Online Microfluidic Production of Sustainable Cyrene™-Derived Porous Microparticles

Abstract

The use of sustainable raw materials is now a necessity in all industries, including the production of porous microparticles. Cyrene™ is a cellulose-derived compound that is readily prepared through the reduction of the α,β-unsaturation of levoglucosenone (LGO)—a wood-based platform molecule. In this work, the importance of Cyrene™ as a potential bio-based molecule to produce sustainable porous microparticles is demonstrated. First, a methacrylic derivative of Cyrene™ (m-Cyrene) was synthesized. A microfluidic co-flow device was then established to produce m-Cyrene-based oil-in-water (O/W) controlled-size emulsions and to polymerize them by ultraviolet (UV) radiation in a vial. The continuous phase was a sodium dodecyl sulfate aqueous solution, and the dispersed phase was a mixture of m-Cyrene with methacrylic anhydride (MAN) at two different mass concentrations (i.e., 1 wt.% MAN and 92 wt.% MAN) and 2,2-dimethoxy-2-phenylacetophenone (DMPA) as a photoinitiator. The process used the lowest possible quantity of raw materials and avoided excessive purifications to produce homogeneous porous m-Cyrene-MAN microparticles. The controlled size and homogeneous size distribution of the produced polymer microparticles were confirmed by scanning electron microscope (SEM) images. The 3D microstructure as well as the porosity were determined using X-ray microtomography. The high-resolution 3D images produced indicate that the pores of the microparticles are homogeneous and that their porosity is controllable through the concentration of MAN in the monomer mixture (porosity of 30% for a 1 wt.% MAN ratio and 2% for a 92 wt.% MAN ratio). Such porosity control is very important for future potential encapsulation processes that require precise release control.

Microfluidics for Polymer Microparticles: Opinion on Sustainability and Scalability

“…m-Cyrene is derived from Cyrene™, a biobased solvent originating from cellulose feedstock, through transesterification in the presence of methacrylic acid [49]. In a recent study, polymer microparticles were synthesized with controlled porosity from m-Cyrene without using porogens and without changing the in situ UV polymerization method (P5) [33]. The porosity of the microparticle was measured with X-ray microtomography and modified by adding methacrylic anhydride (MAN), a chemical used as a precursor for the synthesis of methacrylate polymers, copolymers, and crosslinkers, to the dispersed phase in different concentrations.…”

Preparation and Application of Green Sustainable Solvent Cyrene

“…Adam et al calculated the interaction distances at equilibrium for different bacterial species and hydrophobic nanomaterials such as MoS 2 in two environmentally friendly solvents, water and Cyrene, and extended the Derjaguin, Landau, Verwey and Overbeek theory (DLVO theory) that describes the properties of nano-objects in solutions to the case of two-dimensional nanoflakes interacting with bacteria cell membranes, both for Gram-positive and Gram-negative bacteria [117]. Itawi et al demonstrated the importance of Cyrene™ as a potential bio-based molecule to produce sustainable porous microparticles [118]. Belharouak et al investigated a closed-loop recovery process to reclaim cathode materials, Al foils, and PVDF binder from cathode scraps using Cyrene.…”