Equilibration in a geranyl acetate emulsion

When passion meets purpose: love for chemistry drives female Jordanian professor

What summons this writing today is shedding light on my lifetime merits (Dr. Abeer Al-Bawab) leading up to becoming the first Jordanian woman to receive the IUPAC award. “I would like to say that I am the first Arab, but an Egyptian Academic Prof woman beat me to it”. As an organization that has existed for 102 years and which oversees the discoveries of many chemical stories and research, including that of the Periodic Table and Avogadro numbers, IUPAC and its nominations are certainly not to be taken lightly. It is my honor to receive this award and be selected among a prestigious group of scientists to have received this award. It is my hope that this writing inspires other aspiring chemists and scientists. Finally, it is my hope that my story exemplifies that when you are equipped with a strong passion for science, no adversity can stand in the way of your success.

On the Negative Surface Tension of Solutions and on Spontaneous Emulsification

The condition of negative surface tension of a binary regular solution is discussed in this paper using the recently reconfirmed Butler equation (Langmuir 2015, 31, 5796-5804). It is shown that the surface tension becomes negative only for solutions with strong repulsion between the components. This repulsion for negative surface tension should be so strong that this phenomenon appears only within a miscibility gap, that is, in a two-phase region of macroscopic liquid solutions. Thus, for a macroscopic solution, the negative surface tension is possible only in a nonequilibrium state. However, for a nano-solution, negative surface tension is also possible in equilibrium state. It is also shown that nano- and microemulsions can be thermodynamically stable against both coalescence and phase separation. Further, the thermodynamic theory of emulsion stability is developed for a three-component (A-B-C) system with A-rich droplets dispersed in a C-rich matrix, separated by the segregated B-rich layer (the solubility of B is limited in both A and C while the mutual solubility of A and C is neglected). It is shown that when a critical droplet size is achieved by forced emulsification, it is replaced by spontaneous emulsification and the droplet size is reduced further to its equilibrium value. The existence of maximum temperature of emulsion stability is shown. Using low-energy emulsification below this maximum temperature, spontaneous emulsification can appear, which is enhanced with further decrease of temperature. This finding can be applied to interpret the experimental observations on spontaneous emulsification or for the design of stable micro- and nanoemulsions.