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NSC's Design Platform

NSC's Nanopolymer Design Platform™ is a systematically organized set of tools for designing and manufacturing nanostructured materials and nanostructured devices.  The vision for the NDP is two parts.  First is the hardware portion, consisting of vector-directional monomers and oligomers as the "parts" that are to be combined to make a material or supramolecular assembly.  Second is the software portion, whereby structure can be predicted from the sequence of parts, and the assembly sequence (the polymer recipe) can be predicted from any polymer design [see Note #1].

Both of these portions will require significant development to realize.  The vector-directional monomers will require synthesis.  Although some of the basic monomers have been synthesized in the past, only a few are available on a commercial basis and world production of those is minimal.  A large organic-chemistry team is required for developing new syntheses [see Note #2], and scale up will be needed for existing monomers [see Note #3].

Software systems will also require developmental time.  However, a co-development partnership with an existing molecular-modeling company will likely shorten the time-to-market significantly [see Note #4].

Once the library of vector-directional monomers is substantial and the software is reliable, they can be incorporated into Nanopolymer Development Kits.™   These NDKs would be attractive research-and-development tools for small companies, and for R&D departments of major corporations [see Note #5].

The Core Library for Iminol Polymers

The below illustration (Figure 1) shows a minimalist library of vector-directional iminol monomers.  The structural diagrams of the monomers are in the middle, with the six possible hydroxy-acid monomers on the top and the six possible heterocyclic amines on the bottom, and with the six inverting monomers on the left (in red) and the six non-inverting monomers on the right (in blue).  (Actually, there are only four inverting monomers because monomer A is the same as monomer C and monomer 1 is the same as monomer 3.)

The vectors are illustrated above and below the monomers with oligomers (polymer segments) with gray arrows pointing from the center of the previous monomer to the center of the following monomer to show the vector change.  The vector quantity is defined by a distance and direction.  Because all of these monomers are single-ring structures and because the linkages are all identical, these vectors differ primarily in direction.

In Figure 2, monomer pairings are illustrated to show the results of pairings of non-inverting monomers (shown in blue in Figure 1).  Here we chose to pair monomer 5 with monomers D, E and F, and a non-standard monomer, X, in which two secondary bonding features are provided by one secondary bonding group through the use of a magnesium (Mg) ion instead of a proton (hydrogen ion).

The 5-E pairing, with offsetting -38˚ and +38˚ vector directions, zig-zags through the center of the illustration. The 5-F pairing, with two negative vectors, curves uniformly. Note that the -38˚ and -32˚ vector directions combine to create a near-60˚ vector for a total of twelve monomers per 360˚ circle. The 5-X pairing creates a near-120˚ combined vector, which completes 360˚ of curvature in only six monomers. The 5-D pairing has vectors of opposite sign, but the positive vector is greater and the curvature is opposite the 5-F and 5-X polymers.  In other words, in the 5-D polymer the 5 monomer is inside-out compared to the 5-F and 5-X polymers.  In this system of nanostructural self-assembly, it is possible to turn a polymer coil (or nanotube) inside out merely by reversing the vector quantity of a co-monomer.

In figure 2, we illustrated pairings involving only non-inverting monomers.  Contrast these with Figure 3 in which monomer 5 (a non-inverting monomer) is combined with inverting monomers (A, B and C from Figure 1).

The inverting monomers reverse the vector quantities of subsequent monomers. So you can see that monomer 5 changes from -38˚ vector direction to +38˚ vector direction, and then back again. This is because the A, B and C monomers reverse all the vector signs of downstream monomers. Please note that this reversing of sign also applies to downstream inverting monomers, so that the A monomers change from +60˚ to -60˚ and back to +60.

This also applies to the B and C monomers, except that the vector direction of the B monomer changes from +0˚ to -0˚ and back to +0˚. Since +0 and -0 are the same, the sinusoidal oscillations of the polymer are minimal. (Please also not that monomer A and C are the same monomer, only rotated, so that the resulting 5-C and 5-A polymers are actually also the same.)

Expanding the Took Kits

So far, our toolsets have contained monomers of closely comparable size, so the differences are mainly in vector direction and not in vector distance.  But with Figure 4, we show how adding a second ring to a monomer changes both the vector direction and the vector distance.  This gives researchers a rich toolset for designing subtleties into nanostructures.

The old vectors (from the single-ring monomer) are illustrated in pale gray arrows, and the new vectors are illustrated by medium-gray arrows. As you can see, there are significant variations in vector quantity by substituting a two-ring monomer for a one-ring monomer. There is also another potential benefit. The two-ring monomers on the extreme right and extreme left are not possible with single-ring monomers due to position conflicts on the single ring. While it is possible to accommodate two secondary bonds with one secondary bonding group (see monomer X in Figure 2), it is not possible to accommodate two primary bonding groups or a primary and secondary bonding group on the same ring position. The bottom line, multiple rings can accommodate a greater number of vector opportunities.

So this new, expanded toolset of one-ring and two-ring iminol monomers now includes 24 monomers (see Figure 5).

This monomer set is comprised only of symmetric monomers, for which the vector quantity does not change depending on which of the two primary functional groups reacts first.

Expanding the Kits

There are many more monomers that are asymmetric (for example, see monomers 1, 3, A and C in Figure 1) that might be included for an R&D environment employing solid-phase synthesis, were only one monomer is added at a time.   In such an environment, the desired primary group is left in its reactive state, and the other primary group is blocked by a removable functional group. After each monomer is added, the blocking group is removed before the next monomer is reacted.

With the set of monomers in Figure 5, blocking groups are not necessary. With these monomers, the same vector result is obtained regardless of which primary group reacts first.

All of these 24 monomers use six-membered rings, which imposes the limitation of near-60˚ geometries to the design. The alteration of the position of a six membered ring tends to shift the vector by exactly the distance and direction of the single ring (see Figure 6a).

Vector Subtleties

What is other vector directions are desired, or needed?  One solution is to incorporate five-membered rings.  This gives 12˚, 24˚, 36˚, 48˚ and 72˚ geometries which result in more subtle variations in vector quantity affecting both distance and direction.

In Figure 6b, the shift of the position and orientation of a five-membered ring between six-membered rings causes a variety of shifts in vector quantity.  The black comparative structure sits in front of the red alternative structure to hide the identical structures and only show the differences.

Rotation of the positions of the five-membered rings (Figure 6c) produces similar results but with the potential for more acute vector angles.

Summary

These illustrations show that vector-directional polymers provide ample potential for fine control of nanostructural designs.  While the demand for individual monomers and specific vector quantities may be impossible to predict in advance of actual demand, the high concept for packaging sets of monomers suited to specific design environments is a potentially profitable business line.

Notes and Elaborations

Note 1:  A third part might be an integrated laboratory device for the automated synthesis of nanopolymers.  This might be accomplished through a co-development partnership with an existing company currently producing automated peptide synthesizers.  No inquiries have been initiated along these lines. [Return to main text.]

Note 2:  The required number of different monomers may be quite broad.  Positive vector, negative vector and zero-vector monomers, inverting and non-inverting monomers, tri-functional and tetra-functional monomers, aliphatic-cage (non-conducting) monomers, and a wide variety of vector quantities (sizes and angles).  The selection of monomers in kits could be specific for particular industries. [Return to main text.]

Note 3:  For building nanodevices in a research environment, the amounts of the monomers in the Nanopolymer Development Kits™ do not need to be high.  One gram of a monomer contains at least a thousand million billion molecules, which if used a million per day would take a lifetime to consume.  On the other hand, for making bulk materials, a gram might be used in a single shot.  So easy-refill ordering capabilities and scale-up options would need to be incorporated into the kits. [Return to main text.]

Note 4:  Initial introductions have been made to one company, with interest expressed. [Return to main text.]

Note 5:  Commercial interest in Nanopolymer Development Kits™ might be augmented by incorporating standard licensing agreements as part of the kit, thus minimizing the associated costs of licensing NSC technologies.  Although this might seem much more directed towards small companies and "garage" inventors with limited funding, it could also be attractive to large companies with risk concerns related to developing product before licensing terms are known.  We suggest that this is an excellent business opportunity that should be studied during phase-2 development. [Return to main text.]

Elaboration:  Other Polymer Systems (and Monomer Adapters)

The illustrations and discussion up to this point have been limited to iminol polymers, due to their advantageous structural, chemical and synthesis features.  However, there are other, different classes of vector-directional polymers for which monomer toolkits can be developed.  The bisoxazole and aramid polymer classes are the most notable examples.

There is no reason why toolkits cannot contain multiple sets of monomers capable of making more than one kind of vector-directional polymer.  Indeed, bisoxazoles are fundamentally more suited to making stiff, rigid-rod segments that might be needed for rigidity in a particular nanostructural design.  If so, then adapter monomers can be included for connecting these different polymer/oligomer sub-components together into the finished product.  These adapter monomers have one kind of primary and secondary bonding groups on one side of the adapter monomer and a different kind of primary and secondary bonding groups on the other side of the adapter monomer.

Elaboration:  Proprietary Considerations

Since NSC's patents do not cover monomers, the toolkit product line is not fundamentally proprietary.  Most of the single-ring monomers are already known.  Some of these monomers have multiple syntheses which have been published in the chemical literature.  This makes many of the kit's mainstay monomers generic.

NSC could patent (as new chemical entities) certain monomers that have never been synthesized before.  Multi-ring monomers are likely to be novel structures.  However, it is equally possible (and even likely) that new-chemical-entity monomers would be synthesized and patented by other individuals and companies.

Even in situations where monomers are generic and unpatentable as new chemical entities, patents can be filed on new synthetic methods.  For example, Trinapco has patented a new way of making 2,7-diamino-1,8-naphthyridine that is quicker, more efficient, and less expensive than earlier syntheses.  Therefore, it makes sense that NSC's strategy regarding kits should be focused on marketing advantages, licensing efficiencies and monomer inclusivity.  We have a potential co-development partner selected to work with us on this product line.


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