In an embodiment, the “precipitation retarding compound” comprises a group comprising a nitrogen atom, preferably a nitrogen atom present in a positively charged state. Preferably, the nitrogen containing group is represented by the letter “W”, for example as defined elsewhere in this specification. Exemplary groups may be selected from —NH₃⁺, —NH—C(NH₃⁺)═NH, and —N═CH—NH₃⁺. The compound preferably comprises an ammonium group.

In an embodiment, said “precipitation retarding compound” comprises a linker or spaceholder moiety (R¹), connecting said anchoring group and said preferably positively charged group, for example said positively charged nitrogen atom.

In an embodiment, said linker moiety is preferably an organic moiety comprising 1-20 carbons and 0-10 heteroatoms, preferably 2-12 carbons and 0-7 heteroatoms, more preferably 3-10 carbons and 0-5 heteroatoms, and most preferably 4-8 carbons and 0 heteroatoms. Said organic moiety may be totally or partially halogenated, in addition to said heteroatoms.

In an embodiment, said linker moiety is preferably a C1-C20 hydrocarbon, preferably a C2-C15 hydrocarbon, more preferably a C3-C12 hydrocarbon, and most preferably a C4-C8 hydrocarbon.

In an embodiment, said linker moiety is preferably selected from the group consisting of a C1-C20 alkanediyl, C2-C20 alkynediyl, C2-C20 alkynediyl, C4-C20 heteroaryldiyl, and C6-C20 aryldiyl, preferably C2-C15 alkanediyl, C2-C15 alkynediyl, C2-C15 alkynediyl, C4-C15 heteroaryldiyl, and C6-C15 aryldiyl, more preferably C3-C12 alkanediyl, C3-C12 alkynediyl, C3-C20 alkynediyl, C4-C12 heteroaryldiyl, and C6-C12 aryldiyl, most preferably C4-C8 alkanediyl, C4-C8 alkynediyl, C4-C8 alkynediyl, C4-C8 heteroaryldiyl, and C6-C8 aryldiyl.