β-Glucosidase (BG) was immobilized by adsorption on wrinkled silica nanoparticles (WSNs) giving an active and stable biocatalyst for the hydrolysis of cellobiose. WSNs exhibiting both a central-radial pore structure and a hierarchical trimodal micro-/ mesoporous pore size distribution were synthesized. They were used as a matrix to immobilize BG, obtaining a biocatalyst (BG/WSNs) containing 150 mg of enzyme per gram of matrix. A complete textural and morphological characterization of BG/WSNs performed by the Brunauer−Emmett−Teller (BET) method, thermogravimetric (TG), Fourier transform infrared (FT-IR), and transmission electron microscopy (TEM) analyses showed that this matrix can generate a microenvironment particularly suitable for this enzyme. The immobilization procedure used allowed preserving most of the secondary structure of the enzyme and, consequently, its catalytic activity. The kinetic parameters of the cellobiose hydrolysis performed with the biocatalyst were determined and compared with those of the free enzyme. It was found that the apparent K M value of the biocatalyst was slightly lower than that of the free enzyme, indicating that the enzyme−substrate affinity was increased. A complete hydrolysis of cellobiose was observed for four consecutive runs, showing a high operational stability of the biocatalyst.

A building block approach, using a variety of benign solvent compositions and additives, offers a continuously developing strategy to render solvent-based electrospinning increasingly sustainable for the generation of polymer nanofibers.

Structural and functional properties of polymer composites based on carbon nanomaterials are so attractive that they have become a big challenge in chemical sensors investigation. In the present study, a thin nanofibrous layer, comprising two insulating polymers (polystyrene (PS) and polyhydroxibutyrate (PHB)), a known percentage of nanofillers of mesoporous graphitized carbon (MGC) and a free-base tetraphenylporphyrin, was deposited onto an Interdigitated Electrode (IDE) by electrospinning technology. The potentials of the working temperature to drive both the sensitivity and the selectivity of the chemical sensor were studied and described. The effects of the porphyrin combination with the composite graphene–polymer system appeared evident when nanofibrous layers, with and without porphyrin, were compared for their morphology and electrical and sensing parameters. Porphyrin fibers appeared smoother and thinner and were more resistive at lower temperature, but became much more conductive when temperature increased to 60–70 °C. Both adsorption and diffusion of chemicals seemed ruled by porphyrin according its combination inside the composite fiber, since the response rates dramatically increased (toluene and acetic acid). Finally, the opposite effect of the working temperature on the sensitivity of the porphyrin-doped fibers (i.e., increasing) and the porphyrin-free fibers (i.e., decreasing) seemed further confirmation of the key role of such a macromolecule in the VOC (volatile organic compound) adsorption.

Light polymeric soundproofing materials (density = 63 kg/m 3 ) of interest for the transportation industry were fabricated through electrospinning. Blankets of electrospun polyvinylpyrrolidone (average fiber diameter = (1.6 ± 0.5) or (2.8 ± 0.5) µm) were obtained by stacking disks of electrospun mats. The sound absorption coefficients were measured using the impedance tube instrument based on ASTM E1050 and ISO 10534-2. For a given set of disks (from a minimum of 6) the sound absorption coefficient changed with the frequency (in the range 200-1600 Hz) following a bell shape curve with a maximum (where the coefficient is greater than 0.9) that shifts to lower frequencies at higher piled disks number and greater fiber diameter. This work showed that electrospinning produced sound absorbers with reduced thickness (2-3 cm) and excellent sound-absorption properties in the low and medium frequency range.