We report the nanostructures in a novel microemulsion system of silicone oil, water and a surfactant mixture of an anionic and a nonionic surfactant. The phase diagram of the investigated system exhibits two isotropic single-phase channels for constant temperature. The upper channel, that is the channel with the higher mass fraction of nonionic surfactant, starts with an L 3 -phase at the water side, and passes through a minimum continuously to the oil side. The channel with the lower mass fraction of nonionic surfactant starts with an L 1 -phase at the water side, and passes with increasing oil content and increasing mass fraction of nonionic surfactant to the middle of the phase diagram and ends there. No connection between the two channels was detected at a surfactant concentration of 15%. The two channels are separated by a single L a -phase and multiphase regions. In contrast to the results from microemulsions with nonionic surfactants, cryo-TEM micrographs on this system show that the upper phase channel has a bicontinuous structure from zero to only about 35% of oil. At higher oil content the channel contains water droplets in a continuous oil phase. At a water/oil ratio of 1 : 1, the structure looks like a polyhedral foam structure or a high internal phase emulsion (HIPE) structure, and not like the usual bicontinuous structure, as generally assumed. Nevertheless, the dimensions of the imaged bicontinuous and water-in-oil-structures were consistent with the theoretical consideration for nanostructures in microemulsions. The lower channel with its o/w-structure could not well be imaged with the cryo-TEM method. Instead of small droplets, small vesicles were imaged, that obviously were formed by the loss of oil in the thin film during the specimen preparation process for cryo-TEM.

Microemulsion phases have been prepared for the first time from the silicone oil "M(2)" (hexamethyldisiloxane) and a surfactant mixture of a nonionic surfactant "IT 3" (isotridecyltriethyleneglycolether) and an ionic surfactant Ca(DS)(2) (calciumdodecylsulfate). For such a surfactant mixture the hydrophilicity of the system can be tuned by the mixing ratio of the two components. With increasing IT 3 content, the surfactant mixtures show a L(1)-phase, a wide L(α)-region and a narrow L(3) sponge phase. For constant temperature, two single phase channels exist in the microemulsion system. The lower channel (low IT 3 content) ends in the middle of the phase diagram with equal amounts of water and oil, the upper channel begins with the L(3)-phase and passes all the way to the oil phase. Conductivity data show that the upper channel has a bi-continuous morphology up to 40% oil while the lower channel consists of oil droplets in water. In contrast to previous studies on nonionic systems, the two single phase channels are not connected and microemulsions with equal amount of oil and water do not have a bicontinuous structure.

We report a phase diagram for a novel microemulsion that consists of oil and water and of 15% of a surfactant mixture of an anionic and a nonionic surfactant. The phase diagram shows an optically isotropic channel that passes from the water-rich side to the oil-rich side. In contrast to the isotropic channel in microemulsions of nonionic surfactants, the reported system undergoes an abrupt transition of the structure in the isotropic channel with increasing oil content. The structural transition is reflected in the conductivity and the viscosity of the channel. Between the L(3) phase and the sample with 6% of oil the conductivity decreases 3 orders of magnitude. Thus, the bicontinuous structure at the origin of the channel transforms already with 6% of oil to a w/o structure. The viscosity shows a strong maximum at the transition. The w/o structures with low oil content were successful directly imaged by cryo-TEM. It can be seen that water is contained inside a polyhedral foam-like structure, where the polyhedral film is formed of the oil and the surfactant. The dimensions of the polyhedra are in the range of 20-100 nm. We call this structure "high internal phase microemulsion" (HIPME).

Excessive online shopping cart abandonment rates constitute a major challenge for e-commerce companies and can inhibit their success within their competitive environment. Simultaneously, the emergence of the Internet’s commercial usage results in steadily growing volumes of data about consumers’ online behavior. Thus, data-driven methods are needed to extract valuable knowledge from such big data to automatically identify online shopping cart abandoners. Hence, this contribution analyzes clickstream data of a leading German online retailer comprising 821,048 observations to predict such abandoners by proposing different machine learning approaches. Thereby, we provide methodological insights to gather a comprehensive understanding of the practicability of classification methods in the context of online shopping cart abandonment prediction: our findings indicate that gradient boosting with regularization outperforms the remaining models yielding an F1-Score of 0.8569 and an AUC value of 0.8182. Nevertheless, as gradient boosting tends to be computationally infeasible, a decision tree or boosted logistic regression may be suitable alternatives, balancing the trade-off between model complexity and prediction accuracy.

We have studied the dynamic and rheological properties in the single-phase channels of a microemulsion system with a mixed anionic/nonionic surfactant system and decane from the aqueous to the oil phase. One isotropic channel, called the "upper" channel, begins at the L(3) phase (sponge-like phase) of the binary surfactant mixture on the water side and passes with a shallow minimum for the surfactant composition to the oil side. The other "lower" single-phase channel begins at the micellar L(1) phase and ends in the middle of the phase diagram. Both isotropic channels are separated by a huge anisotropic single phase L(α) channel that reaches from the water side to 90% of oil in the solvent mixture. The structural relaxation time of the viscous fluids could be measured with electric birefringence (EB) measurements, where a signal is caused by the deformation of the internal nanostructure of the fluids by an electric field. For the L(3) phase, the EB signal can be fitted with a single time constant. With increasing oil in the upper channel, the main structural relaxation time passes over a maximum and correlates with the viscosity. Obviously, this time constant controls the viscosity of the fluid (η(o) = G'·τ). It is remarkable that the longest structural relaxation time increases three decades, and the viscosity increases two decades when 10% of oil is solubilized into the L(3) phase. Conductivity data imply that the fluid in the upper channel has a bicontinuous structure from the L(3) phase to the microemulsion with only 10% oil. In this oil range, the conductivity decreases three decades, and the electric birefringence signals are complicated because of a superposition of up to three processes. For higher oil ratios, the structure obviously changes to a HIPE (high internal phase emulsion) structure with water droplets in the oil matrix.