Superoleophobicity is a phenomenon where the contact angles of various oil droplets with low surface tension on a solid surface are larger than 150°. In the past few years, there has been much growing interest in the design and application of superoleophobic surfaces. Such surfaces have great significance for both fundamental research and a variety of practical applications, including oil-repellent coatings, self-cleaning, oil/water separation, oil droplet manipulation, chemical shielding, anti-blocking, designing liquid microlens, oil capture, bioadhesion, guiding oil movement and floating on oil. Herein, we systematically summarize the recent developments of superoleophobic surfaces. This review focuses on the design, fabrication, characteristics, functions, and important applications of various superoleophobic surfaces. Although many significant advances have been achieved, superoleophobic surfaces are still in their "toddler stage" of development. The current challenges and future prospects of this fast-growing field of superoleophobicity are discussed.

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Radiofrequency (RF) field wave behavior and associated nonuniform image intensity at high magnetic field strengths are examined experimentally and numerically. The RF field produced by a 10-cm-diameter surface coil at 300 MHz is evaluated in a 16-cm-diameter spherical phantom with variable salinity, and in the human head. Temporal progression of the RF field indicates that the standing wave and associated dielectric resonance occurring in a pure water phantom near 300 MHz is greatly dampened in the human head due to the strong decay of the electromagnetic wave. The characteristic image intensity distribution in the human head is the result of spatial phase distribution and amplitude modulation by the interference of the RF traveling waves determined by a given sample-coil configuration. Enhancements in signal-to-noise ratio (SNR) and T* 2 contrast arising from high static magnetic field strengths are desirable for in vivo MR applications. Thus, the number of high-field human MRI systems has increased rapidly in recent years (1-10). The advent of high-field human imaging systems introduces new challenges in radiofrequency (RF) engineering (11,12). Because at high frequencies the wavelength of the RF field is comparable to or less than that of the dimension of the human body, the RF magnetic field (B 1 ) inside a sample exhibits prominent wave behavior (13-16). Additionally, the homogeneity of the B 1 field and source currents in the RF coil are strongly perturbed by sample loading (17-19). The B 1 field distribution inside a sample is important for both specific absorption rate (SAR) assessment and RF coil engineering at high frequency. However, mathematical treatment of the RF field in such systems can be extremely complicated because 1) the quasi-static approximations are no longer valid, and Maxwell's wave equation must be employed; and 2) the geometry of the human body is irregular, and electromagnetic properties of tissues are heterogeneous. Thus, computer numerical calculation becomes an effective and indispensable tool for studying interactions of the RF field with the human body at high field (20 -24). Associated with the RF field wave behavior, the distributions of the B 1 field and its circularly polarized components B ϩ and B -, which are directly responsible for the MR image intensity distribution, become distinctively different from one another. Consequently, the relationship of RF field polarization to coil configuration and sample electric properties needs to be analyzed in order to understand the resultant image intensity distribution. Computer modeling provides an effective way to study this problem, and may provide insight into complex RF field wave behavior and its dependence on the electrical properties of the sample. In this report, we present a study specifically devised to analyze high-frequency wave behavior of the RF field with the aid of numerical calculation and parallel experimental measurements. METHODSThe study was carried out using water and saline phantoms with a 10-cm-diameter sur...