Cellulose Fiber Heat Storage via In-Situ Phase Change Encapsulation
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Solution Overview
Problem
Current methods for incorporating phase change materials into cellulose fibers require separate encapsulation and face limitations such as limited availability of microcapsules, instability of phase change materials, and inability to create permanent bonds between PCM and the cellulose matrix, which hinders efficient heat storage and controlled release of active ingredients.
Innovation Solution
A direct process involving in-situ encapsulation of non-polar organic compounds into a cellulose spinning solution using tertiary amine oxide and nanoscale hydrophobic particles to form stable emulsions, allowing for the production of cellulosic moldings with enhanced heat storage capacity and controlled release of active ingredients.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If phase change materials are encapsulated separately and incorporated into cellulose fibers, then the heat storage capacity can be increased, but the manufacturing process becomes more complex and the availability of suitable microcapsules is limited
Solution Approach 1:
The patent combines the encapsulation of phase change materials with the cellulose fiber formation process itself. The phase change material is incorporated into the spinning solution along with cellulose, and both are processed together through the dry-wet extrusion process, eliminating the need for separate encapsulation steps and reducing manufacturing complexity
Solution Approach 2:
The phase change material is prepared in advance as a non-polar organic compound that can be directly incorporated into the spinning solution. The cellulose is dissolved in tertiary amine oxide before adding the phase change material, so that both components are ready for simultaneous processing through the extrusion apparatus
2Use of energy by moving object
If phase change materials are incorporated into polyolefin matrices, then the heat storage capacity increases, but the method cannot be directly applied to cellulose due to compatibility issues
Solution Approach 1:
The patent uses tertiary amine oxide as an intermediary solvent to dissolve cellulose and create a compatible spinning solution. This intermediary medium allows the non-polar phase change material to be incorporated with the polar cellulose, bridging the compatibility gap between these two materials with different chemical properties
Solution Approach 2:
The patent changes the physical and chemical parameters of the spinning solution by using tertiary amine oxide as a solvent system. This parameter change enables the incorporation of non-polar organic compounds into the cellulose matrix by adjusting the polarity and solubility characteristics of the dissolution medium
3Stability of the object's composition
If non-polar organic compounds are added to cellulose spinning solution, then permanent inclusions can be formed, but the viscosity of the solution increases
Solution Approach 1:
The patent changes the viscosity parameter of the spinning solution by controlling the concentration of non-polar organic compounds and adjusting the tertiary amine oxide to cellulose ratio. This parameter optimization allows sufficient inclusions to be formed while maintaining the solution's processability and preventing excessive viscosity
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
The process significantly increases heat storage capacity and enables controlled release of non-polar active ingredients, eliminating the need for prefabricated capsules and layer structures, while allowing for precise adjustment of melting points and broader application in textiles and medical/cosmetic uses.
Implementation Method 1
the viscosity of the non-polar material is increased so that it can be emulsified in the water-containing cellulose/amine oxide solution
Implementation Method 2
the viscosity of the non-polar material is increased so that it can be emulsified
Implementation Method 3
nanoscale, flat, hydrophobic particles are added to the emulsion, which envelop the droplets of the non-polar organic compound
Implementation Method 4
the suspension is formed and the cellulose is recrystallized, whereby shaped bodies with a cellulose matrix are obtained
Implementation Method 5
a shaping polymer is combined with an organic phase change material that can exchange energy with the environment through melting/solidification transition
Implementation Method 6
The amount of energy exchange and the effective temperature range correlate with the chemical structure, the change in physical enthalpy and the concentration of the phase change material
Data Source
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AI summary
The invention relates to a method for producing functional molded cellulose articles comprising very finely distributed embedded covalent organic compounds and mixtures according to a dry-wet extrusion process. The molded articles produced by means of said method have a significantly greater storage capacity for heat and/or covalent active substances than unmodified cellulose fibers. Said molded articles are particularly suitable for use in fabrics for clothing, technical fabrics, leisure, medicine, and cosmetics. The functional effect can refer to the physical heat storage effect or the uniform and finely dosed storage and release of covalent active substances and plant extracts from the interior of the fibers. By adequately selecting the covalent concentration, said method also makes it possible to produce fibers that can absorb liquid or gaseous covalent substances.