Modified Nanocellulose Oxidation With Low-Toxicity Functionalization
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Solution Overview
Problem
Current methods for producing nanocellulose from renewable biomass involve the use of toxic chemicals and generate significant chemical waste, limiting its application in biological and biomedical fields due to safety and environmental concerns.
Innovation Solution
A catalytic oxidation process using an iron-organic acid complex and hydrogen peroxide to produce carboxylic acid-containing microcellulose or nanocellulose, followed by a catalytic cellulose cleavage process to reduce particle size and introduce additional functional groups such as amines or amino acids, allowing for the creation of modified nanocellulose derivatives with enhanced biomedical applications.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If acid hydrolysis using concentrated strong acids is used to produce nanocellulose, then nanocellulose with rod-like shape and high crystallinity is obtained, but toxic chemical waste is generated and costly purification is required
Solution Approach 1:
The patent changes the chemical parameters of the oxidation process by using diluted hydrogen peroxide (3-30% concentration) instead of concentrated strong acids, and employs an iron-organic acid complex catalyst system to achieve selective oxidation of cellulose to carboxylic acid-containing nanocellulose with controlled particle size and morphology while minimizing toxic waste generation
Solution Approach 2:
The patent replaces the mechanical homogenization step required in traditional methods with a chemical oxidation approach using iron-organic acid complex and hydrogen peroxide, which directly breaks down cellulose into nanocellulose particles through controlled oxidation, eliminating the need for high-pressure homogenization and reducing energy consumption
2Shape
If TEMPO/bleach/NaBr oxidation process is used to produce nanocellulose, then cellulose nanofibrils with whisker-type shape are obtained, but toxic halogenated by-products are generated and manufacturing capability is limited
Solution Approach 1:
The patent extracts and eliminates the toxic components (TEMPO, bleach, and NaBr) from the oxidation system, replacing them with an environmentally friendly iron-organic acid complex catalyst and hydrogen peroxide oxidant, thereby producing nanocellulose without generating halogenated by-products while maintaining effective oxidation capability
Solution Approach 2:
The patent uses inexpensive and environmentally benign materials such as iron salts, organic acids, and diluted hydrogen peroxide as oxidants, replacing expensive and toxic chemicals like TEMPO and bleach, making the process more sustainable and suitable for large-scale manufacturing
3Quantity of substance
If high pressure homogenization is used to mechanically break-down cellulose, then cellulose nanofibrils are produced, but energy consumption is high and laborious separation procedure is required
Solution Approach 1:
The patent replaces the high-energy mechanical homogenization process with a chemical oxidation system using iron-organic acid complex and hydrogen peroxide, which chemically breaks down cellulose into nanocellulose particles through controlled oxidation, significantly reducing energy consumption and simplifying the separation procedure
Solution Approach 2:
The patent changes the processing parameters from high-pressure mechanical treatment to mild chemical oxidation conditions, using diluted hydrogen peroxide and iron catalyst at lower pressures and temperatures, thereby reducing energy consumption while achieving effective nanocellulose production with simplified separation
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This method produces nanocellulose with reduced particle size and enhanced functionalization, minimizing chemical waste and toxicity, thereby enabling safer and more sustainable production suitable for biomedical applications without the need for intensive purification.
Implementation Method 1
contacting an unmodified cellulose at a temperature with an oxidation composition for a period to produce an oxidized cellulose, wherein the oxidation composition comprises an iron-organic acid complex and hydrogen peroxide
Implementation Method 2
the oxidation composition comprises an iron-organic acid complex and hydrogen peroxide
Implementation Method 3
contacting an oxidized cellulose with a cleavage composition at a temperature for a period to form an oxidized nanocellulose, wherein the cleavage composition comprises an iron-organic complex and hydrogen peroxide
Implementation Method 4
contacting the oxidized cellulose or the oxidized nanocellulose with a modification composition at a second temperature to form a modified cellulose or modified nanocellulose, wherein the modification composition comprises (a) a modification agent and (b) an acid
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
This invention discloses methods for producing modified cellulose, modified nanocellulose, modified nanocellulose functionalized with other functional species, and derivatives thereof. The present invention also provides cellulose, nanocellulose, and their derivatives that are safe to use inside an animal or human body and are biocompatible without costly purification. These cellulose or nanocellulose materials can be used in many different applications, including carrier for pharmaceutical active agents and other medical devices.