Porous inorganic/organic hybrid monolith materials for chromatographic separations and process for their preparation

A method of preparation of a porous inorganic/organic hybrid monolith material, comprising porous inorganic/organic hybrid particles that have a chromatographically-enhancing pore geometry, comprising the steps of

• a) forming porous inorganic/organic hybrid particles,
• b) modifying the pore structure of said porous hybrid particles,
• c) surface modifying said porous hybrid particles, and
• d) coalescing said porous hybrid particles to form a monolith material,
• wherein said particles have been surface modified by a surface modifier selected from the group consisting of an organic group surface modifier, a silanol group surface modifier, a polymeric coating surface modifier, and combinations thereof.

A chromatographic column having improved lifetime, comprising

• a) a column having a cylindrical interior for accepting a monolith material of porous inorganic/organic hybrid material, and
• b) a chromatographic bed comprising a porous inorganic/organic hybrid monolith material having a chromatographically-enhancing pore geometry of the formula SiO2/(R2pR4qSiOt)n or SiO2/[R6(R2rSiOt)m]n wherein R2 and R4 are independently C1-C18 aliphatic, styryl, vinyl, propanol, or aromatic moieties, R6is a substituted or unsubstituted C1-C18 alkylene, alkenylene, alkynylene or arylene moiety bridging two or more silicon atoms, p and q are 0, 1 or 2, provided that p+q=1 or 2, and that when p+q=1, t=1.5, and when p+q=2, t=1;
• r is 0 or 1, provided that when r=0, t=1.5, and when r=1, t=1;
• m is an integer greater than or equal to 2, and n is a number from 0.03 to 1.

A method of preparation of a porous inorganic/organic hybrid monolith material, comprising coalesced porous particles of hybrid silica having a chromatography-enhancing pore geometry, comprising the steps of

• a) prepolymerizing a mixture of one or more organoalkoxysilanes and a tetraalkoxysilane in the presence of an acid catalyst to produce a polyorganoalkoxysiloxane;
• b) preparing an aqueous suspension of said polyorganoalkoxysiloxane, said suspension further comprising a surfactant or combination of surfactants, and gelling in the presence of a base catalyst so as to produce porous hybrid particles;
• c) modifying the pore structure of said porous hybrid particles by hydrothermal treatment;
• and
• d) coalescing said porous hybrid particles to form a monolith material thereby preparing a porous inorganic/organic hybrid monolith material.

A porous inorganic/organic hybrid monolith material comprising coalesced porous hybrid particles of hybrid silica having a chromatographically-enhancing pore geometry, produced by the process of

• a) prepolymerizing a mixture of one or more organoalkoxysilanes and a tetraalkoxysilane in the presence of an acid catalyst to produce a polyorganoalkoxysiloxane;
• b) preparing an aqueous suspension of said polyorganoalkoxysiloxane, said suspension further comprising a surfactant or a combination of surfactants, and gelling in the presence of a base catalyst so as to produce porous hybrid particles;
• c) modifying the pore structure of said porous hybrid particles by hydrothermal treatment;
• and
• d) coalescing said porous hybrid particles to form a monolith material.

A method of preparation of a porous inorganic/organic hybrid monolith material having a chromatographically-enhancing pore geometry, comprising the steps of

• a) forming a porous inorganic/organic monolith material,
• b) modifying the pore structure of said porous monolith material, and
• c) modifying the surface of said porous monolith material,
• wherein said monolith material has been surface modified by a surface modifier selected from the group consisting of an organic group surface modifier, a silanol group surface modifier, a polymeric coating surface modifier, and combinations thereof.

A method of preparation of a porous inorganic/organic hybrid monolith material having a chromatographically-enhancing pore geometry comprising

• a) preparing an aqueous solution of a mixture of one or more organoalkoxysilanes and a tetraalkoxysilane in the presence of an acid catalyst, and a surfactant or combination of surfactants to produce a polyorganoalkoxysiloxane;
• b) incubating said solution, resulting in a three-dimensional gel having a continuous, interconnected pore structure,
• c) aging the gel at a controlled pH and temperature to yield a solid monolith material,
• d) rinsing the monolith material with an aqueous basic solution at an elevated temperature,
• e) modifying the pore structure of said monolith material by hydrothermal treatment,
• f) rinsing the monolith material with water followed by a solvent exchange, and
• g) drying the monolith material at room temperature drying and at an elevated temperature under vacuum.
• thereby preparing a porous inorganic/organic hybrid monolith material.

A porous inorganic/organic hybrid monolith material having a chromatographically-enhancing pore geometry, produced by the process of

• a) preparing an aqueous solution of a mixture of one or more organotrialkoxysilanes and a tetraalkoxysilane in the presence of an acid catalyst, and a surfactant or combination of surfactants to produce a polyorganoalkoxysiloxane;
• b) incubating said solution, resulting in a three-dimensional gel having a continuous, interconnected pore structure,
• c) aging the gel at a controlled pH and temperature to yield a solid monolith material, and
• d) rinsing the monolith material with an aqueous basic solution at an elevated temperature
• e) modifying the pore structure of said monolith material by hydrothermal treatment,
• f) rinsing the monolith material with water followed by a solvent exchange, and
• g) drying the monolith material at room temperature drying and at an elevated temperature under vacuum.

A porous inorganic/organic hybrid monolith material comprising coalesced porous hybrid particles of hybrid silica having a chromatographically-enhancing pore geometry and a formula SiO2/[C2H4(SiO1 5)2]0 25 produced by the process of

• a) prepolymerizing a 0.25/1.0 mole ratio mixture of bis(triethoxysilyl)ethane and tetraethoxysilane in the presence of 0.1 molar hydrochloric acid to produce a polyorganosiloxane;
• b) preparing an aqueous suspension of said polyorganoalkoxysiloxane, said suspension further comprising the surfactant Triton X-100, and gelling said suspension in the presence of a ammonium hydroxide so as to produce porous hybrid parties;
• c) modifying the pore structure of said porous hybrid particles by hydrothermal treatment at 155° C. for 20 h in 0.3 M tris(hydroxymethyl)aminomethane, pH adjusted to 9.80;
• d) sizing to a nominal 2 μm particle diameter;
• e) acid washing in a 1 molar hydrochloric acid solution;
• f) further surface modifying with octadecyltrichlorosilane wherein any free silanol groups remaining from said surface modification are endcapped with chlorotrimethylsilane;
• and
• g) coalescing said porous hybrid particles to form a monolith material.

A porous inorganic/organic hybrid monolith material having a chromatographically-enhancing pore geometry and a formula SiO2/[CH3SiO1 5]0 5, produced by the process of

• a) preparing an aqueous solution of methyltrimethoxysilane and a tetramethoxysilane in the presence of a 0.07 molar acetic acid solution and the surfactant Pluronic P-105 or Trition X-100 to produce a polyorganoalkoxysiloxane;
• a) incubating said solution for 3 days at 45° C., resulting in a three-dimensional gel having a continuous, interconnected pore structure;
• b) aging the gel in 1 molar ammonium hydroxide at 60° C. for 3 days to yield a solid monolith material;
• c) rinsing the monolith material with water;
• d) modifying the pore structure of said monolith material by hydrothermal treatment at155° C. for 20 h in 0.1 molar tris(hydroxymethyl)aminomethane, pH adjusted to 8.0;
• e) rinsing the monolith material with water followed by a solvent exchange;
• f) acid washing the monolith material in 1 molar hydrochloric acid for 24 hours at 98° C.;
• g) rinsing the monolith material with water followed by a solvent exchange;
• h) drying the monolith material at room temperature drying and at 80° C. under vacuum;
• and
• i) further surface modifying with octadecyltrichlorosilane wherein any free silanol groups remaining from said surface modification are endcapped with chlorotrimethylsilane.

A porous inorganic/organic hybrid monolith material having a chromatographically-enhancing pore geometry and a formula SiO2/[C2H4(SiO1.5)2]0 25, produced by the process of

• a) preparing an aqueous solution 1,2-bis(trimethoxysilyl)ethane and tetramethoxysilane in the presence of a 0.09 molar acetic acid solution and the surfactant Pluronic P-123 to produce a polyorganoalkoxysiloxane;
• b) incubating said solution for 2 days at 45° C., resulting in a three-dimensional gel having a continuous, interconnected pore structure;
• c) aging the gel in 1 molar ammonium hydroxide at 60° C. for 2 days to yield a solid monolith material;
• d) rinsing the monolith material with water;
• e) modifying the pore structure of said monolith material by hydrothermal treatment at 155° C. for 24 h in 0.1 M tris(hydroxymethyl)aminomethane, pH adjusted to 10.6;
• f) rinsing the monolith material with water followed by a solvent exchange;
• g) acid washing the monolith material in 1 molar hydrochloric acid for 24 hours at 98° C.;
• h) rinsing the monolith material with water followed by a solvent exchange;
• i) drying the monolith material at room temperature drying and at 80° C. under vacuum, and
• j) further surface modifying with octadecyltrichlorosilane wherein any free silanol groups remaining from said surface modification are endcapped with chlorotrimethylsilane.

A porous inorganic/organic hybrid monolith material having a chromatographically-enhancing pore geometry and a formula SiO2/[HOC3H6SiO1.5]0 15, produced by the process of

• a) preparing an aqueous solution methacryloxypropyltrimethoxysilane and tetramethoxysilane in the presence of a 0.015 molar acetic acid solution and the surfactant Triton X-100 or Triton 405 to produce a polyorganoalkoxysiloxane;
• b) incubating said solution for 3 days at 45° C., resulting in a three-dimensional gel having a continuous, interconnected pore structure;
• c) aging the gel in 1 molar ammonium hydroxide at 60° C. for 3 days to yield a solid monolith material;
• d) rinsing the monolith material with water;
• e) modifying the pore structure of said monolith material by hydrothermal treatment at 155° C. for 24 h in 0.1 M tris(hydroxymethyl)aminomethane, pH adjusted to 10.6;
• f) rinsing the monolith material with water followed by a solvent exchange;
• g) acid washing the monolith material in 1 molar hydrochloric acid for 24 hours at 98° C.;
• h) rinsing the monolith material with water followed by a solvent exchange;
• i) drying the monolith material at room temperature drying and at 80° C. under vacuum, and
• j) further surface modifying with dodecylisocyanate.