Dried layer, thickness

Variation of product resistance with concentration is illustrated by the data in Fig. 4, where values of the mean product resistance, (Rp), are given for various product types at different total solute concentrations. The mean product resistance is the mean resistance over a dry layer thickness interval of 0-1 cm. The scatter reflects formulation-specific effects whereas the... 

Fig. 3.19 Water vapor mass transfer resistance versus freeze-dried layer thickness. Continuous line = model prediction, according to Hottot et al. (2005).

From the above relationship, it is possible to estimate the experimental values of K from experimental values of the primary drying rate, denoted by m, over the sublimation period corresponding to the freeze-dried layer thickness, Idry, by the following relationship ... 

The experimental values of permeability, Kejip, plotted in Fig. 3.20 correspond to mean values of dried layer thickness, of about 3 and 4 mm for the mannitol and... 

A copolymer of NiPAAm with 1 mol% of a vinyl monomer carrying a protected isocyanate group was used by Hiiata, Okazaki, and Iwata (2004) to fabricate cross-Unked coatings. Upon heat treatment at 150 °C for 1.5 h, the isocyanate group is deprotected and cross-links to the amide group of the NiPAAm unit. A dry layer thickness of 35 nm was obtained, but higher values are possible. Given that the substrate... 

Equations 5.11-5.13 can be used to calculate the interface temperature, once the operating conditions (temperature and humidity of the air stream) have been selected, and the values of the heat and mass transfer coefficients have been determined (see, among others, Boeh-Ocansej, 1988 Krokida et al., 2002). It is then possible to calculate the sublimation flux and, finally, the variation of the dried layer thickness with time ... 

Compared to DMAEMA, there are only a few reports on the ATRP of DEAEMA polymer brushes [20,52,53]. Our efforts involved the SC-ATRP of PDEAEMA from silanized silicon (Si) wafer substrates, and different catalyst (CuBr, CuCl), initiator (Si-Br, Si-Cl), solvent (IPA/H2O, methanol, toluene, THE, anisole), and reaction temperature (25°C-90°C) combinations were examined. The thickest PDEAEMA brushes were obtained using CuCl/ CUCI2/HMTETA as the catalyst system with a 2-bromoisobutyryl-based initiator, MeOH as the solvent, and a reaction temperature of 60°C. Under these conditions, the maximum PDEAEMA dry layer thickness obtained was 19 nm after polymerization for 72 h. 

Currently, there has been only one report in the literature concerning ATRP of 2-(dimethylamino)ethyl acrylate (DMAEA) which involved homogeneous (bulk) polymerization (instead of polymer brush) formation [54]. To the authors knowledge, the only LRP technique applied in the s)mthe-sis of PDMAEA polymer brushes is nitroxide-mediated radical polymerization [55-57]. The first synthesis of PDMAEA brushes from Si substrates by SC-ATRP used a CuCl/CuCl2/Me6TREN/2-bromopropionyl type initiator catalyst system and reaction temperature of 70°C. PDMAEA dry layer thicknesses reached 34 5.9 nm after 72 h. 

Based on this equation, the interface temperature is calculated, depending on the values of the operating conditions (e.g. gas and droplet temperature), the heat and mass transfer coefficients, product particle parameters and Added and also the dried layer thickness [30]. Thereby, it is possible to calculate the subhmation flow rate (using (10.16)) and the temporal evolution of the dried volume ... 

While pure collagen provided a dry layer thickness of about 80 run, significantly thinner layers in the range between 14 and 32 nm (for fixed, pre-set refractive index values) were measured if heparin or hyaluronic acid were added to fibril-forming solutions (Table 3). The quantification of surface-bound proteins confirmed the results of the elUpsometric measurements noticeable lower collagen amoimts were quantified if fibril formation and immobilization was performed in the presence of glycosaminoglycans. The quantification was supported by surface topographic analysis of the attached fibrillar components (Fig. 7). 

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