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Limited attention has been paid to repellency and wettability‐confined transport of low‐surface‐tension liquids, such as oils, alcohols, and hydrocarbons. This is because repellency becomes very difficult for fluids with surface tension below 30 mN m−1. This situation is encountered in many engineering applications using organic liquids and thus, oleophobic surfaces are of high technological importance. In this work, a nanocomposite coating comprising of fluorinated silica micro‐ and nanoparticles (filler), a copolymer (binder), and traces of fluorinated polyhedral oligomeric silsesquioxane (additive, lowest surface‐energy crystalline material reported to date) is spray‐deposited on a surface pretextured by laser etching, a technique that requires no lithographic processing. The approach results in surfaces that can repel liquid hydrocarbons with surface tension as low as 21.14 mN m−1 and also hinder the spreading of heptane (19.74 mN m−1) at room temperature. The repellency of several organic liquids with surface tensions in the range of 19.7 – 27 mN m−1 is experimentally investigated and compared with water (baseline case). To study the effect of fluid properties, comparisons are performed between the distances traveled and the velocities of microliter droplets transported pumplessly on wedge‐shaped wettability‐patterned tracks that confine the liquids by the superoleophobic background surrounding the wettable tracks. [ABSTRACT FROM AUTHOR]

Directional liquid transport (DLT) on fibrous systems has been widely used in both natural organisms and practical applications as an important mass transfer strategy. So far, DLTs on fibers are heavily dependent on the conical structure that enables generating the Laplace pressure difference. For the cylindrical fibers, liquid can only transport evenly along both directions of the axis driven by the capillary forces between fibers, which however hardly proceeds directionally in a controllable way. Here, the authors revealed that the dual cylindrical hairs bear the ability of DLT, which is attributable to the wet‐rebuilt open‐wedged scales. Capillary forces along wedge corners facilitate the liquid transport in the against‐scale direction, while the pinning effect at the sharp edges of open‐wedges works cooperatively with the anisotropic retention force imparted by the ratchet structures to inhibit liquid spreading in the with‐scale direction. Consequently, liquid prefers to transport in the against‐scale direction on dual cylindrical hairs. Drawing inspirations, the authors develop the conceptual‐model of dual cylindrical fibers that is capable of DLT, and moreover the DLT with different rectification ratios can be well‐controlled depending on the opening angle of wedges. The result offers new insights for manipulating liquid using cylindrical fibrous systems. [ABSTRACT FROM AUTHOR]

• Terahertz pulsed imaging was used to investigate the liquid transport kinetics of α -alumina powder compacts. • A range of compaction forces and sintering conditions were used for the terahertz measurements. • The microstructure characteristics as well as the surface properties of the alumina compacts have an impact on the water ingress rate. • The mass transport mechanism of the water ingress into the alumina compacts is consistent with Darcy flow. • The hydraulic radius of the alumina compacts was determined. Investigating the liquid transport kinetics of solid catalysts is of great importance for gaining a better understanding of the manufacturing and performance of such catalysts during reaction upon contact with the liquid. Terahertz pulsed imaging (TPI) coupled with a newly designed flow cell was used to quantify the rate of water ingress into α -alumina pellets with a range of different porosities. A wide range of compaction forces (cold compaction, 7–58 kN) and sintering conditions (no firing and sintering at 1200 and 1300 °C) was investigated to explore the optimal pellet microstructure, i.e. mechanically strong but sufficiently porous for fast liquid transport kinetics. The results confirm that both the microstructure characteristics, particularly porosity, as well as the surface properties, i.e. wettability, influence the liquid transport kinetics. Fitting the TPI penetration rates with a power law shows that the type of observed mass transport characteristics is consistent with Darcy flow. The Lucas–Washburn equation was used to calculate the hydraulic radius based on the transport data. In summary, the results demonstrate that TPI has great potential to study the liquid transport kinetics of porous ceramic catalysts and catalyst supports and that can comfortably quantify transport processes at rates of 250 μm s−1 and beyond in such substrates for better quality control and optimised design and performance of such materials. [ABSTRACT FROM AUTHOR]

The ceramic materials' properties and the penetrating liquid both influence liquid transport into ceramic catalytic materials. Terahertz pulsed imaging (TPI) in combination with a flow cell was used to investigate the transport process of polar and less polar solvents into a range of α -alumina powder compacts. The TPI results show that the alumina samples with the largest heating rate (200 °C h−1) have the fastest water transport. The TPI results also reveal that 1-octanol takes much longer to transport through the alumina samples than water, as the viscosity of 1-octanol is much larger than that of water. Since 1-octanol is semi-transparent to terahertz radiation, it was possible to study the liquid transport process and the structural changes behind the liquid front, such as the change in the refractive index of the compact and the fill fraction of 1-octanol in the compact as a function of time. • The transport of solvents with different polarities into a range of α -alumina powder compacts was investigated using terahertz pulsed imaging. • The alumina samples with the largest heating rate of sintering (200 °C h−1) have the fastest water transport. • The properties of the solvent, e.g. viscosity, have an impact on its transport through the alumina samples. • Structural changes behind the liquid front were studied as 1-octanol is semi-transparent at terahertz frequencies. [ABSTRACT FROM AUTHOR]

The magnetic actuation of deposited drops has mainly relied on volume forces exerted on the liquid to be transported, which is poorly efficient with conventional diamagnetic liquids such as water and oil, unless magnetosensitive particles are added. Herein, we describe a new and additive-free way to magnetically control the motion of discrete liquid entities. Our strategy consists of using a paramagnetic liquid as a deformable substrate to direct, using a magnet, the motion of various floating liquid entities, ranging from naked drops to liquid marbles. A broad variety of liquids, including diamagnetic (water, oil) and nonmagnetic ones, can be efficiently transported using the moderate magnetic field (ca. 50 mT) produced by a small permanent magnet. Complex trajectories can be achieved in a reliable manner and multiplexing potential is demonstrated through on-demand drop fusion. Our paramagnetofluidic method advantageously works without any complex equipment or electric power, in phase with the necessary development of robust and low-cost analytical and diagnostic fluidic devices. [ABSTRACT FROM AUTHOR]

We study dynamic liquid bridge formation, which is relevant for wet granular flows involving highly viscous liquids and short collisions. Specifically, the drainage process of liquid adhering to two identical, non-porous wet particles with different initial film heights is simulated using Direct Numerical Simulations (DNS). We extract the position of the interface, and define the liquid bridge and its volume by detecting a characteristic neck position. This allows us building a dynamic model for predicting bridge volume, and the liquid remaining on the particle surface. Our model is based on two dimensionless mobility parameters, as well as a dimensionless time scale to describe the filling process. In the present work model parameters were calibrated with DNS data. We find that the proposed model structure is sufficient to collapse all our simulation data, indicating that our model is general enough to describe liquid bridge formation between equally sized particles. © 2016 American Institute of Chemical Engineers AIChE J, 62: 1877-1897, 2016 [ABSTRACT FROM AUTHOR]

The disintegration process of pharmaceutical solid dosage forms commences on contact with the dissolution medium and continues with subsequent spontaneous imbibition of the medium in the tablet matrix. Identifying the location of the liquid front in situ during imbibition, therefore, plays a significant role in understanding and modelling the disintegration process. Terahertz pulsed imaging (TPI) technology can be used to investigate this process by its ability to penetrate and identify the liquid front in pharmaceutical tablets. However, previous studies were limited to samples suitable for a flow cell environment, i.e. flat cylindrical disk shapes; thus, most commercial tablets could only be measured with prior destructive sample preparation. This study presents a new experimental setup named open immersion to measure a wide range of pharmaceutical tablets in their intact form. Besides, a series of data processing techniques to extract subtle features of the advancing liquid front are designed and utilised, effectively increasing the maximum thickness of tablets that can be analysed. We used the new method and successfully measured the liquid ingress profiles for a set of oval convex tablets prepared from a complex eroding immediate-release formulation. [Display omitted] [ABSTRACT FROM AUTHOR]

Transport is central for frost deterioration, though playing different roles before/after starting freeze/thaw. Liquid uptake (LU) during rapid freeze/thaw in water (RF) and frost/salt test (FS) and relations LU-scaling and -internal damage were investigated on non- and air-entrained (AE) concrete (w/b = 0.29–0.45, 50–130 MPa). 8–22 % of the air-voids became waterfilled during water-curing. Absorption during pre-saturation in FS correlated to initial scaling but without general LU - salt scaling correlation. LU (kg/m2) was lower in RF than in FS, indicating different transport/damage mechanisms. In RF, LU correlated to cracking and scaling (especially well-cured concrete). Air entrainment always reduced LU. FS to −52 °C increased both LU and scaling for internally damaged concretes compared to −20 °C but did not affect LU in undamaged well-cured concretes. Modelled and measured LU during RF correlated very well and indicates hydraulic pressure is more important than cryosuction for reducing LU in AE concrete. [ABSTRACT FROM AUTHOR]

Liquid transport process in gas-solid fluidized beds attracts many concerns, as it influences the fluidization dynamics and the distribution of liquid across the bed. This paper studied the liquid transport behaviors in a top-sprayed fluidized bed by incorporating bed conductance analysis, pressure fluctuation analysis and bubble image processing. The results show that liquid is trapped in agglomerates after being sprayed into the bed and then converts to free liquid accompanied by the disintegration of agglomerates. The free liquid spreads from the upper-middle bed, by the way of either sides, and finally arrives at the bottom bed. The free liquid content in the bed sharply increases and gradually saturates, as the disintegrating pattern of agglomerates changes from fracture to erosion. The liquid transport process accelerates when increasing the superficial air velocity and particle diameter, and slows down when increasing the liquid viscosity and surface tension. [Display omitted] • This work studies the liquid transport in fluidized bed via bed conductance analysis. • Liquid is trapped is agglomerates as being sprayed in bed initially. • Trapped liquid converts to free liquid with the disintegrations of agglomerates. • Increasing particle size accelerates the liquid transport process. • Liquid transport slows down when increasing liquid viscosity and surface tension. [ABSTRACT FROM AUTHOR]

Investigations in liquid sorption and transport were performed with three different variants of terry woven structures. Terry fabrics were produced using linen warp pile yarns and cotton or linen ground warps and wefts. The process of liquid sorption from the first moment when the water drop beads up the fabric's surface until there is a complete loss of the drop's specular reflectance and an absolute absorption of the liquid i.e., when the wetted spot remains stationary. A method for measuring dynamic water absorption in and through terry fabric is suggested. The action of terry fabric in contact with a liquid drop and liquid transport through it depends on the structural characteristics of the terry material, the kind of impact or finishing operation and its intensity. The character of liquid penetration through terry fabric is different when analysing grey woven material, and which is affected by intensive impact/finishing. All the kinds of regressions investigated generally showed a very good match with experimental data. The results of the research determined the dynamics and character of the sorption process in woven terry fabrics and could be used for creating new textiles with desired properties. [ABSTRACT FROM AUTHOR]

Internal mass transfer in a porous solid partially saturated with multicomponent liquids has been experimentally and theoretically studied. Isothermal drying experiments were performed using a jacketed wind tunnel where the transient composition profiles and total liquid content of a cylindrical sample were determined. Sand samples wetted with the ternary liquid mixtures water-methanol-ethanol and 2-propanol-methanol-ethanol were dried at two different initial compositions and temperatures. A mathematical model including mass transfer by capillary movement of the liquid and interactive diffusion in both gas and liquid phase was developed. To simulate the capillary movement of liquid mixtures, parameters experimentally determined for single liquids where weighed according to liquid composition. A fairly good agreement between theoretical and experimental liquid composition profiles was obtained provided that axial dispersion is included in the model. [ABSTRACT FROM AUTHOR]