Sulfonated Polyester Composite Powders with Silver Nanoparticles
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Solution Overview
Problem
There is a need for antibacterial composite materials suitable for selective laser sintering (SLS) applications, as traditional materials can harbor bacterial growth due to their layered construction, which is not adequately sterilized by washing, posing risks in medical and food industry applications.
Innovation Solution
Development of a composite powder comprising a sulfonated polyester matrix with dispersed silver nanoparticles coated in a polymer shell, which inhibits bacterial growth through controlled release of silver ions, synthesized using an environmentally friendly process without organic solvents, ensuring effective dispersion and stability of nanoparticles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If traditional SLS materials are used, then the printing process is simple, but bacterial growth is promoted due to layered construction
Solution Approach 1:
The patent creates a composite powder system combining sulfonated polyester matrix with dispersed silver nanoparticles, forming a core-shell structure where the core contains the polymer matrix with embedded AgNPs and the shell provides additional protective and functional properties. This composite approach enables antibacterial functionality while maintaining SLS processability.
Solution Approach 2:
The invention implements local quality by concentrating silver nanoparticles specifically within the polymer matrix structure, creating regions of high antibacterial activity at the particle level while maintaining overall material homogeneity suitable for SLS processing. The core-shell structure further refines this by localizing different functions in different regions.
2Object-affected harmful factors
If silver nanoparticles are added to provide antibacterial properties, then bacterial inhibition is improved, but nanoparticle agglomeration occurs reducing effectiveness
Solution Approach 1:
The patent controls nanoparticle dispersion by carefully managing parameters including silver nanoparticle concentration (0.1-10 wt%), particle size (10-100 nm), and polymer matrix composition. The sulfonated polyester structure with specific functional groups is designed to interact with silver nanoparticles at the molecular level, preventing agglomeration through steric and electrostatic stabilization.
Solution Approach 2:
The sulfonated polyester matrix acts as an intermediary between silver nanoparticles and the external environment, providing a stable dispersion medium that prevents nanoparticle aggregation. The polymer chains and functional groups serve as spacing elements that maintain uniform distribution of AgNPs throughout the material.
3Reliability
If a polymer shell is added to coat silver nanoparticles, then stability and resistance are improved, but manufacturing complexity increases
Solution Approach 1:
The patent merges the core particle formation and shell polymerization into a single integrated process. The core sulfonated polyester matrix with embedded silver nanoparticles is formed first, then the shell polymer is grown directly onto this core in situ through polymerization reactions, eliminating the need for separate coating steps and simplifying manufacturing.
Solution Approach 2:
The core particle structure with sulfonated polyester matrix and dispersed silver nanoparticles is prepared in advance before shell formation. This preliminary core structure provides a stable foundation that directs subsequent shell polymerization, ensuring uniform coating and simplifying the overall manufacturing sequence.
4Manufacturing precision
If fine powder particles are used for detailed SLS printing, then printing precision is improved, but bacterial harboring in crevasses increases
Solution Approach 1:
The silver nanoparticles embedded in the polymer matrix provide self-service antibacterial protection at the micro-scale where bacteria would normally colonize. The fine powder particles maintain printing precision while the distributed AgNPs throughout the material structure provide continuous antibacterial activity in areas that would otherwise be prone to bacterial harboring.
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 composite powder effectively inhibits bacterial growth, providing enhanced antibacterial properties for SLS applications, maintaining chemical and mechanical stability while minimizing nanoparticle agglomeration, and offering improved thermal and acid/base resistance.
Implementation Method 1
adding a solution of a reducing agent to the mixture, thereby forming an emulsion of particles comprising a sulfonated polyester matrix and a plurality of silver nanoparticles disposed within the sulfonated polyester matrix
Implementation Method 2
adding a styrene monomer and initiator to the emulsion of composite particles to form a shell polymer disposed about the core particles
Implementation Method 3
aggregating the emulsion of particles to form aggregated particles
Implementation Method 4
coalescing the aggregated particles to form coalesced particles
Data Source
AI summary
A composite powder includes a core particle comprising a sulfonated polyester matrix and a plurality of silver nanoparticles dispersed within the matrix, and a shell polymer disposed about the core particle, and methods of making thereof. Various articles can be manufactured from such composite powders.