High hydrophobic poly(lactic acid) foams impregnating one-step Si-F modified lignin nanoparticles for oil/organic solvents absorption

In this work, the hydrophobic lignin nanoparticles (LNP) were synthesized by a synchronous modification of silanization and fluorination process. Thermogravimetric analyser, fourier-transform-infrared-spectroscopy, Xray photoelectron spectroscopy and transmission electron microscopy were used to confirm the surface modified LNP (m-LNP). The maximum degradation temperature of m-LNP was 85 degrees C higher than that of origin LNP. Then the bio-based PLA foams were prepared via freezing-dry method by impregnating various amount of m-LNP. The results showed that a high hydrophobicity (141 degrees of contact angle) and porosity structure (94% of porosity) were constructed when the m-LNP content increased to 6 wt% (PLA-6L). Afterwards, the absorption capacities of the PLA composite foams towards various oil/organic solvents are measured. The composite foams reached their saturated adsorption capacity in quite short time and exhibited good recyclability due to the two factors: high hydrophobicity and high porosity. Thus, the bio-based PLA/m-LNP composite foams could be used as the ecobenign and efficient absorbents for petroleum leakage, oil spills and toxic organic solvents in water contamination field.

Automated summary

The hydrophobic lignin nanoparticles (LNP) were synthesized through a synchronous modification process and used to prepare bio-based PLA foams with high hydrophobicity and porosity. These composite foams showed strong absorption capacities towards various oil/organic solvents and exhibited good recyclability.