Pre-Oxidized 3D-Printed Polymer Monoliths for Shape-Stable Carbonization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for fabricating carbon-based trace-contaminant sorbents face challenges with polymer monolith meltdown and shape distortion during thermal treatment due to the use of thermoplastic polymers that swell and melt during carbonization, necessitating complex support structures that are cumbersome to redesign and can damage the monolith.
Innovation Solution
A method involving pre-oxidation of polymer monoliths at temperatures below the melting point to set the monolith structure, followed by carbonization and optional activation, which preserves shape and creates a microporous sorbent with high surface area and porosity, eliminating the need for complex support structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If thermoplastic polymers are used for 3D-printed monoliths, then ease of manufacture is improved, but shape stability during thermal treatment deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-oxidizing the polymer monolith at a temperature below the melting point before carbonization. This pre-oxidation step sets the monolith structure in advance, preventing swelling and melting during the subsequent high-temperature carbonization process, thus resolving the shape stability issue while maintaining ease of manufacture
Solution Approach 2:
The patent changes the physical and chemical parameters of the polymer monolith through pre-oxidation treatment. By exposing the monolith to oxygen at controlled temperatures below the melting point, the polymer structure is modified to gain thermal stability, allowing it to withstand the carbonization process without deforming
2Stability of the object's composition
If structural supports are used to prevent polymer melting, then shape stability is improved, but device complexity increases
Solution Approach 1:
The patent extracts and eliminates the need for structural supports by applying pre-oxidation treatment to the polymer monolith. The pre-oxidation process inherently prevents melting and shape loss, making external support structures unnecessary and simplifying the overall fabrication process
Solution Approach 2:
The patent enables the polymer monolith to serve itself by applying pre-oxidation that inherently prevents melting and shape distortion during carbonization. The monolith's own structure is modified to gain thermal stability, eliminating the need for external support structures
3Stability of the object's composition
If structural supports are used during carbonization, then shape stability is improved, but manufacturing precision deteriorates due to potential damage
Solution Approach 1:
The patent removes the structural supports from the process by using pre-oxidation to prevent melting. This eliminates the risk of support structures damaging the monolith during removal after carbonization, thereby improving manufacturing precision while maintaining shape stability
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 method ensures shape retention and enhances sorption capacity, achieving efficient trace-contaminant removal with simplified fabrication and improved monolith integrity, meeting NASA's requirements for space applications.
Implementation Method 1
pre-oxidizing the polymer monolith in a flow of an oxidizing gas at a temperature below the melting point of the polymer precursor
Implementation Method 2
pre-oxidizing the polymer monolith in a flow of an oxidizing gas at a temperature below the melting point of the polymer precursor
Implementation Method 3
carbonizing the pre-oxidized polymer monolith, so as to produce a carbon monolith, by exposure to elevated temperatures in a non-oxidative atmosphere
Data Source
AI summary
High purity carbon sorbent monoliths, particularly effective for the removal of trace-contaminants such as ammonia, formaldehyde, and methyl mercaptan from a gas flow, are fabricated by 3D-printing polymer monoliths, pre-oxidizing them in a flow of air at a temperature below the melting point of the polymer precursor, carbonizing them, and subsequently activating them to a weight loss of about 20 percent. The pre-oxidation step effectively prevents polymer-monolith swelling and melting during carbonization.