Droplet-in-matrix phase

Droplet-in-Matrix Phase Morphology (Dispersed Morphology)... 

An illustration of a composite (encapsulated droplet-in-matrix) phase morphology in melt-blended ternary blend 70 wt% polyamide/15 wt% polystyrene/15 wt% polypropylene. The droplet is polypropylene, the encapsulating phase is polystyrene, and the matrix is polyamide. (From G. Lei, Development of Three Phase Morphologies in Reactively Compatihilized Polyamide 6/Polypropylene/Polystyrene Ternary Blends, master s thesis, Katholieke Universiteit Leuven, Belgium, 2004.)... 

A droplet-in-matrix phase morphology developed in immiscible polymer blends depends on the viscoelastic properties and composition of the two components of the blend in the melt state. The rheological formalism used for the non-Newtonian phases as polymer melts follows, with adjustment of the... 

There exist in polymer blends two or three major types of phase morphologies, depending on whether the encapsulated structures (composite droplets) are considered as a class apart. The most common is the droplet-in-matrix (as, for example, Figure 1.3), the (droplet-in-droplet)-in-matrix (as, for example. Figure 1.4), and the cocontinuous phase morphology where both phases are mutually interconnected throughout the whole volume of the blend (as, for example. Figures 1.5 and 1.6). 

Contrary to the droplet-in-matrix, the mechanism and the control of the co-continuous phase morphology, where the two phases are continuous and interconnected throughout the whole volume of the blend, is still not well elucidated. The complexity arises mainly from the ambiguous effect of the viscoelastic characteristics of the components, their composition in the blends, and the magnitude of their interfacial tension. Several empirical expressions have been proposed so far to predict either the phase inversion or the conditions for which co-continuous morphology is generated. 

We decided to rank apart the phase morphology in ternary immiscible blends because it can be droplet-in-matrix, co-continuous, or a mixture of both and, in many situations, an encapsulated droplet-in-matrix structure. 

Wood Hill (1991b) induced phase-separation in the clear glasses by heating them at temperatures above their transition temperatures. They found evidence for amorphous phase-separation (APS) prior to the formation of crystallites. Below the first exotherm, APS appeared to take place by spinodal decomposition so that the glass had an intercoimected structure (Cahn, 1961). At higher temperatures the microstructure consisted of distinct droplets in a matrix phase. 

Other Aluminosilicates, Transparent mullite glass-ceramics can be produced from modified binary Al C —Si02 glasses (21). In these materials, the bulk glass phase separates into tiny alumina-rich droplets in a siliceous matrix. Further heat treatment causes these droplets to crystallize to mullite spherulites less than 0.1 Jim in size. When doped with ions such as Cr3+, transparent mullite glass-ceramics can be made to absorb broadly in the visible while fluorescing in the near-ii (22,23), thereby making them potentially useful for luminescent solar collectors. 

Often interfaces and colloids are discussed together. Colloids are disperse systems, in which one phase has dimensions in the order of 1 nm to 1 pm (see Fig. 1.1). The word colloid comes from the Greek word for glue and has been used the first time in 1861 by Graham1. He applied it to materials which seemed to dissolve but were not able to penetrate a membrane, such as albumin, starch, and dextrin. A dispersion is a two-phase system which is uniform on the macroscopic but not on the microscopic scale. It consists of grains or droplets of one phase in a matrix of the other phase. 

The pressure of a fast turnaround time for the expensive LC-MS instrument and false confidence in MS mass resolution power often leads to compromised methods with shortened chromatographic runs. With limited sample clean-up for macromolecules and inadequate chromatographic separation, matrix components can co-elute with the analyte. They may compete for the limited charge or impede (or promote) movement of the analyte ions to the surface of the droplets, resulting in matrix effects [54]. Matrix effects can impact on selectivity, sensitivity, linearity and reproducibility of the assay. For ESI, competition for ionization can occur both in the mobile phase and the gas phase [55]. The pH, volatility, and surface tension of the mobile phase will affect ionization efficiency. The major suppres-... 

These direct ion sources exist under two types liquid-phase ion sources and solid-state ion sources. In liquid-phase ion sources the analyte is in solution. This solution is introduced, by nebulization, as droplets into the source where ions are produced at atmospheric pressure and focused into the mass spectrometer through some vacuum pumping stages. Electrospray, atmospheric pressure chemical ionization and atmospheric pressure photoionization sources correspond to this type. In solid-state ion sources, the analyte is in an involatile deposit. It is obtained by various preparation methods which frequently involve the introduction of a matrix that can be either a solid or a viscous fluid. This deposit is then irradiated by energetic particles or photons that desorb ions near the surface of the deposit. These ions can be extracted by an electric field and focused towards the analyser. Matrix-assisted laser desorption, secondary ion mass spectrometry, plasma desorption and field desorption sources all use this strategy to produce ions. Fast atom bombardment uses an involatile liquid matrix. 

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