This article reports effective removal of methylene blue (MB) dyes from aqueous solutions using a novel magnetic polymer nanocomposite. The core-shell structured nanosorbents was fabricated via coating Fe3O4 nanoparticles with a layer of hydrogel material, that synthesized by carboxymethyl cellulose cross-linked with poly(acrylic acid-co-acrylamide). Some physico-chemical properties of the nanosorbents were characterized by various testing methods. The nanosorbent could be easily separated from aqueous solutions by an external magnetic field and the mass fraction of outer hydrogel shell was 20.3 wt%. The adsorption performance was investigated as the effects of solution pH, adsorbent content, initial dye concentration, and contact time. The maximum adsorption capacity was obtained at neutral pH of 7 with a sorbent dose of 1.5 g L−1. The experimental data of MB adsorption were fit to Langmuir isotherm model and Pseudo-second-order kinetic model with maximum adsorption of 34.3 mg g−1. XPS technique was applied to study the mechanism of adsorption, electrostatic attraction and physically adsorption may control the adsorption behavior of the composite nanosorbents. In addition, a good reusability of 83.5% MB recovering with adsorption capacity decreasing by 16.5% over five cycles of sorption/desorption was observed.
Despite their high porosity and wide applicability, silica xerogels face mechanical strength limitations for high-performance applications. This study presents an ambient-pressure sol-gel strategy utilizing calcium-glycerol synergy to produce robust xerogels with enhanced properties. Physicochemical analyses reveal that controlled Ca2+ incorporation (optimal at 6 wt.%) accelerates gelation kinetics while establishing a hybrid network through ionic complexation and hydrogen bonding. The resulting xerogels achieve exceptional compressive strength (30.8 MPa) while maintaining uniform mesoporosity (50–90 nm pore size). Remarkably, the as-prepared silica xerogels demonstrate outstanding thermal insulation, maintaining a 220 °C temperature differential in 300 °C environments. These results prove that the ambient-pressure sol-gel strategy utilizing calcium-glycerol synergy can enhance the mechanical performance and thermal insulation performance of silica xerogels with the dual actions of Ca2+-induced network reinforcement via silanol coordination and glycerol-mediated stress relief during ambient drying. Overall, this work can offer a scalable, energy-efficient approach to produce high-performance silica xerogels with huge potential in building envelopes and aerospace systems.
The interfacial incompatibility and insufficient mechanical performance of polylactic acid (PLA)/cellulose composites have severely restricted their practical applications. To address the critical issue of interfacial incompatibility in PLA/cellulose composites, this work developed a novel strategy employing rosin emulsion for blending modification of microcrystalline cellulose (MCC), followed by a one-step extrusion process to fabricate PLA composites. The corresponding analyses confirmed that the rosin has been successfully added to MCC surfaces, forming the hydrophobic interface while maintaining the cellulose I crystalline structure. Subsequently, rosin emulsion-modified MCC (MCC-R) reinforced PLA (PLA/MCC-R) composites were fabricated via twin-screw extrusion at varying MCC-R contents. The testing results illustrated that the introduction of 8 wt% MCC-R can enhance the mechanical properties of PLA/MCC-R composites with the flexural strength (125.5 MPa), tensile strength (30.8 MPa), Young’s modulus (1.19 GPa), and elongation at break (3.07%), which was attributed to enhanced filler dispersion and interfacial stress transfer. Overall, this work established a facile and sustainable strategy for developing multifunctional PLA composites with engineered interfaces and mechanical robustness, which is vital for practical application. The as-prepared PLA composites show promising application prospects in environmentally friendly packaging, biodegradable disposable products, and lightweight structural components.