Thermally flexible epoxy/cellulose blends mediated by an ionic liquid

Blends between the widely used thermoset resin, epoxy, and the most abundant organic material, natural cellulose are demonstrated for the first time. The blending modification induced by charge transfer complexes using a room temperature ionic liquid, leads to the formation of thermally flexible thermoset materials. The blend materials containing low concentrations of cellulose were optically transparent which indicates the miscibility at these compositions. We observed the existence of intermolecular hydrogen bonding between epoxy and cellulose in the presence of the ionic liquid, leading to partial miscibility between these two polymers. The addition of cellulose improves the tensile mechanical properties of epoxy. This study reveals the use of ionic liquids as a compatible processing medium to prepare epoxy thermosets modified with natural polymers.

Legal systemology and the geopolitics of Roman law: a response to Stuart Elden’s critique of Carl Schmitt’s spatial ontology

This paper explores the production, destruction, and reproduction of the geopolitical spaces of Roman law in order to offer an analysis of Schmitt’s (selective) notion of Jus Publicum Europaeum and its relevance to the current “depoliticization” and “dejuridification” of the world. By adopting a historical and geopolitical approach that reaches the boundaries of legal systemology and political theology, the present contribution investigates the manipulative and instrumentalist use of the material object of Rome’s (universalist) competence, namely the “territory” as dominium of its political intervention, which was ultimately (and idealistically) aimed at avoiding the natural destiny of any living being: birth, maturity, and death. Attention is therefore paid to the Roman strategy of (ontological?) contamination of its mythical identity through the legal and sociopolitical administration and regulation of its geographical spaces in terms of (non-)cultural signification. Through the analysis of such concepts as “nomos,” “Großraum,” “Ortung,” and “Ordnung,” it is claimed that Schmitt voluntarily chose to identify the Jus Publicum Europaeum with the geopolitical order produced during the Age of Discovery and not with the “comprehensive” Roman spatial order. The reason for this choice may be identified in the distortive use of Rome’s social relations and political allegiances that lay at the core of its genealogical expansionism (and subsequent inevitable dissolution) since the conquest of Veius in 396 BC and the historical compromise between patrician nobility and plebeians in 367 BC.

Rapid and effective cuticle removal from wool fibers using ionic liquid

Wool fibers are composed of cuticle and cortex cells, which are of obvious differences in many properties. The development of methods to isolate the two kinds of cells can provide platform to elucidate the roles they play in the characteristics of wool fibers. Here we demonstrate the cuticle can be completely and rapidly removed from the wool fibers by the use of ionic liquids, with inner cortex intact. Confocal microscope, SEM and FTIR have been applied to study the wool fibers after cuticle removal. In contrast to the traditional/long physical or chemical separation routes (>14 h), our method is very rapid (<1 h). This work demonstrates the ability of ionic liquid as a novel, rapid and efficient media for cuticle/ cortex isolation.

A highly conductive porous graphene electrode prepared via in situ reduction of graphene oxide using Cu nanoparticles for the fabrication of high performance supercapacitors

Herein, a new graphene/Cu nanoparticle composite was prepared via the in situ reduction of GO in the presence of Cu nanoparticles which was then utilized as a sacrificing template for the formation of flexible and porous graphene capacitor electrodes by the dissolution of the intercalated Cu nanoparticle in a mixed solution of FeCl3 and HCl. The porous RGO electrode was characterized by atomic force microscopy (AFM), Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). The as-prepared graphene/Cu nanoparticle composite and the pure graphene film after removal of Cu nanoparticles possessed high conductivity of 3.1 × 10³ S m^-1 and 436 S m^-1 respectively. The porous RGO can be used as the electrode for the fabrication of supercapacitors with high gravimetric specific capacitances up to 146 F g^-1, good rate capability and satisfactory electrochemical stability. This environmentally friendly and efficient approach to fabricating porous graphene nanostructures could have enormous potential applications in the field of energy storage and nanotechnology.

The restoration of the passivity of stainless steel Weldments in pickling solutions observed using electrochemical and surface analytical methods

In this study, a solution containing ammonium fluoride (NH4F) and nitric acid (HNO3) was used as an alternative to the conventional highly toxic pickling solution HF/HNO3 for pickling weldments of selected stainless steels including Type 316 stainless steel (UNS S31600), duplex stainless steel 2205 (UNS S32205), and super duplex stainless steel 2507 (UNS S32750). Electrochemical and surface analytical methods were used to understand the effects of pickling on the stainless steel weldments. Cyclic potentiodynamic polarization (CPP) test results indicated that the restoration of passivity of stainless steel weldments could be achieved by pickling the weldments in both HF/HNO3 solution and NH4F/HNO3 solutions. Scanning electron microscopy observation of the UNS S32750 weldment surface revealed that both the HF/HNO3 solution and the NH4F/HNO3 solution could remove the heat tint on the weldment. X-ray photoelectron spectroscopy analysis indicated that treatment in these two pickling solutions produced passive films with similar characteristics. Thus, this work suggests that the NH4F/HNO3 solution is a promising alternative to HF/HNO3 solution for the pickling of stainless steel weldments, and that the CPP test approach can be used in conjunction with surface analytical methods for further development of safer and environmentally friendly picklingsolutions.

Is being childless detrimental to a woman's health and well-being across her life course?

BACKGROUND: Childlessness is a growing phenomenon. Previous research examining health and well-being differentials between women with and without children has produced conflicting results. Most of this research has been conducted in the United States or parts of Europe. There has been limited research in Australia that has examined the health and well-being of women with and without children across the life course. The aim of the current study was to examine the association between motherhood status and general physical and mental health and well-being over a 10-year time period. METHODS: Using 10 waves of data from the Household, Income and Labour Dynamics in Australia study, longitudinal linear mixed models with time varying variables (both dependent and independent) were constructed to assess the effect of childlessness on health and well-being based on the Short Form-36 Health Survey Version 1 (n=52,381 observations). FINDINGS: Findings suggest that childless women experience poorer physical and mental health and well-being during the peak reproductive years; however, this trend is reversed for women aged 65 years or more. Although never-married, childless women experienced better health and well-being compared with mothers, this was not the case for childless women who were divorced, separated, or widowed or in a relationship. CONCLUSION: The findings support the notion that whether or not a woman has children does have consequences for her health and well-being; however, this differs across the life course.

Complex coacervation between flaxseed protein isolate and flaxseed gum

Flaxseed protein isolate (FPI) and flaxseed gum (FG) were extracted, and the electrostatic complexation between these two biopolymers was studied as a function of pH and FPI-to-FG ratio using turbidimetric and electrophoretic mobility (zeta potential) tests. The zeta potential values of FPI, FG, and their mixtures at the FPI-to-FG ratios of 1:1, 3:1, 5:1, 10:1, 15:1 were measured over a pH range 8.0-1.5. The alteration of the secondary structure of FPI as a function of pH was studied using circular dichroism. The proportion of a-helical structure decreased, whereas both β-sheet structure and random coil structure increased with the lowering of pH from 8.0 to 3.0. The acidic pH affected the secondary structure of FPI and the unfolding of helix conformation facilitated the complexation of FPI with FG. The optimum FPI-to-FG ratio for complex coacervation was found to be 3:1. The critical pH values associated with the formation of soluble (pHc) and insoluble (pHΦ1) complexes at the optimum FPI-to-FG ratio were found to be 6.0 and 4.5, respectively. The optimum pH (pHopt) for the optimum complex coacervation was 3.1. The instability and dissolution of FPI-FG complex coacervates started (pHΦ2) at pH2.1. These findings contribute to the development of FPI-FG complex coacervates as delivery vehicles for unstable albeit valuable nutrients such as omega-3 fatty acids.