Stabilizing Janus Nanosheets in High-Salt Brine

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Maintaining colloidal stability of graphene-based amphiphilic Janus nanosheets in high salt content environments while retaining surface chemical properties is challenging, as they tend to aggregate and precipitate in salt water with high ionic strength, limiting their application in oil recovery and other processes.

Innovation Solution

Stabilizing graphene-based amphiphilic Janus nanosheets in high-salt brine using poly(sodium 4-styrenesulfonate) (PSS) to create a stable nanofluid that maintains interfacial behavior and self-assembly capabilities, even at elevated temperatures, by generating electrosteric repulsive interactions and forming an elastic film at the oil/brine interface.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If graphene-based amphiphilic Janus nanosheets are dispersed in salt water with high ionic strength, then the application in oil recovery and other processes is limited, but the nanosheets aggregate and precipitate

Engineering Contradiction:

Improveapplication in oil recoveryVSAvoidcolloidal stability

Core Design Contradiction:

Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The patent introduces poly(sodium 4-styrenesulfonate) (PSS) as a mediator between the graphene-based amphiphilic Janus nanosheets and the high-salt brine environment. PSS adsorbs onto the nanosheet surfaces and provides electrosteric stabilization, preventing aggregation while allowing the system to function in high-salinity conditions required for oil recovery applications.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent modifies the surface charge density and zeta potential of the nanosheets by controlling the concentration and molecular weight of PSS. This parameter change enables the nanosheets to maintain colloidal stability across a range of salt concentrations, including high-salinity brines, while preserving their interfacial activity for oil recovery.

Inventive Principle:

Principle #35Parameter changes

2Stability of the object's composition

If poly(sodium 4-styrenesulfonate) (PSS) is used to stabilize nanosheets in high-salt brine, then colloidal stability is maintained, but the system complexity increases

Engineering Contradiction:

Improvecolloidal stabilityVSAvoidsystem complexity

Core Design Contradiction:

Stability of the object's compositionVSDevice complexity

Solution Approach 1:

The patent applies PSS selectively to the surface of the nanosheets rather than throughout the entire system. This localized application provides stabilization exactly where needed at the nanosheet surface, minimizing the amount of polymer required and reducing overall system complexity while maintaining colloidal stability.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent creates a composite structure where PSS forms an outer layer on the graphene-based nanosheets. This composite architecture combines the interfacial activity of the nanosheets with the stabilizing properties of the polyelectrolyte, achieving colloidal stability in high-salt environments without requiring complex stabilization mechanisms.

Inventive Principle:

Principle #40Composite materials

3Stability of the object's composition

If nanosheets are stabilized in fresh water, then colloidal stability is achieved, but the need for fresh water increases and waste water treatment cost increases

Engineering Contradiction:

Improvecolloidal stabilityVSAvoidfresh water consumption

Core Design Contradiction:

Stability of the object's compositionVSQuantity of substance

Solution Approach 1:

The patent converts the previously harmful high-salt environment into a beneficial feature by demonstrating that PSS-stabilized nanosheets not only survive but thrive in high-salinity brines. This eliminates the need for fresh water and allows direct use of produced water or formation water, turning a waste disposal problem into a resource advantage.

Inventive Principle:

Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The stabilized nanofluid system is designed to be self-sufficient in high-salinity environments, using the brine itself as the dispersing medium rather than requiring fresh water. This self-service capability allows the system to operate autonomously in oil reservoirs without external water supplies, reducing both fresh water consumption and waste water treatment requirements.

Inventive Principle:

Principle #25Self-service

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 effectively stabilizes graphene-based amphiphilic Janus nanosheets in high-salt conditions, allowing them to maintain interfacial behavior and form elastic films, enhancing oil recovery and reducing the need for fresh water, thus being environmentally beneficial and cost-effective.

Implementation Method 1

by generating electrosteric repulsive interactions

Methodology Applied

Scientific EffectElectrosteric repulsion:

Implementation Method 2

forming an elastic film at the oil/brine interface

Methodology Applied

Scientific EffectInterfacial film formation: Surfactant

Data Source

PatentUS11891304B2Method of preparing a stable nanofluid of amphiphilic Janus nanosheets in salt water

Publication Date: 2024.02.06 UNIV HOUSTON SYST

AI summary

A stable water based nanofluid of graphene-based amphiphilic Janus nanosheets, where the nanofluid has a high salt-content while retaining the interfacial activities of the nanosheets. Such a nanofluid of amphiphilic Janus nanosheets may be used for enhanced oil recovery.