Work

Microwave-tailored biochar-based graphene oxide in LLDPE composites for reinforcement and fouling resistance

Year: 2026

Type: article

Abstract: Biochar-based graphene oxide (BBGO) is a promising biomass-derived filler for multifunctional melt-processed polyolefins, but it remains unclear whether a single synthesis variable can generate distinct BBGO states and thereby separate bulk and surface functions after compounding. Here, corn-stalk-derived biochar was converted into BBGO by ZnCl 2 -assisted microwave pyrolysis and compounded with linear low-density polyethylene (LLDPE) through solvent-free melt extrusion. The study examined how microwave power governs BBGO oxygen functionality, porosity, and the Raman-resolved evolution of its defect-rich carbon framework, and how these coupled changes affect tensile reinforcement and early-stage fouling resistance in extruded sheets. Increasing microwave power from 0.8 to 1.2 kW raised Brunauer-Emmett-Teller (BET) surface area from 219.73 to 401.85 m 2 /g and decreased oxygen content from 31.30 to 23.99 wt%. In the LLDPE series, 5 wt% BBGO synthesized at 1.0 kW gave the highest measured mean tensile response, increasing tensile strength and Young's modulus to 27.19 MPa and 1.32 GPa, respectively, compared with 12.43 MPa and 0.66 GPa for neat LLDPE. By contrast, 5 wt% BBGO synthesized at 0.8 kW produced the most favorable combined exposed-surface state: it gave the lowest initial and post-exposure water contact angles among the 5 wt% formulations, lower surface roughness than the corresponding 1.0 and 1.2 kW formulations at the common 5 wt% loading, and the sparsest visible algal deposition after 30 days of continuous-flow exposure. These results show that the filler state giving the highest measured mechanical response is not the one that gives the most favorable combined surface response. Accordingly, the advance extends beyond selecting an optimal microwave setting: microwave power is shown to pre-program different downstream composite functions within an otherwise unchanged biomass-to-composite route. Maximum BET surface area alone did not predict the best composite response. Instead, separate design windows were identified for mechanical reinforcement and early-stage fouling resistance, providing a practical process-structure-property guideline for multifunctional melt-processed polyolefin composites.

Source: Composites Part B Engineering

DOI: 10.1016/j.compositesb.2026.114117

Authors: Jiahui Liu, Scarlett Allende, Yan Li, Changqing Fang, Mohan V. Jacob

Institutions: Southwest University, James Cook University, Xi'an University of Technology

Language: English

Topic: Polymer Science and Applications

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Responsible consumption and production

Open Access status: hybrid

Estimated APC paid: $5,210