POLYAMIDE MEMBRANES VIA INTERFACIAL POLYMERSATION WITH MONOMERS COMPRISING
A PROTECTED AMINE GROUP
5 FIELD
[0001] The present disclosure relates to polymeric matrices composed of
protected amine compound residues and membranes made from such polymeric
matrices.
BACKGROUND
10 [0002] Membranes for use in reverse osmosis or nano-filtration are
generally fabricated by interfacial polymerization of a monomer in a non-polar
(e.g. organic) phase together with a monomer in a polar (e.g. aqueous) phase on
a porous support membrane and are used, for example, in the purification of
water. Such membranes are subject to fouling resulting in reduced flux as
15 contaminants, for example from the water to be purified, build up on the surface
of the membrane.
[0003] The general strategy for improving membrane performance has
focused on i) addition of non-reactive solvent additives in organic or aqueous
phases during interfacial polymerization, ii) post rinsing and treatment of the as
20 made membrane after fabrication of barrier layer, and iii) addition of swelling
agents after rinsing and prior to drying of the polymer membrane.
[0004] Various characterizations of membranes show that the structure of
the polyamide barrier layer in thin-film composite (TFC) membranes is important
to its performance and application. The polyamide layer of many TFC-
25 membranes fabricated by interfacial polymerization of monomer units shows
ridge-and-valley surface morphology and two distinct loose domains (carboxyl-
rich and carboxyl-free) separated by a thin dense interlayer. Because the
carboxyl-rich domain is on the top of the membrane, it introduces a negative
charge on the membrane surface during normal operation conditions, which is amajor factor that contributes to membrane fouling and flux decrease during
operation.
SUMMARY
[0005] The present disclosure relates to a polymeric matrix, useful in
membrane technology, such as in reverse osmosis or nano-filtration membranes,
which has a reduced amount of negative charge on the top surface of the
membrane, and therefore, has a lower potential for membrane fouling. The
incorporation of hyperbranched polyamide structures into the polymeric matrix
via the interfacial polymerization process using a monomer unit comprising a
protected amino group in the organic phase, results in a decrease in the amount
of free carboxyl groups that form on the top surface of the matrix during the
polymerization of a polyamine and an amine reactive polyacyl compound. In
addition, the incorporation of monomer additives comprising a protected amino
group into the polyamide polymeric matrix results in the in situ formation of nano-
sized structures. When the polymeric matrix is supported by a substrate to form
a membrane (for example, a RO or NF membrane), the in situ formed nano-
structures increase the flux (A value) of the membranes.
[0006] Accordingly, the present disclosure relates to a polymeric matrix,
wherein the matrix is composed of:
(i) amine compound residues having at least two amine moieties;
(ii) acyl compound residues having at least two acyl moieties; and
(iii) protected amine compound residues having
(a) at least two amine moieties, or
(b) at least one amine moiety and at least one acyl moiety.
[0007] In another embodiment, at least a portion of the protected amine
compound residues comprising at least one amine moiety and at least one acyl
moiety comprise a self-polymerized polymer[0008] In another embodiment, the polymeric matrix further comprises a
substrate to form a membrane, and the membrane possesses an A value of least
about 5.0.
[0009] The present disclosure relates to a polymeric matrix comprising a
polyamide polymer, wherein the polymer is formed from:
(i) polyamine monomers;
(ii) amine reactive polyacyl monomers; and
(iii) monomers comprising a protected amino group.
[0010] The disclosure also relates to a polymeric reaction product formed
from interfacial polymerization of:
(i) polyamine monomers;
(ii) amine reactive polyacyl monomers; and
(iii) monomers comprising a protected amino group.
[0011] The present disclosure also includes a process for preparing
membranes comprising a polymeric matrix of the disclosure which reduce the
surface negative charge of the membrane. Accordingly, in one embodiment,
included in the disclosure is an interfacial polymerization process to prepare a
membrane, comprising:
contacting a substrate with:
an aqueous solution comprising
(i) polyamine monomers; and
an organic solution comprising
(i) amine reactive polyacyl monomers; and
(ii) monomers comprising a protected amino group.
[0012] The membranes comprising the polymeric matrices of the present
disclosure are useful as reverse osmosis or nano-filtration membranes for the
treatment of water, for example seawater, brackish water, or wastewater, to
reduce the concentration of solutes (such as salt) in the water.[0013] Other features and advantages of the present disclosure will
become apparent from the following detailed description. I t should be
understood, however, that the detailed description and the specific examples
while indicating preferred embodiments of the disclosure are given by way of
illustration only, since various changes and modifications within the spirit and
scope of the disclosure will become apparent to those skilled in the art from this
detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
[0014] Embodiments of the disclosure will be described in relation to the
drawings in which:
[0015] Figure 1 is a graph illustrating the passage of sodium chloride
through a membrane vs. the A value of a membrane representing an
embodiment of the disclosure using monomers comprising a protected amino
group.
DETAILED DESCRIPTION
(I) DEFINITIONS
[0016] Unless otherwise indicated, the definitions and embodiments
described in this and other sections are intended to be applicable to all
embodiments and aspects of the application herein described for which they are
suitable as would be understood by a person skilled in the art.
[0017] The terms "a," "an," or "the" as used herein not only include aspects
with one member, but also includes aspects with more than one member.
[0018] In embodiments comprising an "additional" or "second" component,
the second component as used herein is chemically different from the other
components or first component. A "third" component is different from the other,
first, and second components, and further enumerated or "additional"
components are similarly different.[0019] The term "matrix" means a regular, irregular and/or random
arrangement of polymer molecules. The molecules may or may not be cross-
linked. On a scale such as would be obtained from SEM, x-ray or FTNMR, the
molecular arrangement may show a physical configuration in three dimensions
like those of networks, meshes, arrays, frameworks, scaffoldings, three
dimensional nets or three dimensional entanglements of molecules. The matrix is
usually non-self supporting and most often is constructed as a coating or layer on
a support material.
[0020] The term "acyl" and "acyl moiety" refers to the functional group
"C(O)", also represented by the formula:
[0021] The term "amine" and "amine moiety" refers to a functional
grouping containing a basic nitrogen atom with a lone pair of electrons. Amines
are derivatives of ammonia (NH3) where one or more of the hydrogen atoms
have been replaced with an alkyl or aryl group. Primary amines have the
structure R'-NH2, secondary amines have the structure R'R"NH and tertiary
amines have the structure R'R"R"'N, wherein R R" and R'" are an alkyl or aryl
group.
[0022] The term "amide" refers to a chemical moiety of the formula:
[0023] The term "residues" as used herein refers to a chemical grouping
formed by the polymerization of a monomer. For example, an amine compound
residue refers to the chemical grouping formed when an amine monomer is
polymerized, an acyl compound residue refers to the chemical grouping formedwhen an polyacyl monomer is polymerized and a protected amine compound
residue refers to the chemical grouping formed when a protected amine
monomer is polymerized.
[0024] The term "protected amino group" as used herein refers to a
functional group, which upon contact with water or acid forms a primary or
secondary amino group. The monomer units containing protected amino groups
are soluble in organic solvents, such as toluene, xylene, hydrocarbons etc. For
example, in one embodiment, a protected amino group comprises the moiety -
N=S=0, and upon contact with water or acid solution forms an amino group
(-NH2) . This process is also known as a deprotection step. Accordingly, the
reaction proceeds as shown in Scheme 1.
Scheme 1
H20 or
R-N=S=0 » ► R "
2 + S0 2
H30 +
In one embodiment, a protected amino group is therefore any moiety which upon
contact with water or acidic solution forms a free amino group, which is then able
to further react in the polymerization process to prepare the polymeric matrices of
the present disclosure. In one embodiment, the monomer units comprising a
protected amino group also comprise at least one amine reactive acyl moiety,
which results in such monomer units being able to self-polymerize and form
separate polyamide polymers within the broader polymeric matrix, and which
form nano-structures and increase the A value of the polymeric matrix when used
as a membrane.
[0025] The term "Ca- -falkylene)" as used herein means straight and/or
branched chain, saturated alkylene radicals containing from "a" to "b" carbon
atoms in which one or more of the carbon atoms is optionally replaced by a
heteromoiety selected from O, S, NH and NCi -ealkyl, and includes (depending on
the identity of "a" and "b") methylene, ethylene, propylene, isopropylene, n-butylene, s-butylene, isobutylene, t-butylene, 2,2-dimethylbutylene, n-pentylene,
2-methylpentylene, 3-methylpentylene, 4-methylpentylene, n-hexylene and the
like, where the variable "a" is an integer representing the lowest number of
carbon atoms and the variable "b" is an integer representing the largest number
of carbon atoms in the alkylene radical.
[0026] The term "Ca- -(alkenylene)" as used herein means straight and/or
branched chain, saturated alkenylene radicals containing from "a" to "b" carbon
atoms and at least one double bond (for example, 1, 2, 3 or 4 double bonds), in
which one or more of the carbon atoms is optionally replaced by a heteromoiety
selected from O, S, NH and NCi-ealkyl, and includes (depending on the identity of
"a" and "b") ethenylene, propenylene, isopropenylene, n-butenylene, s-
butenylene, isobutenylene, t-butenylene, 2,2-dimethylbutenylene, n-pentenylene,
2-methylpentenylene, 3-methylpentenylene, 4-methylpentenylene, n-hexenylene
and the like, where the variable "a" is an integer representing the lowest number
of carbon atoms and the variable "b" is an integer representing the largest
number of carbon atoms in the alkenmylene radical.
[0027] The term "Ci-e-ialkyl)" as used herein means straight and/or
branched chain, saturated alkyl radicals and includes methyl, ethyl, propyl,
isopropylene, n-butyl, s-butyl, isobutyl, t-butyl, 2,2-dimethylbutyl, n-pentyl, 2-
methylpentyl, 3-methylpentyl, 4-methylpentyl, n-hexyl and the like.
[0028] The term "C2-6 -(alkenyl)" as used herein means straight and/or
branched chain, unsaturated alkyl radicals containing one or more (for example,
1, 2 or 3) double bonds and includes ethenyl, propenyl, isopropenyl, n-butenyl, s-
butenyl, isobutenyl, t-butenyl, 2,2-dimethylbutenyl, n-pentenyl, 2-methylpentenyl,
3-methylpentenyl, 4-methylpentenyl, n-hexenyl and the like.
[0029] The term "aliphatic" or "aliphatic group" is known in the art and
includes branched or unbranched carbon chains which are fully saturated (alkyl)
or which comprise one or more (e.g. 1, 2, 3, or 4) double (alkenyl) in the chain.[0030] The term "cycloaliphatic" or "cycloaliphatic group" is known in the
art and includes mono-cyclic and poly-cyclic hydrocarbons which are fully
saturated (cycloalkyl) or which comprise one or more (e.g. 1, 2, 3, or 4) double
bonds (cycloalkenyl) in the ring(s).
[0031] The term "aryl" as used herein refers to an aromatic, carbocyclic
system, e.g., of 6 to 14 carbon atoms, which can include a single ring or multiple
aromatic rings fused or linked together where at least one part of the fused or
linked rings forms the conjugated aromatic system. The aryl groups include, but
are not limited to, phenyl, naphthyl, biphenyl, anthryl, tetrahydronaphthyl,
phenanthryl, indene, benzonaphthyl, and fluorenyl.
[0032] The term "polyamine monomer" as used herein refers to any
monomer containing at least two nucleophilic primary or secondary amino
groups, which are able to react with the amine reactive polyacyl monomer units
to form a polyamide polymer, and which are soluble in an aqueous solution.
Examples of polyamine monomers include, but are not limited to, aromatic,
aliphatic and/or cycloaliphatic (or compounds containing both aromatic, aliphatic
and cycloaliphatic moieties) polyamine monomers. It will be understood by those
skilled in the art that polyamine monomer units refer to the compounds used to
prepare the polymer, while the term "amine compound residues" refers to the
compounds that have been polymerized, and which are therefore residues within
the polymeric matrix.
[0033] The terms "aliphatic polyamine monomer", "cycloaliphatic
polyamine monomer" or "aromatic polyamine monomer" as used herein refer to
an aliphatic, cycloaliphatic or aromatic monomer containing at least two
nucleophilic primary or secondary amino groups, which amino groups each react
with amine reactive polyacyl monomers to form a polyamide polymer, and which
are soluble in an aqueous solution. It will be understood by those skilled in the art
that the aliphatic or aromatic polyamine monomer units refer to the compounds
used to prepare the polymer, while the term "amine compound residues" refers tothe compounds that have already been polymerized, and which are therefore
residues within the polymeric matrix.
[0034] The term "amine reactive polyacyl monomer" as used herein refers
to a compound containing at least two reactive (electrophilic) acyl moieties of the
formula:
wherein X' is a leaving group and which are therefore able to react with
nucleophilic amine moieties to form a polyamide polymer. Examples of leaving
groups (Χ') include halogens (chloride, fluoride, bromide and iodide), anhydrides,
activated esters, and other leaving groups such as tosylates, mesylates, triflates
etc.
[0035] The terms "halogen", "halide" or "halo" as used herein include
chloro, fluoro, bromo or iodo.
[0036] The structure within the chemical structures as used herein
refers to the repeating subunits of the polymeric matrices of the disclosure, and
accordingly, further repeating monomer subunits would continue after the
structure.
[0037] The term "A value" as used herein refers to the permeate flux
capacity RO water permeability of a membrane and is represented by the cubic
centimeters of permeate water over the square centimeters of membrane area
times the seconds at the pressure measured in atmospheres.
[0038] The term "permeation" or "permeate" means transmission of a
material through a membrane.[0039] The term "membrane" when used in the context of a reverse
osmosis membrane or nano-filtration membrane as used herein refers to a
selective barrier which is used to separate dissolved components of a feed fluid
into a permeate (for example, water) that passes through the membrane and a
retentate (for examples, salts) that is rejected or retained by the membrane. It
will be understood that polymeric matrices of the present disclosure are
supported by a substrate to form the membrane, and the polymeric matrices
separate the dissolved components. The substrate is not involved in the
separation of the dissolved components.
[0040] The term "self-polymerized polymer" as used herein refers to a
polymer in which the monomelic units are able to polymerize with themselves to
form a first polymeric substructure, wherein the first polymeric substructure is
then incorporated into the broader polymer matrix (a polymeric substructure
within, or polymerized to, the broader polymeric matrix). The term "substrate"
means any substrate or support material onto which the matrix can be applied.
The substrate may be porous or non-porous.
[0041] In understanding the scope of the present disclosure, the term
"comprising" and its derivatives, as used herein, are intended to be open ended
terms that specify the presence of the stated features, elements, components,
groups, integers, and/or steps, but do not exclude the presence of other unstated
features, elements, components, groups/ integers and/or steps. The foregoing
also applies to words having similar meanings such as the terms, "including",
"having", "containing" and their derivatives. The term "consisting" and its
derivatives, as used herein, are intended to be closed terms that specify the
presence of the stated features, elements, components, groups, integers, and/or
steps, but exclude the presence of other unstated features, elements,
components, groups, integers and/or steps. The term "consisting essentially of,
as used herein, is intended to specify the presence of the stated features,
elements, components, groups, integers, and/or steps as well as those that donot materially affect the basic and novel characteristic(s) of features, elements,
components, groups, integers, and/or steps.
[0042] Terms of degree such as "substantially", "about" and
"approximately" as used herein mean a reasonable amount of deviation of the
modified term such that the end result is not significantly changed. These terms
of degree should be construed as including a deviation of at least ±5% of the
modified term i f this deviation would not negate the meaning of the word it
modifies.
(II) MATRICES AND MEMBRANES
[0043] The present disclosure relates to a polymeric matrix, useful in a
membrane (such as a reverse osmosis membrane or nano-filtration membrane)
which has a reduced amount of negative charge on its top surface. Therefore, a
membrane of the disclosure has a lower potential for membrane fouling. The
incorporation of monomelic units which comprise a protected amino group in the
organic phase during an interfacial polymerization process between a polyamine
monomer and an amine reactive polyacyl monomer, results in a decrease in the
amount of free carboxyl groups that form on the top surface of a membrane
comprising the matrix. The matrices of the disclosure also possess balanced
surface functionality, as well as less nanoscale heterogeneity. In addition, the
polymeric matrices of the disclosure are highly crosslinked due to the presence
of monomers which comprise a protected amino group during the polymerization
process, which results in membranes having a higher stability both to pH and
free chlorine. Finally, the membranes comprising polymeric matrices of the
disclosure have higher A values due to in situ formed nano-structures which form
as a result of the self-polymerization of the monomer units comprising protected
amine monomers.
[0044] Accordingly, the present disclosure relates to a polymeric matrix,
wherein the matrix is composed of:(i) amine compound residues having at least two amine moieties;
(ii) acyl compound residues having at least two acyl moieties; and
(iii) protected amine compound residues having
(a) at least two amine moieties, or
(b) at least one amine moiety and at least one acyl moiety.
[0045] In another embodiment, when the protected amine compound
residues contain at least one amine moiety and at least one acyl moiety, at least
a portion of the residues are formed from self-polymerization. In one
embodiment, the monomers comprising a protected amino group which comprise
at least one amine reactive acyl moiety and at least one protected amino moiety
are able to self-polymerize once the amino group has been deprotected in the
presence of water or acid. In one embodiment, these monomers are then able to
self-polymerize into polymeric substructures (nano-sized structures which in one,
embodiment, increase the flux of a membrane containing such structures), which
are subsequently incorporated into the broader polymeric matrix (formed from
polyamine monomers and amine reactive polyacyl monomers, and/or the
monomers comprising a protected amino group) during, for example, an
interfacial polymerization process.
[0046] In another embodiment, the polymeric matrix further comprises a
substrate to form a membrane, and the membrane possesses an A value greater
than zero, optionally at least about 5.0.
[0047] In another embodiment, the protected amino compound residue is
a residue of the formula (I):
)n (I),
wherein
Ar is an optionally substituted aryl group containing 6-14 carbon atoms;R is independently or simultaneously , and
n is 1, 2 or 3,
wherein the optional substituents comprise from one to five of halo, (CrC 6)-alkyl,
(Ci-C 6)-alkenyl, or (Ci-C )-alkynyl.
[0048] In another embodiment, Ar is an optionally substituted aryl group
containing 6-10 carbon atoms, for example phenyl or naphthyl. In another
embodiment, Ar is an optionally substituted Ce-aryl group, for example, phenyl.
In another embodiment, the optional substituents comprise methyl, ethyl, propyl
or iso-propyl.
[0049] In another embodiment, the residues of the formula (I) are residues
of the formula (la), (lb) or (lc):
wherein R i
[0050] In one embodiment, the residue of the formula (la) is:[0051] In another embodiment, the residue of the formula (lb) is:
[0053] In another embodiment, the residue of the formula (lc) is:
[0054] In another embodiment, the amine compound residues comprises
at least two amino (-NH) moieties. In an embodiment, the amine compound
residues comprise an aliphatic amine compound residue, an aromatic amine
compound residue or a cycloaliphatic amine compound residue. In a furtherembodiment, the aromatic amine compound residue comprises a residue of the
formula (II):
wherein Ar is an optionally substituted aryl group containing 6-14 carbon atoms;
and
p is 2 or 3,
wherein the optional substituents comprise from one to five of halo, (C -C -alkyl ,
(Ci-Ce)-alkenyl, or (C -C )-alkynyl.
[0055] In another embodiment, Ar is an optionally substituted aryl group
containing 6-10 carbon atoms, for example phenyl or naphthyl. In another
embodiment, Ar is an optionally substituted C -aryl group, for example, phenyl.
In another embodiment, the optional substituents comprise methyl, ethyl, propyl
or iso-propyl.
[0056] In another embodiment, the aromatic polyamine residue of the
formula (II) is
[0057] In another embodiment, the aromatic polyamine residue of formula
(II) is:
[0058] In another embodiment of the disclosure, the cycloaliphatic amine
compound residue is a residue of the formula (III):wherein q is 0, , 2, 3 or 4,
and wherein at least two of the carbon atoms are replaced by N atoms that
participate in bonding with the polymer matrix.
[0059] In another embodiment, the cycloaliphatic amine compound residue
is a C5-C7-cycloaliphatic, wherein at least two of the carbon atoms are replaced
by N atoms that participate in bonding with the polymer matrix. In another
embodiment, the cycloaliphatic amine compound residue is a C 6-cycloaliphatic,
wherein at least two of the carbon atoms are replaced by N atoms that participate
in bonding with the polymer matrix.
[0060] In another embodiment, the cycloaliphatic amine compound residue
of formula III is:
[0061] In one embodiment of the disclosure, the aliphatic amine compound
residues are derived from monomers comprising at least two free amino (-NH 2)
moieties. In another embodiment, the aliphatic amine compound residue is a
residue of the formula (IV):
wherein W is a (C2-
2o)-alkylene group or a (C2-2o)-alkenylene group, and wherein
at least one carbon atom, optionally at least two carbon atoms, in the alkylene or
alkenylene group is optionally replaced by O, S, NH or N(Ci-6)alkyl moieties,
suitably NH or N(d-6)alkyl moieties. In another embodiment, W is a (C4-10)-alkylene group wherein at least one carbon atom, optionally at least two carbon
atoms, in the alkylene group is optionally replaced by NH or N(Ci -6)alkyl moieties.
In another embodiment of the disclosure, the aliphatic amine compound residue
of the formula (IV) is:
[0062] In another embodiment, the acyl compound residue is a residue of
the formula (V):
wherein Ar is an optionally substituted aryl group containing 6-14 carbon atoms;
and
is 2, 3 or 4,
wherein the optional substituents comprise from one to five of halo, (Ci -C6 )-alkyl,
(Ci-Ce)-alkenyl, or (Ci-Ce)-alkynyl.
[0063] In another embodiment, Ar is an optionally substituted aryl group
containing 6-10 carbon atoms, for example phenyl or naphthyl. In another
embodiment, Ar is an optionally substituted C 6-aryl group, for example, phenyl.
In another embodiment, the optional substituents comprise methyl, ethyl, propyl
or iso-propyl.
[0064] In an embodiment, the acyl compound residue of formula (V) is:wherein m is 2 or 3.
[0065] In an embodiment, the acyl compound residue of formula (V) is:
[0066] The present disclosure relates to a polymeric matrix comprising a
polyamide polymer, wherein the matrix is formed from:
(i) polyamine monomers;
(ii) amine reactive polyacyl monomers; and
(iii) monomers comprising a protected amino group.
[0067] The disclosure also includes a polymeric reaction product formed
from interfacial polymerization of:
(i) polyamine monomers;
(ii) amine reactive polyacyl monomers; and
(iii) monomers comprising a protected amino group.
[0068] In another embodiment of the disclosure, the monomer comprising
a protected amino group is a compound of the formula (VI):
Y
Ar (R)n ( I)
wherein
Ar is an optionally substituted aryl group containing 6-1 4 carbon atoms;
Y is a protected amino group;R is independently or simultaneously Y or -C(0)-X;
X is a leaving group; and
n is , 2 or 3,
wherein the optional substituents comprise from one to five of halo, (Ci-C6)-alkyl,
(Ci-C6)-alkenyl, or (Ci-C6)-alkynyl.
[0069] In another embodiment, Ar is an optionally substituted aryl group
containing 6-10 carbon atoms, for example phenyl or naphthyl. In another
embodiment, Ar is an optionally substituted C6-aryl group, for example, phenyl.
In another embodiment, the optional substituents comprise methyl, ethyl, propyl
or iso-propyl.
[0070] In another embodiment, the protected amino group (Y) is -N=S=0.
[0071] In another embodiment of the disclosure, the compound of the
formula (VI) is a compound of the formula (Via), (Vlb) or (Vic):
[0072] In an embodiment, the compound of formula (Via) is:
wherein X is a leaving group.
[0073] In another embodiment of the disclosure, the compound of the
formula (Vlb) is:wherein X is a leaving group.
[0074] In another embodiment, the compound of the formula (Vic) is:
wherein X is a leaving group.
[0075] In another embodiment of the disclosure, when one of the groups R
in the compounds of the formula (VI) is a -C(0)-X moiety, the compounds
possess dual functionality, and therefore contain a protected amino group and an
amine reactive acyl moiety. Accordingly, in one embodiment, such dual
functional monomers are able to act as amine and acyl monomers during the
preparation of the polyamide polymers and are therefore able to react in a self-
polymerization process upon contact with, for example, water or acid solution.
Once the protected amino group has been converted (deprotected) to a free
amino group, it is able to react with the amine reactive acyl moiety (-C(O)-X) of
another compound of the formula (VI). In one embodiment, such a self-
polymerization process results in the in situ formation of nano-sized structures (a
first polymeric substructure) within the broader polyamide polymeric matrix(formed from polyamine monomers, amine reactive polyacyl monomers and/or
monomers comprising protected amino groups). In one embodiment, when the
polymeric matrices of the present disclosure are supported on substrate to form a
membrane (RO or NF), the nano-sized structures formed as a result of a self-
polymerization process result in increased flux values, allowing more flow of the
liquid through the membrane. In one embodiment, such nano-sized structures,
increase the flux of a membrane, but do not affect the salt selectivity of the
membrane.
[0076] In one embodiment, the monomers comprising the protected amino
groups result in polymeric matrices having more balanced surface charges after
the interfacial polymerization (IP) process. During an IP process, water
molecules from the aqueous solution containing the polyamine monomer units
diffuses into the organic solution containing the amine reactive polyacyl monomer
units. As water is also nucleophilic, the water molecules also react with the
amjne reactive acyl moieties forming carboxylic acid groups on the top surface of
the polymeric matrices. Without being bound by theory, it is thought that the
addition of monomer units comprising protected amino groups reduces the
number of carboxylic acid groups which form as a result of the deprotection of
the protected amino moiety, such amino groups then reacting with the amine
reactive acyl moieties (rather than water). The protected amino moiety also
reacts with water molecules forming a free amino group in the organic solution,
which then is able to react with amine reactive acyl moieties, and subsequently
reducing the number of carboxylic acid groups which form during the IP process.
[0077] In another embodiment, the incorporation of monomers comprising
protected amino groups increases the crosslinking of the polyamide polymer that
is prepared using the above described monomers. In another embodiment, dual
functional monomers comprising protected amino groups and amine reactive acyl
moieties are able to react with other such dual functional monomers (self-
polymerization) to form a precursor polyamide polymer (a polymericsubstructure), which is then polymerized with the polyamine/polyacyl monomers.
For example, as shown in Scheme 2, in one embodiment, when the monomers
comprising protected amino groups are dual functional monomers (compounds of
the formula (Vld) and Vie)), the monomers react with themselves to form a
polymeric substructure (forming VII and VIII) (self-polymerization process), which
is then incorporated into the broader polyamide polymer.
Scheme 2
[0078] Accordingly, such monomer units comprising protected amino
groups form nano/hyperbranched structures in situ, and therefore increase the
porosity of the resulting membranes and the corresponding A value of the
membrane. In addition, the monomers also slow the polymerization kinetics of
the polyamide polymeric matrix formed from polyamine monomers and amine
reactive polyacyl monomers.[0079] In another embodiment of the disclosure, the monomers comprising
protected amino groups are prepared by the halogenation of unprotected
precursors (for example, an amino benzoacid), using a halogenating agent, such
as thionyl chloride or oxalyl chloride and the like. In one embodiment, the
preparation of a monomer unit comprising a protected amino group is shown in
Scheme 3. Other general reactions to form monomers comprising a protected
amino group is taught in U.S. Patent No. 5,321,162 to Kim, which is herein
incorporated by reference in its entirety. It will be understood that the
halogenations of such precursor compounds is only one example of the
preparation of such compounds, and the incorporation of any leaving group into
such precursor compounds would be within the skill of those skilled in the art.
Scheme 3
[0080] In an embodiment, when the polymeric matrices of the disclosure
are supported on substrates and used as membranes (e.g. RO or NF
membranes), the membranes possess an A value which is suitable for the
treatment of seawater and/or brackish water desalination applications under
current pressure limitations. In one embodiment, the A value is greater than 0. In
one embodiment, the A value is at least about 5.0, about 5.5 or about 6.0. In
another embodiment, as shown in Figure 1, the polymers of the disclosure
increase the A value of the membranes by at least two times (2x) (as compared
to membranes which do not contain the monomer units comprising protected
amino groups). While not wishing to be limited by theory, this effect may be a
result of the hyperbranched nanosized structures which increase (or introduce)
the porosity of the resulting polymeric matrix, and accordingly, correspondingly
increase the A value.[0081] In another embodiment, the polyamine monomer comprises at least
two reactive amino moieties. In an embodiment, the polyamine monomer
comprises an aliphatic polyamine, cycloaliphatic polyamine or aromatic
polyamine. In one embodiment, the aliphatic portion of the aliphatic polyamine
monomer is a branched or unbranched, saturated or unsaturated alkyl chain,
containing between 2 and 20 carbon atoms contains at least two primary amino
groups. Examples of such monomer units include, but are not limited to,
triethylenetetraamine, ethylenediamine, propyelendiamine, or tris(2-
aminoethyl)amine. Examples of aromatic polyamine monomers include, but are
not limited to, diaminobenzene, m-phenylenediamine, p-phenylenediamine,
triaminobenzene, ,3,5-triaminobenzene, ,3,4-triaminobenzene, 2,4-
diaminotoluene, xylylene-diamine and the like. Examples of cycloaliphatic
polyamine monomers include, but are not limited to, piperazine, imidazolidine,
diazepane and isomers and the like.
[0082] In a further embodiment, the aromatic polyamine comprises a
compound of the formula (IX):
wherein Ar is an aryl group containing 6-14 carbon atoms; and
p is 2 or 3,
wherein the optional substituents comprise from one to five of halo, (Ci-Ce>-alkyl,
(Ci-C 6)-alkenyl, or (C Ce)-alkynyl.
[0083] In another embodiment, Ar is an optionally substituted aryl group
containing 6-10 carbon atoms, for example phenyl or naphthyl. In another
embodiment, Ar is an optionally substituted Craryl group, for example, phenyl.
In another embodiment, the optional substituents comprise methyl, ethyl, propyl
or iso-propyl.In another embodiment, the aromatic polyamine of the formula (IX)
[0085] In another embodiment, the aromatic polyamine of the formula (IX)
is
[0086] In another embodiment of the disclosure, the cycloaliphatic
polyamine monomer is a monomer of the formula (X):
wherein q is 1, 2, 3 or 4,
and at least two of the carbon atoms are replaced with -NH,
wherein the cycloaliphatic ring is optionally substituted by one to five of halo, (C
C )-alkyl, ( -C )-alkenyl, or (Ci-C 6)-alkynyl.
[0087] In another embodiment, the cycloaliphatic polyamine monomer is a
Cs-Crcycloaliphatic ring, wherein at least two of the carbon atoms are replaced
with -NH. In another embodiment, the cycloaliphatic polyamine monomer is a Ce-
cycloaliphatic ring, wherein at least two of the carbon atoms are replaced with -
NH.
[0088] In another embodiment, the cycloaliphatic polyamine monomer of
formula X is:[0089] In another embodiment of the disclosure, the aliphatic polyamine
monomer comprises at least two reactive amino (-NH2) moieties. In another
embodiment, the aliphatic polyamine monomer is a compound of the formula
(XI):
w
X |
wherein W is a (C2-2o)-alkylene group or a (C2-2o)-alkenylene group, and wherein
at least one carbon atom, optionally at least two carbon atoms, in the alkylene or
alkenylene group is optionally replaced by O, S, N H or N(Ci-6 )alkyl moieties,
suitably N H or N(Ci-6 )alkyl moieties. In another embodiment, W is a (C4-10)-
alkylene group wherein at least one carbon atom, optionally at least two carbon
atoms, in the alkylene group is optionally replaced by N H or N(Ci-6 )alkyl moieties.
In an embodiment, the aliphatic polyamine monomer is, triethylenetetraamine,
ethylenediamine, propylenediamine, or tris(2-aminoethyl)amine. In another
embodiment of the disclosure, the monomer of the formula (XI) is:
[0090] In another embodiment of the disclosure, the amine reactive
polyacyl monomer is a compound of the formula (XII):
wherein m is 2, 3 or 4 ;
Ar is an optionally substituted aryl group containing 6-14 carbon atoms; andX' is a leaving group, wherein the optional substituents comprise from one to five
of halo, (CrC 6)-alkyl, (Ci-Ce)-alkenyl, or (CrCe)-alkynyl. Examples of amine
reactive polyacyl monomers include, but are not limited to, aromatic acyl halides
such as trimesoyi halide, trimellitic halide, isophthaloyt halide, terephthaloyi
halide, and the like.
[0091] In another embodiment, Ar is an optionally substituted aryl group
containing 6-10 carbon atoms, for example phenyl or naphthyl. In another
embodiment, Ar is an optionally substituted Ce-aryl group, for example, phenyl.
In another embodiment, the optional substituents comprise methyl, ethyl, propyl
or iso-propyl.
[0092] In another embodiment, the amine reactive polyacyl monomer of
formula (XII) is:
wherein m is 2 or 3; and
X' is a leaving group.
[0093] In another embodiment, the amine reactive polyacyl monomer of
formula (XII) is:
wherein X' is a leaving group.[0100] In another embodiment, the leaving group X' is halogen, such as
chloro, bromo, iodo or fluoro. In one embodiment, the leaving group, X", is
chloro.
[0094] In one embodiment, membranes comprising polymers of the
present disclosure are useful for the treatment of water, for example, the
desalination of seawater. Accordingly, the disclosure includes methods of
treating water, such as seawater, comprising filtering the water with the RO or NF
membrane as described above to remove ions such as sodium, magnesium,
calcium, potassium, chloride, sulphate, etc. In one embodiment, the membranes
are used in applications such as water purification devices and selective
separation systems for aqueous and organic liquids carrying dissolved or
suspended components.
(Ill) PROCESSES, DEVICES AND USES
[0095] The present disclosure also includes an interfacial polymerization
(IP) process for preparing the polymeric matrices of the disclosure, which
matrixes provide a membrane having a reduced surface negative charge and
increased A value. IP processes generally proceed through the contact of an
aqueous solution comprising polyamine monomerss and an organic solution
comprising amine reactive polyacyl monomers. At the interface of the two
solutions (aqueous and organic solutions), the monomer units comprising
protected amino groups are deprotected by interaction with water to form free
amino monomers that react with existing matrix to form a modified polyamide
polymer. In prior polyamide matrices prepared by IP, excess free carboxyl
groups are formed on the surface of the polymer during or after the IP process as
a result of water (from the aqueous solution) reacting with the residual amine
reactive polyacyl monomers. In the present disclosure, it is one embodiment
that, as a result of the addition of the monomers comprising a protected amino
group in the organic solution, there is a reduction in the amount of free carboxyl
groups (and therefore surface negative charge) which are formed during the IPprocess due to the interaction between deprotected amino groups from monomer
units and residual amine reactive polyacyl monomers.
[0096] Accordingly, in one embodiment of the disclosure, there is included,
an interfacial polymerization process to prepare a membrane comprising a
polyamide polymeric matrix, the method comprising:
contacting a substrate with:
an aqueous solution comprising
(i) polyamine monomers; and
an organic solution comprising
(i) amine reactive polyacyl monomers; and
(ii) monomers comprising a protected amino group,
wherein the polyamine monomers, amine reactive polyacyl monomers and the
monomers comprising a protected amino group are as defined above.
[0097] In one embodiment, the substrate is first contacted with the
aqueous solution and subsequently with the organic solution, or in another
embodiment, the substrate is first contacted with the organic solution and then
subsequently with the aqueous solution.
[0098] In another embodiment of the disclosure, the process is conducted
in the presence of a non-nucleophilic base, such as, but not limited to, 4-
dimethylaminopyridine (D AP) or pyridine.
[0099] In another embodiment, the polyamine monomers are present in
the aqueous solution in an amount between 1-4% (wt/wt), 1.5-2.5% (wt/wt) or
about 2.0% (wt/wt). In another embodiment, the amine reactive polyacyl
monomers are present in the organic solution in an amount between 0.01-0.5%
(wt/wt), about 0.10-0.30% (wt/wt) or about 0.20% (wt/wt). In a further
embodiment, the monomers comprising a protected amino group are present in
the organic solution in an amount between 0.01-0.20%(wt/wt), about 0.03-0.10%
(wt/wt) or about 0.03-0.06% (wt/wt).[00100] The membrane may be further processed to remove residual
chemicals, adjust performance, and/or to apply a protective coating. For
example, post formation treatment with chlorinating agents, amine methylating
agents, oxidizing agents and the like may provide performance improvements.
After such optional treatment, the membrane is ready for use. The membrane
may also be stored for later use.
[00101] The polymer matrices of the present disclosure may be formed into
the composite membranes of the present disclosure and incorporated into
filtration, separation, concentration apparatuses as well as medical devices,
blood treatment devices and the like. These devices are also useful for water
purification, for desalination, for industrial waste treatment, for minerals recovery
such as from the mining industry, and for recovery of application solids from
industrial processing. Further uses include layers or coatings upon the surface of
any substrate including but not limited to a porous bead, a chromatographic
material, a metal surfaces, a microdevice, a medical device, a catheter and the
like. These coatings may act as lubricants, antibiotics, reservoirs, and/or filters for
agents passed over the coated substrate. The coatings may also carry biological
agents (e.g. antibodies, antibiotics, anti blood plasma coagulants, nucleotides,
pharmaceuticals, and the like). The matrix may also be used to encapsulate and
also to allow controlled release of pharmaceutical agents, diagnostic agents,
cosmetics, and the like.
[00102] In an embodiment, the polymeric matrices of the present disclosure
are useful in membrane technology for the treatment of water, for example, the
desalination of seawater. Accordingly, the disclosure includes methods of
treating water, such as seawater, comprising filtering the water with a membrane
(such as an RO or NF membrane) comprising a polymeric matrix of the present
disclosure supported on a substrate to remove ions such as sodium, magnesium,
calcium, potassium, chloride, sulfate, etc. In another embodiment, membranes
using the matrices of the present disclosure are also useful in water purificationdevices and selective separation systems for aqueous and organic liquids
carrying dissolved or suspended components.
[00103] The disclosure also includes methods of treating water, for example
the desalination of seawater, comprising passing the water through a membrane
comprising a polymeric matrix of the disclosure in a reverse osmosis or nano-
filtration process.
[00104] The composite membranes of the present disclosure can be used
in any configuration or arrangement to achieve separation of solute from solvent.
These configurations include partition, absolute filtration, chromatography,
exchange and pass through concentration as well as other configurations known
in the art. Although dead end filtration and chromatography configurations can be
used with the composite membranes of the present invention, cross-flow filtration
is optimal. Dead-end configurations call for passage of all solvent through the
composite membrane and retention of solute at the filtration side of the
composite membranes. The buildup of solute at the membrane surface may
cause caking. In these configurations, the filtration apparatus must be
periodically back flushed in order to remove cake solids or the filter discarded.
Cross-flow configurations involve partial pass through of the feed liquid such that
rejected solute is continually flushed away from the filtering membrane surface
and passed with the retentate.
[00105] The following non-limiting examples are illustrative of the present
disclosure:
EXAMPLES
[00106] The disclosure will now be described in further details by way of the
following examples, wherein the temperatures are indicated in degrees
centigrade and the abbreviations have the usual meaning in the art.Experimental
[00107] Two parts by weight of m-phenylenediamine (MPD) and 6.6 parts
by weight of camphorsulfonic acid/triethylamine salt, and 91.4 parts by weight
water were mixed together to prepare an aqueous solution. This aqueous
solution was applied to a typical porous supporting film (polysulfone on PET
faber). The excess aqueous solution was removed to form a film the porous
supporting film. An isopar-G solution containing about 0.2% by weight trimesoyl
chloride (TMC) or a total of about 0.2% by weight of mixed monomers (TMC +
protected amine monomers) was applied to the film. The excess isopar-G
solution was removed, and this supporting film was held in 60°C, drying oven for
6 minutes to form a thin film on the porous supporting film. Thus a composite
semipermeable RO membrane was obtained.
[00108] The composite semipermeable RO membrane produced was used
to contact a permeation test in which 2000 ppm aqueous sodium chloride
solution was treated as a raw water under the conditions of a temperature of
25C, pH of 6.5 and pressure of 225 psi. As a result, the sodium chloride solution
rejection and permeation flux (represented as A value) was obtained, as seen in
Tables 1 and 2, and Figure 1.
[00109] While the present disclosure has been described with reference to
what are presently considered to be the preferred examples, it is to be
understood that the disclosure is not limited to the disclosed examples. To the
contrary, the disclosure is intended to cover various modifications and equivalent
arrangements included within the spirit and scope of the appended claims.
[00110] All publications, patents and patent applications are herein
incorporated by reference in their entirety to the same extent as i f each individual
publication, patent or patent application was specifically and individually indicated
to be incorporated by reference in its entirety. Where a term in the present
application is found to be defined differently in a document incorporated hereinby reference, the definition provided herein is to serve as the definition for the
term.Table 1: Fabrication of Membranes using Protected Amino Groups (VId)Table 2: Fabrication of Membranes using Protected Amino Groups (Vie)WE CLAIM:
1. A polymeric matrix, wherein the matrix is composed of:
(i) amine compound residues having at least two amine moieties;
(ii) acyl compound residues having at least two acyl moieties; and
(iii) protected amine compound residues having
(a) at least two amine moieties, or
(b) at least one amine moiety and at least one acyl moiety.
2. The matrix of claim , wherein at least a portion of the protected amine
compound residues comprising at least one amine moiety and at least one acyl
moiety comprise a self-polymerized polymer.
3. The matrix of claim 1, further comprising a substrate to form a membrane
and wherein the membrane possesses an A value of at least about 5.0.
4. The matrix of claim 1, wherein the protected amino compound residue is a
residue of the formula (I):
HN-—
Ar (R)
wherein
Ar is an aryl group containing 6-14 carbon atoms;
R is independently or simultaneously , and
n is 1, 2 or 3 .
5. The matrix of claim 4, wherein the residues of the formula (I) are residues
of the formula (la), (lb) or (lc):7. The matrix of aim 5, wherein the residue of the formula (lb) is:9. The matrix of claim 1, wherein the amine compound residues comprise an
aromatic amine compound residue, an aliphatic amine compound residue, or a
cycloaliphatic amine compound residue.
10. The matrix of claim 9, wherein the aromatic amine compound residue
comprises a residue of the formula II):
wherein Ar is an aryl group containing 6- carbon atoms; and
wherein p is 1, 2 or 3.
1. The matrix of claim 10, wherein the residue of the formula (II) is:
12. The matrix of claim 1, wherein the acyl compound residue is a residue of
the formula (III):
wherein
Ar is an aryl group containing 6-14 carbon atoms;
m is 2, 3 or 4.
The matrix of claim 12, wherein the residue of formula (III) is:wherein m is 2 or 3.
The matrix of claim 13, wherein the residue of formula (III) is:
A polymeric reaction product formed from interfacial polymerization of:
(i) polyamine monomers;
(ii) amine reactive polyacyl monomers; and
(iii) monomers comprising a protected amino group.
16. The polymeric reaction product of claim 15, wherein the monomers
comprising a protected amino group are compounds of the formula (VI):
Y
Ar ( )n i)
wherein
Ar is an aryl group containing 6-14 carbon atoms;
Y is a protected amino group;
R is independently or simultaneously Y or -C(0)-X;
X is a leaving group; andn is 1, 2 or 3.
The polymeric reaction product of claim 16, wherein Y is -N=S=0.
18. The polymeric reaction product of claim 16, wherein the compound of the
formula (VI) is a compound of the (Via), (Vlb) or (Vic):
(Via), (Vlb) or (Vic),
wherein R is independently or simultaneously N=S=0 or -C(0)-X; and
X is a leaving group.
19. The polymeric reaction product of claim 18, wherein the compound of the
formula (Via) is:
wherein X is a leaving group.
20. The polymeric reaction product of claim 18, wherein the compound of the
formula (Vlb) is:wherein X is a leaving group.
2 1. The polymeric reaction product of claim 18, wherein the compound of the
formula (Vic) is:
wherein X is a leaving group.
22. The polymeric reaction product of claim 16, wherein leaving group is a
halogen atom.
23. The polymeric reaction product of claim 15, wherein the polyami
monomers comprise at least two reactive amino (-NH2) moieties.
24. The polymeric reaction product of claim 23, wherein the polyamine
monomers comprise aromatic polyamine monomers, aliphatic polyamine
monomers or cycloaliphatic polyamine monomers.25. The polymeric reaction product of claim 24, wherein the aromatic
polyamine monomers are compounds of the formula (IX)
wherein Ar is an aryl group containing 6-14 carbon atoms; and
p is 1, 2 or 3.
26. The polymeric reaction product of claim 25, wherein the aromatic
polyamine monomer is:
27. The polymeric reaction product of claim 15, wherein the amine reactive
polyacyl monomers are compounds of the formula (XII):
wherein
Ar is an aryl group containing 6-14 carbon atoms;
X is a leaving group;
m is 2, 3 or 4.
28. The polymeric reaction product of claim 27, wherein the amine reactive
polyacyl monomer of the formula (XII) is:wherein m is 2 or 3 ; and
X" is a leaving group.
29. The polymeric reaction product of claim 28, wherein the amine reactive
polyacyl monomers is:
wherein X" is a leaving group.
30. The polymeric reaction product of claim 29, wherein X' is a halogen atom.
3 1. An interfacial polymerization process to prepare a membrane comprising a
polymeric matrix as defined in claim 1, comprising:
contacting a substrate with:
an aqueous solution comprising
(i) polyamine monomers; and
an organic solution comprising
(i) amine reactive polyacyl monomers; and
(ii) monomers comprising a protected amino group.32. The process of claim 3 , wherein the substrate is first contacted with the
aqueous solution and then subsequently contacted with the organic solution.
33. The process of claim 3 1, wherein the substrate is first contacted with the
organic solution and then subsequently contacted with the aqueous solution.
34. The process as claimed in claim 3 1, wherein the polyamine monomers are
present in the aqueous solution in an amount between 1-4% (wt/wt).
35. The process as claimed in claim 3 1, wherein the amine reactive polyacyl
monomers are present in the organic solution in an amount between 0.01-0.5%
(wt/wt).
36. The process as claimed in claim 3 , wherein the monomers comprising a
protected amino group are present in the organic solution in an amount between
0.01-0.50% (wt/wt).
37. A combination comprising the polymeric matrix of claim 1 coated on a
support material.
38. A composite membrane comprising a polymeric matrix according to claim
1 on a porous support material.
39. The composite membrane of claim 38 that is a reverse osmosis (RO) or
nano-filtration (NF) membrane.