Encapsulated porosity

Encapsulation of molecules into the inner porosity of a sol-gel matrix affords unprecedented molecular dispersion in a solid phase. 

The effects of moisture must be limited by ensuring that the residual porosity in ceramics consists of isolated pores so that water does not penetrate into the bulk. Units must be protected from humidity either by encapsulation in polymers with a low permeability to water vapour or by enclosure in sealed metal cans. 

Moreover, the inner cavity of supramolecular capsules provides a discrete, well-defined environment ideally suited to investigate effects of compartmentalization and processes in confined spaces [8]. To realize technical applications as detection and stabilization of encapsulated molecules or their use as nano-sized reaction vessels, precise control of important factors such as size, stability, porosity of the walls, and functionalization of the inner surface have to be achieved [9-18]. Several capsules have been synthesized and a proof of principle for several applications has been provided, but in most cases their use is restricted to small guest molecules. The development of spacious architectures which are able to encapsulate several bulky molecules and are amenable for decoration of the inner surface with functional groups will constitute an important step on the way to functional systems. 

The earlier literature contains several references to missing porosity, meaning the difference between mercury porosities and total water porosities. The difference clearly arises mainly from the failure of mercury to enter vacated interlayer space but has also been attributed to the encapsulation of gel by CH (D33) or to the presence of large (> 15 pm), closed pores that are not entered (A 15). 

Shock-recovery experiments were performed using a propellant gun (4> = 30 mm) at the National Institute for Materials Science. The projectile was a 4-mm-thick stainless-steel plate embedded in the front of a high-density polyethylene sabot. The annealed plagioelase with samarskite was encapsulated in a cylindrical container made of SUS304 stainless steel. In addition and for reference, starting plagioelase was also shock-loaded. It is well known that the peak pressure depends on the initial porosity of material [15]. Tlie samples were... 

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