A Scalable and Surfactant-Free Emulsion Method for Producing Microbeads from Varied Biomass Feedstocks

Area of Science:

• Materials Science
• Environmental Science
• Chemical Engineering

Background:

• Plastic microbeads in personal care and consumer products (PCCPs) contribute significantly to microplastic pollution.
• Existing regulations have not eliminated the use of plastic microbeads.
• Sustainable alternatives from biomass are hindered by processing challenges like limited solvents and high viscosity.

Purpose of the Study:

• To develop a method for producing biomass-derived microbeads suitable for PCCPs.
• To achieve microbead size (200-800 μm), shape, and mechanical properties comparable to plastic microbeads.
• To explore the use of cellulose and lignin as sustainable microbead precursors.

Main Methods:

• A surfactant-free emulsion/precipitation technique was employed.
• Biomass solutions in 1-ethyl-3-methylimidazolium acetate (EMImAc) were mixed with oils and precipitated using ethanol.
• Microbead characteristics were tuned by varying oil viscosity, interfacial tension, and biomass composition.

Main Results:

• Optimized protocols yielded >90% cellulose microbeads in the target size range.
• Kraft lignin was incorporated up to 20 wt % without surfactants.
• Microbead shape and surface morphology were successfully controlled by oil properties and biomass-interface interactions.

Conclusions:

• A viable method for producing sustainable biomass microbeads was established.
• The process allows for control over microbead size, shape, and mechanical properties.
• This approach offers a promising route to reduce microplastic pollution from PCCPs.