This review aims to report the status of the research on polyaryletherketone-based thermoplastic blends (PAEK). PAEK are high-performance copolymers able to replace metals in many applications including those related to the environmental and energy transition. PAEK lead to the extension of high-performance multifunctional materials to target embedded electronics, robotics, aerospace, medical devices and prostheses. Blending PAEK with other thermostable thermoplastic polymers is a viable option to obtain materials with new affordable properties. First, this study investigates the miscibility of each couple. Due to different types of interactions, PAEK-based thermoplastic blends go from fully miscible (with some polyetherimides) to immiscible (with polytetrafluoroethylene). Depending on the ether-to-ketone ratio of PAEK as well as the nature of the second component, a large range of crystalline structures and blend morphologies are reported. The PAEK-based thermoplastic blends are elaborated by melt-mixing or solution blending. Then, the effect of the composition and blending preparation on the mechanical properties are investigated. PAEK-based thermoplastic blends give rise to the possibility of tuning their properties to design novel materials. However, we demonstrate hereby that significant research effort is needed to overcome the lack of knowledge on the structure/morphology/property relationships for those types of high-performance thermoplastic blends.

Viscous fluid exiting a long horizontal circular pipe develops a complex structure comprising a primary jet above and a smaller secondary jet below with a thin fluid curtain connecting them. We present here a combined experimental, theoretical, and numerical study of this “Torricelli's curtain” phenomenon, focusing on the factors that control its morphology. The dimensional parameters that define the problem are the pipe radius a; the mean exit velocity U of the fluid; the gravitational acceleration g; and the fluid's density ρ, kinematic viscosity ν, and coefficient of surface tension γ. Rescaling of experimentally measured trajectories of the primary and secondary jets using a for the vertical coordinate and $L_D=U{(a/g)}^{1/2}$ for the horizontal coordinate x collapses the data onto universal curves for $x<10L_D$ . We propose a theoretical model for the curtain in which particle trajectories result from the composition of two motions: a horizontal component corresponding to the evolving axial velocity profile of an axisymmetric viscous jet and a vertical component due to free fall under gravity. The model predicts well the trajectory of the primary jet, but somewhat less well that of the secondary jet. We suggest that the remaining discrepancy may be explained by surface tension-driven (Taylor–Culick) retraction of the secondary jet. Finally, direct numerical simulation reveals recirculating “Dean” vortices in vertical sections of the primary jet, placing Torricelli's curtain firmly within the context of flow in curved pipes.

Testing the reliability of bonded joints in material assemblies is one of the major subjects in the aeronautical industry. One of the methods for characterizing adhesion is based on the study of the roughness of the fracture surfaces of assemblies. In this study, the interest is focused on the quantification of the adhesion of the bonded structure by the corner cleavage test, allowing the study of crack propagation within bonded assemblies. Optical profilometry measurements, obtained by scanning the surface of the fractured surfaces of monoadhesives: ABT M52, copolymer-doped and non-nanostructured AHT are used. The aim of the profilometric study is to quantify surface roughness. To go further than traditional methods of characterizing roughness, we analyze the profiles using mathematical methods to confirm the experimental studies and extract more geometric information. We apply various techniques of topological data analysis (TDA) to extract the topological features of the profiles. These techniques recover experimental elements in a quantitative manner. Persistence diagrams give us a multi-scale characterization of the rupture facies, attesting the voids, micro-cracks at nano-level, quantifying the maximum amplitude of the peaks at micro level. We extract features vectors using persistent images for each profile and we look for similarities in persistence diagrams using Bottleneck and Wasserstein distances in perspective of a machine learning application in a future study. Then the profiles were studied by Takens embedding which will produce a point cloud analyzed by homological persistence in order to produce indications of periodicity or quasi-periodicity. This computational topological approach makes it possible to extract the essential characteristics of the surface and roughness of the profile of the adhesives in order to conclude on their toughness and fracture resistance.

We experimentally investigate the foamability of PVP 2.5k/ethanol and amorphous α-maltose/methanol solution under moderate vacuum. We investigate the influence of the solution concentration and the impact of the container shape on the foamability. We show that spontaneous foaming is strongly influenced by the container’s shape. The concentration of the solution is another important parameter, and our results suggest that, for a given solution, there seems to be only a narrow concentration window that enables the formation of a stable foam. When loaded with a model hydrophobic drug (ibuprofen), the spontaneous foaming enhances the dispersion of the drug molecules, by acting as an additional mixing force through extensive shear of the solution.

A probe tack test, coupled with in situ imaging, was used to evaluate the influence of an air plasma treatment on glass substrates on the fracture energy of nanostructured epoxy-amine resins. Nanostructuration was achieved by the addition of thermoplastic triblock copolymers. The influence of the surface treatment was assessed by splitting the fracture energy (tack energy) into three main contributions (cavitation, viscous flow, and stretch). We showed that before gelation, the interfacial strength depended on the nature of the copolymers and on their interaction with grafted functions (R-COOH and R-C=O) by air plasma treatment. The latter also influenced the cohesion of the resins, impacting the copolymers' phase separation and, as a consequence, conversion rate. The tack test, coupled with rheology and thermal (differential scanning calorimetry) measurements, was relevant to explain how the balance of interactions contributed to the fracture energy up to the gel point.