SUPERFICIALLY POROUS MATERIALS COMPRISING A COATED CORE HAVING NARROW PARTICLE SIZE DISTRIBUTION; PROCESS FOR THE PREPARATION THEREOF; AND USE THEREOF FOR CHROMATOGRAPHIC SEPARATIONS
The present invention provides novel chromatographic materials, e.g., for chromatographic separations, processes for its preparation and separations devices containing the chromatographic material; separations devices, chromatographic columns and kits comprising the same; and methods for the preparation thereof. The chromatographic materials of the invention are chromatographic materials comprising having a narrow particle size distribution.
1 . A superficially porous material comprising:
a substantially nonporous core material comprising a silica core;
a substantially nonporous core coating material disposed on the surface of the substantially nonporous core, wherein the substantially nonporous core coating material comprises a metal oxide; and
one or more layers of a porous shell material disposed on the substantially nonporous core coating material.
2 . The superficially porous material of claim 1 , comprising more than one layer of the porous shell material wherein each layer is independently selected from an inorganic/organic hybrid material, silica, or mixtures thereof.
3 . The superficially porous material of claim 2 , wherein the inorganic/organic hybrid material has the formula:
(SiO 2 ) d /[R 2 ((R) p (R 1 ) q SiO t ) m ] (I)
wherein,
R and R 1 are each independently C 1 -C 18 alkoxy, C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 2 -C 18 alkynyl, C 3 -C 18 cycloalkyl, C 1 -C 18 heterocycloalkyl, C 5 -C 18 aryl, C 5 -C 18 aryloxy, or C 1 -C 18 heteroaryl;
R 2 is C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 2 -C 18 alkynyl, C 3 -C 18 cycloalkyl, C 1 -C 18 heterocycloalkyl, C 5 -C 18 aryl, C 1 -C 18 heteroaryl; or absent; wherein each R 2 is attached to two or more silicon atoms;
p and q are each independently 0.0 to 3.0,
t is 0.5, 1.0, or 1.5;
d is 0 to about 30;
m is an integer from 1-20; wherein R, R 1 and R 2 are optionally substituted; provided that: (1) when R 2 is absent, m=1 and
t
=
(
4
-
(
p
+
q
)
)
2
,
when 0<p+q<3; and
(2) when R 2 is present, m=2-20 and t=(3-(p+q)), when p+q<2.
4 . The superficially porous material of claim 1 , wherein the inorganic/organic hybrid core-coating material has the formula:
(SiO 2 ) d /[(R) p (R 1 ) q SiO t ] (II)
wherein,
R and R 1 are each independently C 1 -C 18 alkoxy, C 1 -C 18 alkyl, C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 2 -C 18 alkynyl, C 3 -C 18 cycloalkyl, C 1 -C 18 heterocycloalkyl, C 5 -C 18 aryl, C 5 -C 18 aryloxy, or C 1 -C 18 heteroaryl;
d is 0 to about 30;
p and q are each independently 0.0 to 3.0, provided that when p+q=1 then t=1.5; when p+q=2 then t=1; or when p+q=3 then t=0.5.
5 . The superficially porous material of claim 1 , wherein the inorganic/organic hybrid core-coating material has the formula:
(SiO 2 ) d /[(R 2 ((R 1 ) r SiO t ) m ] (III)
wherein,
R 1 is C 1 -C 18 alkoxy, C 1 -C 18 alkyl, C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 2 -C 18 alkynyl, C 3 -C 18 cycloalkyl, C 1 -C 18 heterocycloalkyl, C 5 -C 18 aryl, C 5 -C 18 aryloxy, or C 1 -C 18 heteroaryl;
R 2 is C 1 -C 18 alkyl, C 2 -C 18 alkenyl, C 2 -C 18 alkynyl, C 3 -C 18 cycloalkyl, C 1 -C 18 heterocycloalkyl, C 5 -C 18 aryl, C 1 -C 18 heteroaryl; or absent; wherein each R 2 is attached to two or more silicon atoms;
d is 0 to about 30;
r is 0, 1 or 2, provided that when r=0 then t=1.5; when r=1 then t=1; or when r=2, then t=0.5; and
m is an integer from 1-20.
6 . The superficially porous material of claim 1 , having improved chemical stability to high pH mobile phases as compared to an unbonded, superficially porous silica particle of the same size.
7 . The superficially porous material of claim 1 , which has further been surface modified by:
coating with a polymer;
by coating with a polymer by a combination of organic group and silanol group modification;
a combination of organic group modification and coating with a polymer;
a combination of silanol group modification and coating with a polymer;
formation of an organic covalent bond between the material's organic group and a modifying reagent; or
a combination of organic group modification, silanol group modification and coating with a polymer.
8 . The superficially porous material of claim 1 , wherein the substantially nonporous core coating material is derived from condensation of one or more polymeric organofunctional metal precursors and/or polymeric metal oxide precursors on a surface of the silica core, or
application of partially condensed polymeric organofunctional metal precursors, a mixture of two or more polymeric organofunctional metal precursors, or a mixture of one or more polymeric organofunctional metal precursors with a polymeric metal oxide precursor on the surface of the silica core.
9 . The superficially porous material of claim 1 , comprising more than one layer of porous shell material, wherein each layer of the porous shell material is applied using a polyelectrolyte or a chemically degradable polymer.
10 . The superficially porous material of claim 1 wherein the initial superficially porous particle contains>90 molar % silica.
11 . The superficially porous material of claim 1 , wherein the one or more layers of the porous shell material are porous silica.
12 . The superficially porous material of claim 1 , wherein the one or more layers of the porous shell material are formed in a layer-by-layer process using alternating additions of polyelectrolyte and silica sol.
13 . The superficially porous material of claim 1 , wherein each of the one or more layers of the porous shell material is independently from 0.05 μm to 5 μm in thickness as measured perpendicular to a surface of the substantially nonporous core material.
14 . The superficially porous material of claim 1 , wherein each of the one or more layers of the porous shell material is independently from 0.06 μm to 1 μm in thickness as measured perpendicular to a surface of the substantially nonporous core material.