Core-shell biodegradable microparticles with metal oxide shell
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing cosmetic microparticles are either non-biodegradable and agglomerate, or biodegradable but hydrophobic and difficult to disperse in aqueous products, making them unsuitable for sustainable and effective use in cosmetics.
Innovation Solution
Development of core-shell particles with a thermoplastic polyester core and a partially water-wettable metal oxide shell, where the shell is permanently attached, allowing for biodegradability and amphiphilic properties that enable dispersion in both polar and nonpolar solvents without additional additives.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If biodegradable thermoplastic polyester particles are used, then environmental sustainability is improved, but dispersibility in aqueous media deteriorates due to hydrophobicity
Solution Approach 1:
The invention applies local quality by creating a core-shell structure where the core maintains hydrophobic biodegradable polyester properties while the shell provides hydrophilic metal oxide surface properties. This localized differentiation allows the particle interior to remain biodegradable while the surface enables aqueous dispersibility without requiring the bulk material to be hydrophilic.
Solution Approach 2:
The invention uses composite materials by combining biodegradable thermoplastic polyester with hydrophilic metal oxide particles to create a core-shell composite structure. This composite approach allows the particle to exhibit both biodegradability from the polyester core and aqueous dispersibility from the metal oxide shell, resolving the contradiction between these two properties.
2Adaptability or versatility
If hydrophobic surface treatment is applied to improve dispersibility in organic media, then amphiphilic character is improved, but biodegradability deteriorates due to persistent hydrophobic coating
Solution Approach 1:
The invention applies parameter changes by selecting metal oxide particles with specific surface properties (methanol value between 5-25) that provide moderate hydrophobicity rather than strong hydrophobicity. This parameter optimization allows the particles to achieve amphiphilic character for dispersibility in both polar and nonpolar solvents while maintaining sufficient biodegradability, as the metal oxide shell degrades over time unlike persistent hydrophobic coatings.
3Stability of the object's composition
If metal oxide shell is permanently attached to provide stability, then structural integrity is improved, but dissolution and biodegradation deteriorate
Solution Approach 1:
The invention applies the flexible shells principle by using a thin metal oxide shell that provides structural integrity and surface properties while remaining permeable to water and enzymes. The shell is thin enough to allow degradation processes to penetrate and act on the polyester core, enabling biodegradation while still providing the stability and dispersibility benefits of a permanent coating.
4Reliability
If uncoated thermoplastic polyester particles are used to maintain biodegradability, then environmental friendliness is improved, but agglomeration tendency worsens
Solution Approach 1:
The invention applies local quality by concentrating the anti-agglomeration function in the metal oxide shell while keeping the polyester core simple and biodegradable. The shell provides surface charge and steric hindrance that prevent agglomeration, while the core maintains biodegradability, resolving the contradiction between these two requirements.
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 core-shell particles are readily biodegradable, maintain amphiphilic properties during dispersion, and have improved oil absorbency, addressing the limitations of existing particles by being environmentally friendly and effectively dispersible.
Implementation Method 1
the thermoplastic polyester (C) is heated to above its melting range, and accordingly becomes free-flowing
Implementation Method 2
The core-shell particles (A) of the invention are amphiphilic, that is to say they are both hydrophilic (i.e. water-loving) and lipophilic (i.e. fat-loving)
Implementation Method 3
the particles (E) become attached to the surface of the polyester particles (C), forming the core-shell particles (A)
Data Source
AI summary
Core-shell particles and processes for producing the same. Where the core-shell particles include a core (B) and a shell (D). The core (B) includes a thermoplastic polyester (C) with a melting range of lower than 160° C. and the shell (D) includes partially water-wettable particles (E) of metal oxide. Where the partially water-wettable particles (E) have a methanol value of less than 30 and the metal content of the core-shell particles (A) is at least 2.5% by weight.