Tunable Properties of Non‐Volatile Magnetic Mixtures on Different Surfaces

In this work, the surface nature-dependent behaviors of magnetic deep eutectic solvents (MDESs) and magnetic low-transition-temperature non-volatile mixtures (MLTTMs) are reported for the first time. It has been observed that the surface of the material where the MDES or the MLTTM is placed could considerably affect the dispersion and the magnetic and structural properties of these magnetic mixtures. Different techniques and analyses have been carried out to highlight the differences observed in the properties depending on the material on which these magnetic mixtures are placed. To that end, differential scanning calorimetry (DSC), surface tension, contact angle and scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) measurements have been performed. As a result, it has been shown that the MDESs or MLTTMs are retained and adhered to glass surfaces, resulting in a loss of magnetism of the mixture in addition to a loss in the performance of synthesis carried out on the closeness of glass materials as the interaction between the glass and the mixture modify the composition and therefore the properties. As a preliminary result, when using these magnetic mixtures as extractant solvents in dispersive liquid-liquid microextraction, the MDES or MLTTM is retained on the walls of the glass tubes reducing the extraction efficiency, repeatability and the extraction recovery using an external magnetic field. For all these reasons, polypropylene materials should be recommended when handling magnetic deep eutectic solvents and non-volatile MLTTMs.