Electrostatic Encapsulated

Figure 94. Schematic representation of the principle of electrostatic encapsulation...

In addition to the processes described above, there are many other encapsulation processes [Thies, 204] which are in use or are under various stages of development. These include phase inversion in polymer solution, pan coating, solvent evaporation, gelation, electrostatic encapsulation, and vapor deposition. 

In the electrostatic encapsulation process, a core material and an immiscible liquid coating phase are converted into oppositely charged aerosols so that the core phase (having higher surface tension) is surrounded by a shell of the coating phase, which is then hardened by a suitable means, forming small microcapsules. 

Fig. 3. NAMD 1 employs a modular, object-oriented design in which patches communicate via an encapsulated communication subsystem. Every patch owns an integrator and a complete set of force objects for bonded (BondForce), nonbonded (ElectForce), and full electrostatic (DPMTA) calculations.

Recently, we proposed an alternative process for encapsulating biomacromolecules within PE microcapsules. This approach involves using nanoporous particles as sacrificial templates for both enzyme immobilization and PE multilayer capsule formation (Figure 7.2, route (I)) [66,67]. Unlike previous LbL encapsulation strategies, this approach is not limited to species that undergo crystallization, and is not dependent upon adjustments in electrostatic interactions within PE microcapsules to alter shell permeability characteristics. The salient feature of this method is that it is applicable to a wide range of materials for encapsulation. 

The enzymes are stabilized due to hydrogen-bonding and electrostatic interactions with NH and SiOH groups. Furthermore, the gels retain a significant amount of water necessary for the stability of the encapsulated biomolecules. As a result, almost all of the enzyme (Kl, 94% K3, 98% K4, 100% K5, 100%) is stable and is released from the gels when placed... 

The emission of the metal particles may thus originate from a band-to-band transition in the metal particle, which occurs at about 516 nm for gold [60, 119]. As stated above, the nature of the interaction of the dendrimer (PAMAM) host is still uncertain, there could be very strong electrostatic interactions that may play a part in the enhancement of the metal particles quantum efficiency for emission. However, one would expect that this enhancement would result in slightly distorted emission spectra, different from what was observed for the gold dendrimer nanocomposite. Further work is necessary to completely characterize the manner in which the dendrimer encapsulation enhances the emission of the metal nanoparticles. With further synthetic work in preparation of different size nanoparticles (in other words elongated and nonspherical shape particles, including nanorods) it may be possible to develop the accurate description of a... 

The possibility of using electrostatic charge attraction has been exploited in the preparation of gold dendrimer encapsulated nanoparticles (DENs), which under appropriate conditions can be fully distributed along the surface of monodispersed MWCNTs (Fig. 3.21) [103]. 

Zhou, X.S., et al., Self-assembled nanocomposite of silicon nanoparticles encapsulated in graphene through electrostatic attraction for lithium-ion batteries. Advanced Energy Materials, 2012. 2(9) p. 1086-1090. 

---