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chemical nature and limited care about their further handling and deliv-ery; thus, product manufacturing for health care belongs to the fundamentaltechnological realm of Chemistry, in the sense above described. Chemistryis essentially a macroscopic science or technological field, and its successfuland reproducible results have fascinated mankind since ancient times. Here,

the accrued scientific knowledge on the structure and dynamics of materialsand reactions on the molecular scale allows the mass production of func-tional materials or ingredients. In these cases, a precise macroscopic controlof operational conditions (physical: temperature, pressure, velocity or resi-dence time; chemical: pH, concentrations, etc.) and the use of catalyzers,geometries or surface treatments is enough for a sufficient, massive yield orproduction. This has several cons, though. First, the inherently stochasticnature of chemical reactions leaves room for the presence of undesired sub-stances (by-products, reactants, etc.) in the final product (e.g., trans fatsin artificial fat hydrogenation [6]). Furthermore, the many degrees of free-

dom appearing in chemical processes provoke the overlapping of operationalranges leading to different products, whose selection or separation is eitherperformed through several secondary steps, or promoted ab initio by the useof specific catalyzers, different forms of the reactants, etc.

On the other hand, mechanical processes imply forces and energies onthe molecular scale exceedingly small compared to those necessary to triggerchemical reactions. Chemistry often makes use of mechanical processes anddevices to provide limiting frameworks to chemical reactions and minimizethe above mentioned handicaps, without changing the chemical nature orreactants. Reducing bulk reactants or ingredients to granular matter is atypical mechanical preparatory step in chemistry; however, granular form

can show an immense variety of features. Here, fundamental parameters arethe size, shape and homogeneity of grains or particles. First, particle sizedetermines the surface-to-volume ratio of a bulk material when particles arenot too different from a spherical shape; second, size homogeneity reflectshow that surface-to-volume ratio is distributed, and third, particle shape isanother fundamental ingredient of surface-to-volume ratio which affects notonly the chemical reaction rate but also mechanical steps like self-assemblyand patterning, which provide endless possibilities [7, 8, 9, 10]. Since inthis work we review a fundamental aspect of material functionality providedby geometry of matter constituents, a brief summary of geometrical issuespertaining shape, surface area and volume is given below.

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