Synthetic resins or natural rubbers -- part of the class 520 ser – Synthetic resins – Compositions to be polymerized by wave energy wherein said...
Reexamination Certificate
2000-08-18
2002-09-03
Seidleck, James J. (Department: 1711)
Synthetic resins or natural rubbers -- part of the class 520 ser
Synthetic resins
Compositions to be polymerized by wave energy wherein said...
C522S173000, C522S178000, C522S182000, C522S085000, C522S084000, C522S086000, C522S186000, C524S458000, C524S815000, C524S291000, C524S460000, C526S333000
Reexamination Certificate
active
06444723
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to materials used for separating and concentrating solutes and, more particularly, to micellar materials for used for carrying out separating and concentrating functions.
2. Description of the Prior Art
One approach to the separation and concentration of solutes from solvents involves the employment of surfactants. Surfactants are two-part molecules with one part hydrophilic (the “head”, often charged) and the other part hydrophobic (the “tail”, typically a hydrocarbon). In aqueous solution, surfactants aggregate into structures called micelles wherein the hydrophobic tails cluster together, and expose only their hydrophilic heads to the aqueous solution. These micelles are comprised of approximately 100 individual surfactant molecules that form a dynamic micellar aggregate with a typical diameter of 5 nm. The micelles are often colloidal in nature.
Oily or hydrophobic materials are readily solubilized in the hydrophobic core of the-surfactant micelles. The hydrophobic core provides an energetically favorable environment for solubilizing the oily molecules. In contrast, the hydrophilic head, water, and other polar solvents have unfavorable interaction energies with hydrophobic materials. Since the micelle is not a covalently bonded structure, the individual molecules are free to move, so that large quantities of hydrophobic solutes (with substantially no size restrictions on the individual solutes) can be accommodated by the hydrophobic core.
Some of the difficulties presented by surfactant micelles are their small size (5 nm) and their dynamic character. Due to their extremely small size and their colloidal nature, the micelles and material solubilized therein cannot be removed easily from solution by sedimentation, filtration, or any other comparable physical separation methods. In view of the problems associated with the small size of surfactant micelles, it would be desirable if a micellar material were provided that has macroscopic dimensions.
Their dynamic character also presents problems. The stability (and solubilization capacity) of a surfactant aggregate is highly sensitive to its chemical and physical environment. Slight changes in temperature, salt concentration, or solvent composition can instantly dissolve the aggregates and release their solubilized material. Despite these limitations, the surfactant industry is still a multi-billion dollar/year industry. In view of the problems associated with the dynamic character of surfactant micelles, it would be desirable if a micellar material were provided that has stable micellar properties even when experiencing from slight to substantial changes in its chemical and physical environment.
Although not “prior art” in the present case, the present inventor is the author of the published article entitled “Polymerization of Rodlike Micelles”, published in Langmuir, Volume 15, pages 2726-2732 (published on the World Wide Web on Mar. 19, 1999 by the American Chemical Society). The experiments reported therein confirm that the counterion polymerization procedure discussed hereinbelow produces extremely stable cylindrical micelles with a well-defined cross section. The article also includes a complete description of the experimental procedures used for the preparation, and the details of the modeling of small-angle neutron scattering (SANS) data, also presented hereinbelow. The polymerized micelles described in the article are fluid, not solid.
The above-mentioned article by the present inventor states that, in the prior art, a large variety of surfactants and surfactant aggregate structures have been polymerized, with varying levels of success in retaining the original structure. Surfactant structures have been polymerized in the form of spherical micelles, lamellae, and hexagonal arrays of cylinders. Other than in liquid-crystalline phases, rodlike micelles have not been polymerized, although elongated structures have been proposed as the polymerization product of globular micelles. In view of the above, it would be desirable if micellar material were provided that includes rodlike micelles in a polymerized aggregate structure, that is in a solid phase and that is useful in material separation procedures.
In another published article entitled “Nanoporous Polymer Have A Thing For Organics”, by Elizabeth Wilson, published in Chemical and Engineering News, Feb. 1, 1999, pages 32 and 33, there is a disclosure of three dimensional, crosslinked cyclodextrin-based polymers which can remove compounds such as trichloroethylene from water. These cyclodextrin-base polymers have hydrophobic pores whose sizes can range from 5 to 11 Angstroms. The cyclodextrin-based polymers are formed from closed-ring cyclodextrin which has a specific molecular size and structure. As a result, the cyclodextrin-based polymers have hydrophobic absorption properties which are fundamentally based upon the molecular size and structure of cyclodextrin. Moreover, it is noted that cyclodextrin is not a surfactant, does not have a head and a tail, and does not have positive and negative ends such as found in a surfactant. Because of the wide range of absorption versatility provided by surfactants having a head and a tail and having positively and negatively charged portions, it would be desirable if a three dimensional, crosslinked material were provided which is based upon a network of ionic surfactants.
Thus, while the foregoing indicates it to be well known to use materials to separate hydrophobic solutes from other materials, the prior art described above does not teach or suggest a crosslinked micellar gel composition which has the following combination of desirable features: (1) provides a micellar material that has macroscopic dimensions; (2) has stable micellar properties even when experiencing from slight to substantial changes in its chemical and physical environment; (3) includes rodlike micelles in a polymerized aggregate structure, that is in a solid phase and that is useful in material separation procedures; and (4) provides a three dimensional, crosslinked material which is based upon a network of ionic surfactants. The foregoing desired characteristics are provided by the unique crosslinked micellar gel composition of the present invention as will be made apparent from the following description thereof. Other advantages of the present invention over the prior art also will be rendered evident.
SUMMARY OF THE INVENTION
To achieve the foregoing and other advantages, the present invention, briefly described, provides a composition that is comprised of a polymer formed by a reaction between (a) ionic surfactant units which include ionic surfactant molecules, each of which includes a counterion which has a first polymerizable functional group, (b) crosslinking agent molecules, each of which includes two second polymerizable functional groups, and (c) a reaction initiator selected from the group consisting of reaction initiator molecules and ultraviolet light radiation, wherein the reaction initiator initiates a reaction between a plurality of the ionic surfactant units with each other and a plurality of the ionic surfactant units with the second polymerizable functional groups. The polymer composition formed from the reaction is comprised of ionic surfactant micelles which are rodlike in shape.
The ionic surfactant units can consist essentially of ionic surfactant molecules, such that the ionic surfactant units form homopolymer units which react with the crosslinking agent.
Alternatively, the ionic surfactant units can further include co-monomer molecules each of which includes a third polymerizable functional group. The first polymerizable functional groups of the ionic surfactant molecules react with the third polymerizable functional groups of the co-monomer molecules to form co-polymer units, and the reaction initiator initiates a reaction between a plurality of the co-polymer units and the crosslinking agent to form the crosslinked micellar gel compositio
McClendon Sanza
Seidleck James J.
The United States of America as represented by the Secretary of
Townsend Marvin S.
LandOfFree
Crosslinked micellar gel composition does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Crosslinked micellar gel composition, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Crosslinked micellar gel composition will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2822241