9Biomass fractionation into its individual building blocks poses a major challenge

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Highlights Cellulose acetate films were impregnated with thymol using supercritical CO2  Target thymol contents for desired antibacterial activity were in the range 26-30%  Thymol prevented S. aureus and P. aeruginosa attachment to films' surfaces  Released thymol reduced biofilm formation on the surrounding surfaces  The films showed strong anti-biofilm activity against antibiotic resistant strains Graphical abstarct

The goal of this work was to synthesize and characterize ternary rubber blends based on polyisoprene (natural rubber (NR)), polybutadiene rubber (BR), and styrene–butadiene rubber (SBR) (NR/BR/SBR = 25/25/50) reinforced with different loading silica (SiO2) nanoparticles (0–100 part per hundred parts of rubber (phr)). The specimens were subjected to thermooxidative aging at 100°C, for two times: at 72 and 168 h, respectively, and then mechanically stretched to fracture by tension with a Zwick 1425 (Zwick GmbH, Ulm, Germany) universal tensile testing machine. Rheological and mechanical properties were used as characterization of the ternary rubber blends. The reinforcing performance of the filler was investigated using rheometric, mechanical, and swelling measurements, thermogravimetric analysis, scanning electron microscopy, and Fourier transform infrared spectroscopy with attenuated total reflectance. Hardness, tensile strength, elongation at break, and swelling degree were assessed before and after thermal aging. There was a remarkable decrease in the optimum cure time ( tc90) and the scorch time ( ts2), which was associated with a decrease in the cure rate index of (NR/BR/SBR = 25/25/50) ternary rubber blend with 60 phr of filler loading. Interaction between rubber blend and SiO2 nano-filler is confirmed by moving absorption band from 1450 cm−1 to 1480 cm−1.

Supercritical CO 2 was used as a green solvent and impregnation medium for loading cellulose acetate beads with carvacrol in order to obtain a biomaterial with antibacterial properties. Supercritical solvent impregnation was performed in a high-pressure view cell at temperature of 50 ∘ C and pressures of 10, 21, and 30 MPa with the processing time ranging from 2 to 18 h. The rate of impregnation increased with the pressure increase. However, maximum impregnation yield (round 60%) was not affected by the pressure applied. Selected samples of the impregnated cellulose acetate containing 6-60% of carvacrol were proven to have considerable antibacterial effect against Gram-positive and Gram-negative bacterial strains including methicillin-resistant Staphylococcus aureus which causes severe infections in humans and animals. In addition, cellulose acetate beads containing 6.0-33.6% of carvacrol were shown to have a porous structure with submicron pores which is of interest for the controlled delivery applications.

is the first study on supercritical impregnation of G/Ch films with clove oil (CO) • CO in films was affected by CO2 pressure, impregnation time and G:Ch ratio • CO loading was favoured at 10-20 MPa, impregnation time of 2-6 h and Gwt% 25-50% • ScCO 2 treatment had the highest plasticizing effect on G/Ch50:50 • Thermal stability of the G/Ch film with 56 mg CO/g film to 110 °C was demonstrated Abstract Supercritical CO 2 impregnation process was used for the first time to fabricate biodegradable gelatin-chitosan (G/Ch) films containing clove oil (CO) for potential use in active food packaging. All the impregnations were carried out at moderately low temperature (40 °C). Aiming to maximize CO loading in the films with acceptable morphological, structural and thermal properties, CO 2 pressure, impregnation time and G:Ch mass ratio were varied. Gelatin fraction in the films of 25-50 wt.%, scCO 2 pressures of 10-20 MPa and impregnation time of 2-6 h impregnation favoured the CO loading. Processing of the film with equal gelatin to chitosan mass ratio (G/Ch 50:50) at 10 MPa for 2 h yielded sufficiently high loading (56 mg CO/g film) without an adverse effect on morphological properties. The G/Ch 50:50 film was therefore chosen for structural and thermal analyses. ATR-FTIR analysis confirmed successful CO incorporation into the G/Ch 50:50 and its interaction with the film. Plasticizing effect of scCO 2 and CO on the film was evidenced by DSC. Incorporation of 56 mg CO/g film into the G/Ch 50:50 didn't affect thermal stability of the film. Beside environmental benefits, supercritical impregnation process enables fast fabrication of G/Ch bio-composite films containing CO, thermally stable to 110 °C, which is suitable for most of food packaging applications.

The FASTSUGARS process for sugars' recovery from agricultural biomass was scaled 14 up from laboratory to pilot plant scale. System performance was evaluated by 15 comparing the results obtained from sugar beet pulp and wheat bran in laboratory and 16 pilot plants. Similar trends were found for each biomass in both plant: as reaction time 17increased, selectivity to sugars decreased and conversion and degradation rate increased. 18Then, to bring the FASTSUGARS process closer to industrial applications, the particle 19 size of the biomass was increased in the pilot plant. It was found that the particle size 20 acted as a mass transfer resistance, slowing down the hydrolysis of biomass, providing 21 lower conversion and therefore reducing sugars' degradation (degradation yield was 22 lower than 15 % in the pilot plant). In that way, higher selectivity to sugars was 23

Purpose: Poly(methyl methacrylate) (PMMA) is the most commonly used material in the production of dental prostheses, and its application is often accompanied by the formation of biofilm. The aim of this work was the preparation of a PMMA/gold nanoparticles (AuNps) composite to improve the antimicrobial properties of heat-polymerised PMMA. The AuNPs were synthesised from gold (III) acetate by Ultrasonic Spray Pyrolysis (USP). In the present study, flexural strength and elastic modulus were investigated, as well as thermal conductivity, density and hardness of the PMMA/ AuNps` nanocomposite, with different concentrations of AuNps. Flexural strength and elastic modulus were measured using a three-point bending test, and surface hardness was evaluated using the Vickers hardness test. The thermal conductivity of the samples was measured using the Transient Plane Source (TPS) technique. Density was determined by the pycnometry procedure. Statistical analysis was conducted on the data obtained from the experiments. Results: The flexural strength and elastic modulus of AuNps/PMMA nanocomposites decreased for all groups containing AuNps. Thermal conductivity and density increased in all groups containing AuNps compared to the control group, but it was not significant in all groups. Vickers hardness values increased significantly with an increase in AuNps` content, with the highest value 21.45 HV obtained at 0.74 wt% of AuNps. Statistical analysis was performed by means of the SPSS 19 software package. Conclusions: Incorporation of AuNps into heat-polymerised PMMA resin led to decrease of the flexural strength and elastic modulus. At the same time, the density, thermal conductivity and hardness increased.