Nanocomposite containing hollow silica spheres functionalized with azole silanes

A nanocomposite, comprising a silanization reaction product of:

• a hollow silica sphere comprising a silica-containing shell surrounding a core;
• and
• an azole-functionalized silane linker,
• wherein:
• the silica-containing shell has a higher density of silica compared to the core;
• the hollow silica sphere has an average diameter of 300-900 nm;
• the azole-functionalized silane linker is a ring-opening reaction product of:
• a coupling agent of formula (I)
• and
• an azole moiety selected from the group consisting of 1H-1,2,4-triazole, 3-amino-1,2,4-triazole, and 5-aminotetrazole,
• wherein:
• R1 and R2 are independently an optionally substituted C1-C6 alkoxy;
• R3 is selected from the group consisting of an optionally substituted C1-C6 alkoxy, an optionally substituted alkyl, and an optionally substituted cycloalkyl;
• m is an integer in a range of 2-10;
• and
• n is an integer in a range of 1-6, and
• a weight ratio of the hollow silica sphere to the azole-functionalized silane linker is in a range of 2:1 to 50:1.