Microcapsule micrograph

Fig. 1—Scanning electron micrograph of an individual microcapsule showing plates of DL-PLA on the surface (coret coat ratio, 1 1).

The appearance of the individual microcapsules is shown in Fig. 1. Most individual microcapsules are approximately spherical and show a surface made up of deposited plates of poly(DL-lactic acid) in which the drug is embedded. Many of the larger microcapsules are cemented together by further plates of poly(DL-lactic acid). The effect of compression on these microcapsules is shown in Fig. 2. At a compressive force of 2 kN (Fig. 2(a)) the electron micrograph of the tablet fracture surface shows that the microcapsules, while distorted, remain essentially intact and rounded, with a relatively open porous structure to the tablet as a whole. At 10 kN force (Fig. 2(b)) the microcapsules at the fracture are flattened, cracked and distorted so that the fracture surface shows a far less open, porous aspect. Both of these microcap tablets have a very different appearance from that produced by the simple mixture (Fig. 3), where the individual plates of poly(DL-lactic acid) are mixed with the drug crystals in an open structure from which release would be easily... 

Figure 2.3 Scanning electron micrographs of fish oil microcapsules which were microencapsulated with different concentrations of sugar beet pectin (A and D 1.1% B and C 2.2%) and different oil loads (A and C 50% B and D 20%). Reproduced from Dmsch (2007) with permission.

Figure 2.2 Electron micrograph of microcapsules on filter paper (lOOOx). (From Morgan, R.L., et al., in Pesticide Formulations Innovations and Developments, Cross, B. and Scher, H.B., Eds., ACS Symposium Series 371, American Chemical Society, Washington, D.C., 1988, p. 131. With permission.)...

Additionally, microcapsules coated with gold nanoparticles (to give increased contrast for identification in the electron micrograph) have been investigated in rat liver with electron microscopy before and after application of ultrasound (yellow arrows). Only fragments of shells can be identified in tissue post-ultrasound. 

Fig. 1.6 SEM micrograph of PLG-microcapsules containing human serum albumin (left) and cytochrome C (right) as model drug.

Based on the high number of preserved, intact microcapsules in the case of the washed thermochromic textile, the colouristic parameters alone could not be used to evaluate the functionality of the thermochromic textile, while the SEM micrographs suggest the presence of a sufficient number of preserved microcapsules to retain the thermochromic property (Figure 2.23). 

SEM micrographs confirmed that the microcapsules were least prone to degradation by rubbing (friction), considering the quite significant number of microcapsules that remained perfectly spherical in shape (Figure 2.24). 

FIGURE 3 Electron micrograph of ultrathin sections of polyelectrolyte microcapsules containing ferritin at pH 2. The polyelectrolyte shell of the composition is (PSS/PAA)3. 

Figure 14 (a) Fluorescence micrograph of solid microcapsules dried from a copolymer 43 (with n= 50, m= 500) dispersion (excitation wavelength 540 nm). (b) Scanning electron microscopy image of microcapsules from a copolymer 43 (with n=50, m=250) solution dried at 25°C and coated with a 10 nm gold layer. Reprinted with permission from Chen, X. L. Jenekhe, S. A. Macromolecules 33.4610-4612, Copyright 2000 American Chemical Society. ... 

EC microcapsules containing Rosemary oil or limonene were obtained by phase separation method. According to this procedure, EC microcapsules without oil could also be produced. This could be explained due to EC inter cial activity, which stabilizes the formed emulsion. Surfactant-fiee multiple emulsions using EC as a polymeric emulsifier have already been reported by Melzer and collaborators [8]. From the scanning electron micrographs shown in Fig. 1 it is observed that EC microc g)sules had regular spherical sh, the size of microcapsules varied and that the surface was porous. 

Figure 254 Cells enclosed in chitosan/calcium alginate microcapsules prepared by complex coacervation. Micrographs obtained by optical microscopy at 60X. Reproduced with permission from Reference [162].

Figure 1.10 Scanning electron micrograph of silicone microcapsules containing an aqueous solution of self-tanning composition (Courtesy G. Habar, Microcapsules-Technologies).

FigureS.1 Scanning electron micrographs of microcapsules containing monocrotophos (a,b) and those from which monocrotophos has been extracted (c) [16].

Figure 5.9 SEM micrographs of the cellulose textile linked to chitosan microcapsules containing grapefruit seed extract (Alonso et al., 2010).

Fig. 11. Scanning electron micrograph of commercial NaCl microcapsules with a lipid coating produced by fluidized-bed coating. Magnification x.

Fig ure 5.60 Left preparation of enzyme filled poly(pyrrole) nanotubes sealed on one side. Right scanning electron micrograph showing microcapsules that were not attached to the epo glue surface. 

Figure 3.7 Micrograph of external view of polymeric microcapsules obtained from a polymeric solution containing 3% PSf in DMF and precipitated in water as a nonsolvent.

Figure 8.8 Temperature-sensitive hydrogel microcapsule for pulsed release of droplets, (a) Optical micrograph of a microcapsule with a shell comprised of a thermosensitive PNIPAm hydrogel containing aqueous droplets dispersed in oil. b—e) Optical micrograph time series showing the forced expulsion of the oil and water droplets contained within the microcapsule when the temperature is increased...

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