limitations of native nanocellulose, and use a full range of hydrophobic nanocellulose product systems that can be customized and mass-produced to empower waterproof packaging, functional coatings, environmentally friendly water purification, industrial compounding and other fields. It helps various industries achieve green and high-end upgrades of hydrophobic materials, and seizes the core track of new biomass functional new materials.