Mixed transition metal oxides silica xerogels as antifouling/fouling release surfaces

A method of providing a thin film xerogel coating on a surface comprising:

• applying a sol-gel composition comprising:
• i) 0.25 mole % to 50 mole % of a transition metal alkoxide and/or transition metal oxide, and
• 50 to 99.75 mole % of a tetraalkoxysilane, with the proviso that the total mol % of the transition metal alkoxide and/or transition metal oxide and tetraalkoxysilane does not exceed 100 mol %, or
• ii) 0.25 mole % to 25 mole % of a transition metal alkoxide,
• 45 mole % to 90 mole % of a tetraalkoxysilane, and
• 10 mole % to 55 mole % of a C1-C12 alkyltrialkoxysilane, or
• iii) 0.25 mole % to 25 mole % of a transition metal alkoxide and/or a transition metal oxide,
• 45 mole % to 90 mole % of a tetraalkoxysilane, and
• 10 mole % to 55 mole % of an aminoalkyl-, alkylaminoalkyl-, or
• dialkylaminoalkyltrialkoxysilane, with the proviso that the total mol % of the transition metal alkoxide and/or transition metal oxide and tetraalkoxysilane and C1-C12 alkyltrialkoxysilane, if present, and the aminoalkyl-, alkylaminoalkyl-, or dialkylaminoalkyltrialkoxysilane, if present, does not exceed 100 mol %,
• to the surface such that the thin film xerogel coating having a thickness of 1 to 20 microns is formed on the surface.

A method of using a surface susceptible to fouling in a marine environment comprising:

• applying a sol-gel composition comprising:
• i) 0.25 mole % to 50 mole % of a transition metal alkoxide and/or a transition metal oxide, with the proviso that the total mol % of the transition metal alkoxide and/or transition metal oxide and tetraalkoxysilane does not exceed 100 mol %, and 50 to 99.75 mole % of a tetraalkoxysilane, or
• ii) 0.25 mole % to 25 mole % of a transition metal alkoxide,
• 45 mole % to 90 mole % of a tetraalkoxysilane, and
• 10 mole % to 55 mole % of a C1-C12 alkyltrialkoxysilane, or
• iii) 0.25 mole % to 25 mole % of a transition metal alkoxide and/or a transition metal oxide,
• 45 mole % to 90 mole % of a tetraalkoxysilane, and
• 10 mole % to 55 mole % of an aminoalkyl-, alkylaminoalkyl-, or
• dialkylaminoalkyltrialkoxysilane, with the proviso that the total mol % of the transition metal alkoxide and/or transition metal oxide and tetraalkoxysilane and C1-C12 alkyltrialkoxysilane, if present, and the aminoalkyl-, alkylaminoalkyl-, or dialkylaminoalkyltrialkoxysilane, if present, does not exceed 100 mol %,
• to the surface such that the thin film xerogel coating having a thickness of 1 to 20 microns is formed on the surface, and
• exposing the thin film xerogel coated surface to the marine environment,
• wherein the thin film xerogel coated surface exhibits reduced fouling relative to a same surface that is not coated with the thin film xerogel coating or non-observable fouling after contact with the marine environment.

A composition comprising a transition metal oxide and silicon oxide xerogel matrix,

• wherein the xerogel matrix is formed from a sol-gel composition comprising:
• 0.25 mole % to 25 mole % of a transition metal alkoxide and/or a transition metal oxide, and
• 45 mole % to 90 mole % of a tetraalkoxysilane, and
• wherein the sol-gel composition further comprises:
• 10 mole % to 55 mole % of a C1-C12 alkyltrialkoxysilane or
• 10 mole % to 55 mole % of an aminoalkyl-, alkylaminoalkyl-, or
• dialkylaminoalkyltrialkoxysilane, with the proviso that the total mol % of the transition metal alkoxide and/or transition metal oxide and tetraalkoxysilane and C1-C12 alkyltrialkoxysilane, if present, and the aminoalkyl-, alkylaminoalkyl-, or dialkylaminoalkyltrialkoxysilane, if present, does not exceed 100 mol %,
• wherein the aminoalkyl-, alkylaminoalkyl-, or dialkylaminoalkyltrialkoxysilane is selected from the group consisting of aminopropyltriethoxysilane (AP or APTES), methylaminopropyltriethoxysilane (MAP), or dimethylaminopropyltriethoxysilane (DMAP), and combinations thereof.

A composition comprising a transition metal oxide and silicon oxide xerogel matrix,

• wherein the xerogel matrix is formed from a sol-gel composition comprising:
• 0.25 mole % to 25 mole % of a transition metal alkoxide and/or a transition metal oxide, and
• 45 mole % to 90 mole % of a tetraalkoxysilane, and
• wherein the sol-gel composition further comprises:
• 10 mole % to 55 mole % of a C1-C12 alkyltrialkoxysilane or
• 10 mole % to 55 mole % of an aminoalkyl-, alkylaminoalkyl-, or
• dialkylaminoalkyltrialkoxysilane, with the proviso that the total mol % of the transition metal alkoxide and/or transition metal oxide and tetraalkoxysilane and C1-C12 alkyltrialkoxysilane, if present, and the aminoalkyl-, alkylaminoalkyl-, or dialkylaminoalkyltrialkoxysilane, if present, does not exceed 100 mol %,
• wherein the transition metal alkoxide is selected from the group consisting of titanium tetraisopropoxide (TTIP), oxovanadium triisopropoxide (VOTIP), or tungsten pentaisopropoxide (WPIP), and combinations thereof and/or the transition metal oxide is selected from vanadium oxide (V2O5).

A composition comprising a transition metal oxide and silicon oxide xerogel matrix,

• wherein the xerogel matrix is formed from a sol-gel composition comprising:
• 0.25 mole % to 25 mole % of a transition metal alkoxide and/or a transition metal oxide, and
• 45 mole % to 90 mole % of a tetraalkoxysilane, and
• wherein the sol-gel composition further comprises:
• 10 mole % to 55 mole % of a C1-C12 alkyltrialkoxysilane or
• 10 mole % to 55 mole % of an aminoalkyl-, alkylaminoalkyl-, or
• dialkylaminoalkyltrialkoxysilane, with the proviso that the total mol % of the transition metal alkoxide and/or transition metal oxide and tetraalkoxysilane and C1-C12 alkyltrialkoxysilane, if present, and the aminoalkyl-, alkylaminoalkyl-, or dialkylaminoalkyltrialkoxysilane, if present, does not exceed 100 mol %,
• wherein iii) the tetraalkoxysilane is selected from the group consisting of tetramethoxysilane (TMOS), tetraethoxysilane (TEOS), or tetraisopropoxysilane (TIPOS), and combinations thereof.