Heat treatment of polymeric PBAT/PCL membranes containing activated carbon from Brazil nutshell biomass obtained by electrospinning and applied in drug removal

Abstract This work aimed to perform a heat treatment on biodegradable polymeric membranes produced by the electrospinning technique to be used in the retention of residual drugs from water. For this, a blend with a concentration of 20 % (w/v) was produced, composed of 75 % Poly(butylene adipate-co-terephthalate) (PBAT) and 25 % poly (e-caprolactone) (PCL) (w/w), solvated in chloroform (CL) and N,N-dimethylformamide (DMF) in the proportion of 85/15 % (v/v), respectively. A portion of 10 % (w/w) activated carbon from Brazil nut shell biomass (CA-BCB) was incorporated in the polymeric solution, which was subjected to electrospinning to obtain the polymeric membranes. Thermal treatments were then carried out on the surface of the electrospun membranes. The membranes were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and membranes surface wettability by contact angle. The results of the micrograph images (SEM) showed that the incorporation of CA-BCB produced fibers with smaller diameters without changing the chemical structure of the polymers, which was confirmed by the FTIR analysis. With the addition of activated carbon, there was an increase in the thermal stability of the material, which was confirmed by TGA analysis. In the permeability tests carried out with distilled water (1290 kg h−1 m-2) and tetracycline hydrochloride solution (TCH), 1220 kg h−1 m-2 with 200 min of operation. A PBAT/PCL membrane retention capacity, with heat treatment and addition of CA-BCB, of approximately 67 % was verified. This result suggests that the membranes produced by electrospinning, together with a heat treatment, can be used to retain emerging pollutants.