Nowadays, despite significant advances in the field of biomaterials for tissue engineering applications, novel bone substituents still need refinement so they can be successfully implemented into the medical treatment of bone fractures. Generally, a scaffold made of synthetic polymer blended with nanofillers was proven to be a very promising biomaterial for tissue engineering, however the choice of components for the said scaffold remains questionable. The objects of the presented study were novel composites consisting of poly(ε-caprolactone) (PCL) and two types of graphene materials: graphene oxide (GO) and partially reduced graphene oxide (rGO). The technique of choice, that was used to characterize the obtained composites, was Raman micro-spectroscopy. It revealed that the composite PCL/GO differs substantially from the PCL/rGO composite. The incorporation of the GO particles into the polymer influenced the structure organisation of the polymeric matrix more significantly than rGO. The crystallinity parameters confirmed that the level of crystallinity is generally higher in the PCL/GO membrane in comparison to PCL/rGO (and even in raw PCL) that leads to the conclusion that the GO acts as a nucleation agent enhancing the crystallization of PCL. Interestingly, the characteristics of the studied nanofillers, for example: the level of the organisation (D/G ratio) and the in-plane size of the nano-crystallites (L_a) almost do not differ. However, they have an ability to influence polymeric matrix differently.

This paper presents the acetone sensing characteristics of Si-doped (1 at.%) tungsten oxide thin films prepared by glancing angle dc magnetron sputtering. The performance of Si-doped WO ₃ sensors in the concentration range of 0.04-3.8 ppm at operating temperatures of 150 °C-425 °C has been investigated. Doping of the tungsten oxide film with Si significantly decreases the limit of detection of acetone compared with the pure WO ₃ sensors reported in the literature. The gas sensor's response (S) to acetone was defined as the resistance ratio S = R _air /R _gas , where R _air and R _gas are the electrical resistances for the sensor in air and in gas, respectively. The maximum response measured in this experiment was S = 40.5. Such response was measured in the presence of 3.8 ppm of acetone at an operating temperature of 425 °C using a Si-doped (1 at.%) WO ₃ thin film deposited at 300 °C and annealed at 300 °C for 4 h in air. The films phase composition, microstructure, and surface topography have been assessed by X-ray diffraction, scanning electron microscope, atomic force microscope, and energy dispersive X-ray spectroscopy methods.

There is currently a growing demand for more effective thermal insulation materials with the best performance properties. This research paper presents the investigation results on the influence of two types of filler on the structure and properties of rigid polyurethane foam composites. Fly ash as a product of coal combustion in power plants and microspheres of 5, 10, 15, and 20 wt.%, were used as rigid polyurethane foams modifiers. The results of thermal analysis, mechanical properties testing, and cellular structure investigation performed for polyurethane composites show that the addition of fly ash, up to 10 wt.%, significantly improved the majority of the tested parameters. The use of up to 20 wt.% of microspheres improves the mechanical and thermal properties and thermal stability of rigid polyurethane foams.