Microcapsule Shell Oxygen Barrier via Polyelectrolyte Multilayers

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Solution Overview

Problem

Microcapsules face challenges in preventing oxygen and moisture exposure, leading to chemical changes in sensitive core materials, which existing technologies fail to adequately address.

Innovation Solution

The method involves forming microcapsules with a shell encapsulating a core material, using layer-by-layer deposition of polyelectrolytes, alternating between organic and inorganic polyelectrolytes to create a barrier that reduces oxygen transfer rates and enhances stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a single shell layer is used to encapsulate core material, then manufacturing simplicity is maintained, but oxygen and moisture barrier performance is insufficient

Engineering Contradiction:

Improveoxygen and moisture barrier performanceVSAvoidshell structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies composite materials by combining organic polyelectrolyte layers with inorganic polyelectrolyte layers to form an alternating multilayer structure. This composite approach leverages the complementary properties of both material types - the organic layers provide flexibility and biocompatibility while the inorganic layers enhance barrier performance against oxygen and moisture, thereby resolving the contradiction between barrier performance and structural simplicity.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The shell structure is segmented into multiple alternating layers of organic and inorganic polyelectrolytes rather than using a single homogeneous layer. This segmentation allows each layer to contribute specific functional properties, with the inorganic layers providing enhanced barrier performance and the organic layers providing flexibility, thus improving overall barrier performance without excessive complexity.

Inventive Principle:

Principle #1Segmentation

2Reliability

If inorganic materials are added to enhance barrier performance, then oxygen transfer rates are reduced, but manufacturing process complexity increases

Engineering Contradiction:

Improveoxygen transfer rate reductionVSAvoidlayer-by-layer deposition process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses charged polyelectrolyte layers as intermediary structures that facilitate the incorporation of inorganic materials. The alternating charged layers provide electrostatic interactions that enable controlled deposition of inorganic polyelectrolytes, creating a manageable manufacturing process while achieving enhanced barrier performance through the intermediary layered structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent employs parameter changes by alternating the charge characteristics and material composition between layers. By changing the parameters of the polyelectrolyte layers (charge density, thickness, composition) in an alternating pattern, the process achieves controlled incorporation of inorganic materials while maintaining manufacturability through systematic parameter variation rather than complex process requirements.

Inventive Principle:

Principle #35Parameter changes

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 approach effectively reduces oxygen transfer rates and minimizes agglomeration, providing a robust barrier that protects sensitive ingredients from environmental degradation, maintaining desired physical and chemical properties.

Implementation Method 1

layer-by-layer deposition of polyelectrolytes, alternating between organic and inorganic polyelectrolytes to create a barrier

Methodology Applied

Scientific EffectElectrostatic attraction: Electrostatics

Data Source

PatentUS8557382B2Layer by layer modification of microcapsules with inorganic materials

Publication Date: 2013.10.15 SOUTHWEST RES INST

AI summary

The present disclosure relates to a microcapsule and a method of forming a microcapsule which may be used for oxygen sensitive materials. The microcapsule may comprise a shell encapsulating a core material having a surface, wherein the shell comprises a first organic or inorganic polyelectrolyte providing a plurality of cationic or anionic charges. This may then be followed by forming a first layer comprising an inorganic or organic polyelectrolyte on the microcapsule surface, where the polyelectrolyte of the first layer provides a plurality of cationic or anionic charges, opposite to the charge of the shell polyelectrolyte. This may then be followed by forming a second layer comprising a second organic or inorganic polyelectrolyte providing a plurality of cationic or anionic charges, opposite to the charge of the first layer polyelectrolyte.