The stability of a variety of lyotropic liquid crystals formed by a number of polyoxyethylene nonionic surfactants in the room-temperature ionic liquid ethylammonium nitrate (EAN) is surveyed and reported. The pattern of self-assembly behaviour and mesophase formation is strikingly similar to that observed in water, even including the existence of a lower consolute boundary or cloud point. The only quantitative difference from water is that longer alkyl chains are necessary to drive the formation of liquid crystalline mesophases in EAN, suggesting that a rich pattern of "solvophobic" self-assembly should exist in this solvent.

The structure of micelles formed by nonionic polyoxyethylene alkyl ether nonionic surfactants, C n E m , in the room-temperature ionic liquid, ethylammonium nitrate (EAN), has been determined by small-angle neutron scattering (SANS) as a function of alkyl and ethoxy chain length, concentration, and temperature. Micelles are found to form for all alkyl chains from dodecyl through to octadecyl. Dodecyl-chained surfactants have high critical micelle concentrations, around 1 wt%, and form weakly structured micelles. Surfactants with longer alkyl chains readily form micelles in EAN. The observed micelle structure changes systematically with alkyl and ethoxy chain length, in parallel with observations in aqueous solutions. Decreasing ethoxy chain length at constant alkyl chain length leads to a sphere to rod transition. These micelles also grow into rods with increasing temperature as their cloud point is approached in EAN.

Post-blast nitrogen oxide fumes (NOx) from coal overburden blasting may occur in a variety of geological conditions with the use of bulk ammonium nitrate (AN) based explosive products. In Australia, government directives to stop blasting activities because of NOx fume incidences have led to costly delays in production, which has directly impacted on the ability of operations to meet production targets. Nitrogen oxide and nitrogen dioxide can cause serious health risks to persons exposed, with excessive levels of NO 2 also affecting the viability of flora and root systems. A number of research projects in Australia have focussed on minimising the risk of NOx fumes by better understanding the behaviour of current explosive products. The main outcomes from these projects have been the development and implementation of guidelines or administrative controls to minimise the NOx fume risk and reduce the potential exposure to the hazard. This paper describes preliminary work to provide a step-change solution that has the potential to completely eliminate the NOx hazard. A novel formulation that substitutes the use of AN with oxygenated water (OW) as the main oxidising agent has been developed and recently patented as part of a PhD program at The University of Queensland. The detonation properties of mixtures made with OW and fuel were studied. Unconfined velocities of detonation (VODs) tests of OW sensitised mixtures were conducted. It was found that for reliable detonation to occur, a minimum level of sensitisation must be accomplished. Adequately sensitised mixtures, with a water content of 47% by weight, were able to detonate at velocities in the range of 2600-5000 m s 21 , with a critical diameter of the order of 23 mm. The recorded detonation velocities were clearly dependent on the mixture density and charge diameter, similar to the non-ideal behaviour of AN-based commercial explosives.

Mining explosives based on ammonium nitrate(V) are safe and effective, however, the risk of NOx fume production during blasting is still present. In 2013, a project to eliminate NOx fumes from blasting began and hydrogen peroxide was chosen to replace ammonium nitrate(V) as the oxidiser. Previous work in this area demonstrated that hydrogen peroxide/fuel-based mixtures were able to detonate, provided that they are initiated under a situation of high confinement and also using hydrogen peroxide at relatively high concentrations. In contrast, a comprehensive study was conducted to determine the detonation properties of hydrogen peroxide/fuel-based mixtures that used hydrogen peroxide at lower concentrations (below 50 wt.%), detonated in unconfined conditions and used void sensitisation to achieve an efficient detonation reaction. This article presents the results of the influence of the density, water content, critical diameter and type of void sensitisation on the velocity of detonation (VOD) of hydrogen peroxide/ fuel-based explosive mixtures. The results indicate that the mixtures can achieve a different VOD which depends on the size of the sensitising voids and more importantly, the mixtures behave as non-ideal explosive, similarly to ammonium nitrate-based explosives, but with the advantage of being a NOx-free explosive.

This paper reports the results of a preliminary monitoring program designed to quantify the in situ performance of newly developed hydrogen peroxide based explosives. Their advantage is that they do not produce NOx fumes upon detonation. Direct measurements of velocity of detonation, pressure, temperature and displacement were obtained. Detonation velocities ranged from 2607 to 5100 m s −1 with differences mainly attributed to density variations. The data showed consistent relative differences in pressure and temperature with measurements in the range of 0.6-2.6 GPa and 2036-3551 °C respectively. Multiple hole tests showed that there was no adverse impact on product behaviour such as dead pressing or desensitisation. Video analysis confirmed that displacement was prominent in single hole crater tests but limited in multiple hole tests. Observations confirmed that new fracturing and dilation of discontinuities was evident; with relative differences in fragmentation associated with changes in rock mass conditions.