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Nanostructures

The basic nanostructural geometries made possible by vector-directional polymers are described below. Each of these geometries is specifically enabled by the patents, even though there may be redundant versions of some geometries that are not vector directional.  Implementations of these geometries to specific applications are described in detail in our confidential internal working documents, but some are briefly described immediately following to provide context suited to this document’s purpose.

There are two types of polymer construction that can be accomplished with NSC’s patents:

     Type 1: synthesis of simple (homogeneous) nanostructured materials, and

     Type 2: synthesis of custom supramolecular structures (heterogeneous polymers).

Type 1:   Simple or homogeneous materials

Simple materials may be made from only two monomers (A and B) which are mixed together to make an ABAB polymer sequence [see Note #1 for elaboration.  Since neither monomer A nor monomer B can react with itself, a single reaction step leads to:

          A────B────A────B────A────B

The A monomer can be replaced with an A-C-A oligomer [Note #2] (a mini-polymer segment) to make:

        ACA───B───ACA───B───ACA───B

Note that A is still reacting with B to make the polymer.  So this is basically the same reaction as the first example.  Monomer C was reacted in a previous step and does not participate in this reaction step.

Then, if we also replace the B monomer with a B-Y-X-Y-B oligomer, we get:

        ACA─BYXYB─ACA─BYXYB─ACA─BYXYB

Note again that the A monomer is still reacting with the B monomer.  Like the C monomers, the X and Y monomers are embedded in an oligomer and do not participate in this reaction.  So these types of simple nanostructured materials can actually incorporate more than two monomers, but not more than two in each reaction step.

A. Linear polymers and sinusoids

These polymeric structures are similar to existing-art tensile polymers and rigid-rod polymers.  Although they have the least novelty of NSC’s portfolio, their hydrogen-bonding members should have novel self-repair properties that other existing-art polymers do not.  In addition, linear and sinusoidal oligomers can be used as sub-components in larger supramolecular assemblies (Type 2 materials, see below).

B. Coils, tubes, helices, circles, hexagons, polygons

These are not found in the existing art.  Coils are quite novel and probably very useful across a spectrum of applications.  Coils may have circular, hexagonal or polygonal cross sections, which affect local stress points and packing geometries of groups (bundles) of nanotubes.  For small diameters (2-5 nm), hexagonal tubes are easiest to synthesize.  For larger diameters (30-300 nm), circular tubes are likely easiest, although the insertion of straight oligomers into small hexagonal tubes makes larger hexagonal tubes.  Packing geometries are optimized for triangular, square, hexagonal and octagonal tubes.  Hexagonal tubing may be optimal for bundling tubes together for connection to larger tubes [Note #3] for branched networks, for application to nano-hydraulic, nano-refrigeration and nano-heating systems.  Non-cross-linked tubing may provide highly unusual elastic properties. Cross-linked nanotubes may be tough and rugged, yet maintain substantial axial flexibility.

C. Planar arrays (pi systems parallel to plane)

Pi-linked networks may result in nanofilms of high semiconducting uniformity.  Such films may be very tight and impermeable to gases, or they can be quite loose and porous to liquids or capable of filtering particulates.  Monomer selection can also result in holes or “pores” of particular chemistries.  Registered stacking of films is also possible.  Local and global aromaticities may be exploitable for nano-solar, photovoltaic, capacitance or optical filtering applications.  Films might be rolled into multi-walled tubes.

D. Planar weaves (pi systems perpendicular to plane)

The nanoWeave matrix and nanoLattice array offer distinct differences from planar arrays.  Semiconductive pathways are oriented perpendicular to the plane, altering the photon-absorbing properties of the aromatic system for directional light pathways and facilitating attachment of large pendant photon-absorbing groups oriented perpendicularly to the plane of the weave/matrix and capable of full electron resonance with the polymer backbones.  Note: right-angle-oriented semiconducting pathways are isolated (not pi-linked) due to a 90° twist in the octafunctional monomers [see Note #4 for further discussion].

E.  3-D arrays

The nanoWeave can be extended into three dimensions through inversion of nanoWeave and nanoLattice monomers’ primary and secondary reactive groups.  Planar arrays can be extended into three dimensions by stacking, or by decreasing the backbone angle at the tetrafunctional hub from 180° to 120° or as close to 109° as convenient.  Use of metals and non metallic (as ions and/or atoms) with trigonal, tetrahedral, octahedral or other, more complicated geometries will also likely produce 3-D arrays and matrices.

F. Combinations of the above

The above nanostructure geometries may be combined in multiple ways. This leads to materials of Type 2, immediately following.

Type 2: Complex or heterogeneous materials

Type 2 nanostructures are custom supramolecular structures involving heterogeneous sequences of many different monomers.  These structures must be synthesized in a multi-step process, analogous to the way peptides (small proteins) are assembled from individual amino acids by modern peptide synthesizers.  Since these materials are based on heterogeneous monomer sequences, their nanostructures are idiosyncratic and do not fit within the uniform geometric categories above.

Custom-designed supramolecular assemblies can also be created by splicing together heterogeneous sequences made from one polymer family with those made from another polymer family. Custom “adapter” monomers that combine bonding structures from two or more polymer classes will make this possible.

Note #1:  In this scenario, we describe the mainstream approach to making polymers, where the A monomers have two heads (each head of which has an arm next to it) and the B monomers have two tails (each tail of which has a leg next to it). This results in the A-B-A-B polymer sequence as described. If, instead, the A monomer had one head, one tail, one arm and one leg, the polymer sequence would be A-A-A-A.

Note #2:  The ACA oligomer is made by slowly adding C monomer to a large excess of A monomer. With the A monomer in excess, every C monomer reacts with two As to form ACA oligomer. If done carefully, only small amounts of ACACA oligomer and tiny amounts of ACACACA oligomer will result. The high yield ACA oligomer is then separated from the unreacted A and the larger oligomers by chemical purification.

Note #3:  This application requires a higher-order nano-assembly process than the basic polymerization scheme. 

Note #4:  These octafunctional monomers use eight functional groups, or four sets of the two (paired) functional groups.  A paired functional group would be the combination of a head and arm (or a tail and leg) by the previously developed head-bites-tail analogy.  The simplest octafunctional monomers use ring-to-ring linkages twisted 90° from their coplanar conformation, which completely disrupts the ring-to-ring resonance.  However, the extremely close proximity of isolated orbitals may allow substantial electron tunneling between orbitals. To block tunneling and “insulate” the two pathways from each other, a different monomer design would have to be devised.

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