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Master Sizer

Liquid carbon dioxide (purity 99, 95 Vol %) was undercooled (W2) to avoid cavitation in the membran pump (P). After the compression to pre-expansion pressure, the fluid is heated to the extraction temperature (W3). The supercritical fluid loaded with anthracene leaves the extractor (V = 0,6 1). With a additional heat exchanger (W4), the solution is heated to pre-expansion temperature. In the separation vessel, the supercritical solution is expanded through a nozzle. The expanded gas will be condensed (Wl) and recompressed or let off. After the experiment, the separation vessel is opened and the particles were collected. The particle size is measured by laser diffraction spectroscopy (Malvern Master Sizer X). [Pg.370]

The best method of the determination of the particle size distribution of the different crospovidone types is the light diffraction measurement (e.g. Malvern Master Sizer, see Fig. 63 and 64). The particle size distribution of normal crospovidone also can be measured by sieving or air jet screening. In this dry sieving method more than 50 % of the particles are coarser than 50 pm without any swelling. Therefore even with this dry method it corresponds clearly to the definition of Type A of the Ph.Eur. monograph. [Pg.128]

The particle size distribution of micronized crospovidone can be measured as suspension in water or cyclohexane by a Malvern Master Sizer and there is no significant influence of the solvent. If almost all particles are finer than 50 pm it is classified as Type B of Ph.Eur. [Pg.128]

Fig. 63. Particle size distribution of the normal grades of crospovidone available in the market (Method Malvern Master Sizer)... Fig. 63. Particle size distribution of the normal grades of crospovidone available in the market (Method Malvern Master Sizer)...
Emulsions are prepared using various ratios of the two surfactants. The total surfactant concentration is kept constant (e.g., 10%) based on the oil phase typically, for a 50 50 emulsion, 5% surfactant is used. The emulsions are placed in cylinders and their stability is assessed by visual inspection (looking for any oil separation), by droplet size analysis (e.g., using a Malvern Master Sizer), and by measuring the interfacial tension. For an 0/W emulsion the stability, droplet size and interfacial tension are plotted as a function of the % surfactant with a high HLB number. The stability reaches a maximum at an optimum % of the surfactant with the high H LB number, and at this optimum ratio the droplet size and interfacial tension reach a minimum. For W/O emulsions, the stability droplet size and interfacial tension are plotted versus % surfactant with a low FI LB number. The stability reaches a maximum at an optimum % of the surfactant with the low H LB number, and at this optimum ratio the droplet size and interfacial tension reach a minimum. [Pg.319]

Figure 19.7 Single measurement of a mixture of six standard lattices using the Master Sizer. Figure 19.7 Single measurement of a mixture of six standard lattices using the Master Sizer.
To obtain a measure of the rate of crystal growth, the particle size distribution of the suspension is followed as a function of time, using either a Coulter counter, a Master Sizer or an optical disc centrifuge. Usually, the cube of the average radius is plotted versus time this gives a straight Hne from which the rate of crystal growth can be determined (the slope of the linear curve). [Pg.420]

Provided that the emulsion does not undergo any flocculation, the coalescence rate can be measured simply by following the number of droplets or average diameter as a function of time. For this, a given volume of the emulsion is carefully diluted into the Isotone solution of the Coulter counter, and the number of droplets is measured. The average diameter can be obtained using laser diffraction methods (e.g., with the Master Sizer). By following this procedure at various time periods, the coalescence rate constant K can be obtained. [Pg.460]

Some of these develc nnents are st towards "in-line or on-line analysis [128-131]. Malvern offers a Master Sizer (36(X) EQ for this use, as does Particle Sizing Systems (NKTOMP 370 L), and Leeds Nordmip (Micro Trac SRA-1(X)). Insitec markets three specific in-line instrum its for particle measurement in the range 0.5-1500 pm, but these are used primarily on powdered materials or... [Pg.227]

The break-up of Newtonian liquids with various viscosities t] can be investigated by mastication of small oil samples and measuring the resulting droplet size distribution, using a Coulter Counter or a Master sizer. Samples are expectorated into a suitable surfactant solution, e.g. Tween (to prevent coalescence during measurements). can be measured at 37 °C (body temperature) using a suitable rheome-... [Pg.621]

The change of average particle size with time of grinding is established using for example the Master Sizer. Figure 4.12 shows a schematic representation of the reduction of particle size with grinding time in minutes using a typical bead mill (see below) at various volume fractions. [Pg.322]


See other pages where Master Sizer is mentioned: [Pg.251]    [Pg.172]    [Pg.394]    [Pg.413]    [Pg.414]    [Pg.460]    [Pg.460]    [Pg.12]    [Pg.418]    [Pg.486]    [Pg.557]    [Pg.624]    [Pg.61]    [Pg.83]    [Pg.226]    [Pg.320]    [Pg.388]    [Pg.390]   
See also in sourсe #XX -- [ Pg.394 , Pg.414 ]

See also in sourсe #XX -- [ Pg.322 ]




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