intended to have the meanings commonly understood by those of skill in the art to which this invention pertains the term u201c about u201d as used in connection with a numerical value throughout the description and the claims denotes an interval of accuracy familiar and acceptable to a person skilled in the art said interval is u00b1 10 u201c average size u201d is used in connection with a nanoparticle or a particle to denote the average of the size the definition is based on replacing a given irregularly shaped particle with an imaginary sphere that has the volume identical with the irregularly shaped particle this volume based particle size equals the diameter of the sphere that has same volume as a given irregularly shaped particle u201c hygroscopic u201d is used herein to denote the ability of a substance to attract water molecules or molecules with similar properties as water from the surrounding environment through either absorption or adsorption u201c hydrophobic u201d is used herein to denote the property of being water repellent tending to repel and not absorb water u201c nanoparticle u201d is used herein to denote a localized object with a volume and a mass in particular u201c nanoparticle u201d is used to denote particles which form the coating of the ncs particle u201c nanoparticles u201d are thus smaller than the ncs particle u201c ncs particle u201d is used herein to denote a localized object with a volume and a mass in particular u201c particle u201d and or u201c ncs particle u201d is used to denote an object comprising a salt which object is coated with very small particles called nanoparticles thus the word u201c particle u201d may refer to an object comprising an inner.