Fecha de publicación: -- Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE Composition-tunable lignocellulosic aerogels are produced from Eucalyptus spp. bark by combining cellulose, lignin, and microfibrillated cellulose without post-synthetic functionalization. The resulting porous architectures show contaminant-dependent performance: CEL favors cooking-oil uptake, CEL-M favors pump-oil uptake, and CEL-L-M provides the highest measured Cu2+ uptake. These findings establish composition as a direct design variable for multifunctional biomass-derived adsorbents.

ABSTRACT
Composition-tunable lignocellulosic aerogels were produced from Eucalyptus spp. bark as adsorbents without additional chemical functionalization. Four formulations comprising cellulose, lignin, and microfibrillated cellulose (MFC) were freeze-dried: cellulose (CEL), cellulose/MFC (CEL-M), lignin/MFC (L-M), and cellulose/lignin/MFC (CEL-L-M) aerogels. The samples were characterized by SEM, nitrogen physisorption, XRD, FTIR, density, and porosity. All aerogels exhibited ultralow density and porosity above 99%, with composition-dependent fibrillar organization, crystallinity, and pore architecture. Bru nauer–Emmett–Teller (BET) surface areas ranged from 0.95 to 7.37 m2 g−1 for as-synthesized samples and reached 18.38 m2 g−1 after Cu2+ adsorption. CEL showed the highest used cooking-oil uptake (approximately 40 g g−1), whereas CEL-M performed best for used pump oil (38.81 g g−1). Cu2+ adsorption increased from pH 2 to pH 4–5; CEL-L-M reached the highest capacity (1.1337 g g−1) at pH 5 after 30 min, while L-M reached 0.8964 g g−1 within 15 min and remained above 1.06 g g−1 from 30 to 60 min. FTIR changes and Cu detection by EDS supported pH-regulated binding at oxygen-containing sites. Accordingly, cellulose, lignin, and MFC contributed differently: CEL maximized cooking-oil uptake, CEL-M maximized pump-oil uptake, while L-M and CEL-L-M provided the fastest Cu2+ uptake and highest capacity, respectively.