SWCNT Polyelectrolyte Liquid Crystals via Crown Ether Solubility

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The limited solubility of single-walled carbon nanotube (SWCNT) polyelectrolytes prevents the formation of liquid crystalline phases, hindering the production of ordered macroscopic materials with superior mechanical and electrical properties.

Innovation Solution

The use of crown ethers to increase solubility by capturing counterions and promoting charge repulsion among SWCNTs, combined with high-speed mixing, allows for the formation of SWCNT polyelectrolyte solutions up to 52 mg/mL in a liquid crystalline phase, enabling the production of strong and conductive fibers and composites without the need for polymers or additives.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If conventional solvents are used for SWCNT polyelectrolytes, then the solubility is limited, but the concentration cannot reach the level needed to form liquid crystalline phases

Engineering Contradiction:
Improveconcentration of SWCNT polyelectrolyteVSAvoidsolubility of SWCNT polyelectrolyte
Core Design Contradiction:
Quantity of substanceVSEase of manufacture

Solution Approach 1:

The patent changes the chemical parameter of the solvent system by introducing crown ethers (specifically 18-crown-6) as complexing agents. This chemical modification enables the formation of soluble complexes between crown ethers and alkali metal counterions, thereby increasing the solubility of SWCNT polyelectrolytes and enabling concentrations up to 52 mg/mL to be achieved, which is sufficient for liquid crystalline phase formation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

Crown ethers act as intermediary substances that mediate between the SWCNT polyelectrolytes and the solvent system. The crown ethers complex with alkali metal counterions, creating soluble intermediates that facilitate the dissolution of SWCNT polyelectrolytes at high concentrations without requiring extreme conditions or complex processing.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If high concentration is achieved to form liquid crystalline phase, then ordered macroscopic materials can be produced, but the solubility limitation prevents reaching such concentrations

Engineering Contradiction:
Improveliquid crystalline phase formationVSAvoidconcentration of SWCNT polyelectrolyte
Core Design Contradiction:
Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The patent modifies the chemical environment by adding crown ethers, which changes the solubility parameters of the system. This parameter change enables the formation of liquid crystalline phases at concentrations up to 52 mg/mL by creating stable soluble complexes that prevent precipitation and maintain phase stability at high concentrations.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a composite solvent system comprising multiple components: crown ethers, alkali metals, polyaromatic compounds, and aprotic solvents. This composite system works synergistically to achieve both high solubility and liquid crystalline phase formation, with each component contributing specific functions to the overall system performance.

Inventive Principle:
Principle #40Composite materials

3Ease of manufacture

If simple mixing is used, then the process is simple, but the solubility and liquid crystalline phase formation are prevented

Engineering Contradiction:
Improveprocess simplicityVSAvoidliquid crystalline phase formation
Core Design Contradiction:
Ease of manufactureVSStability of the object's composition

Solution Approach 1:

The patent incorporates preliminary actions in the form of pre-synthesis steps where SWCNT polyelectrolytes are first prepared with alkali metal functional groups, then dried under vacuum. These preliminary preparations create the necessary conditions for subsequent liquid crystalline phase formation upon addition of crown ethers and aprotic solvents, ensuring phase stability without complex processing during the main manufacturing step.

Inventive Principle:
Principle #10Preliminary action

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 results in SWCNT fibers with tensile strength of 124 MPa and Young's modulus of 14 GPa, and conductive composites with improved mechanical and electrical properties, surpassing previous methods in terms of fiber quality and production simplicity.

Implementation Method 1

The use of crown ethers to increase solubility by capturing counterions and promoting charge repulsion among SWCNTs

Methodology Applied
Scientific EffectComplexation:

Implementation Method 2

mixing the single-walled carbon nanotube polyelectrolytes with a polar aprotic solvent to form a mixture, where the mixing results in the formation of single-walled carbon nanotubes in the liquid crystalline phase

Methodology Applied
Scientific EffectTurbulence: Turbulence

Implementation Method 3

The formation of a liquid crystalline single-walled carbon nanotube phase is preferred in order to manufacture single-walled carbon nanotube polyelectrolytes into ordered macroscopic materials

Methodology Applied
Scientific EffectLiquid crystalline phase: Liquid Crystals

Implementation Method 4

coagulating the mixture to form the single-walled carbon nanotube fibers

Methodology Applied
Scientific EffectCoagulation: Coagulation

Data Source

PatentUS9249023B2Liquid crystals from single-walled carbon nanotube polyelectrolytes and their use for making various materials
Publication Date: 2016.02.02 WILLIAM MARCH RICE UNIVERSITY

AI summary

In some embodiments, the present disclosure pertains to methods of forming a solution of single-walled carbon nanotube polyelectrolytes in a liquid crystalline phase. In some embodiments, such methods comprise: (a) providing single-walled carbon nanotube polyelectrolytes; and (b) mixing the single-walled polyelectrolytes with a polar aprotic solvent to form a mixture, where the mixing results in the formation of single-walled carbon nanotubes in the liquid crystalline phase. In some embodiments, the polar aprotic solvent comprises crown ether. In some embodiments, the present disclosure pertains to a method of making single-walled carbon nanotube fibers. Further embodiments of the present disclosure pertain to a method of making a single walled carbon nanotube composite. In some embodiments, the present disclosure pertains to an article comprising neat aligned carbon nanotubes.