Molecular recycling a difficult goal

The following interchange between Foresight President Christine Peterson and Our Molecular Future author Douglas Mulhall resulted from a Small Times column by Mulhall titled Incorporate disassembly into every self-assembled nanotech product, first brought to our attention by Senior Associate Robert Bradbury. In this article, Doug Mulhall says that nanotech products are already being produced which cannot be disassembled by current technologies, even incineration or (presumably) by acids, etc. Foresight President Christine Peterson asks readers whether this is true; can examples be cited? "This seems unlikely to me, but I'm willing to be educated if there are indeed examples of this."

Doug Mulhall responded to Christine Peterson's question:

It's absolutely correct to say that the statement 'no nanotech product can be disassembled' seems unlikely…if one takes that phrase out of context without reading the rest of the article or without considering the accompanying qualifying term, "in such pathways".

The foundation for environmentally effective disassembly is that it be done in definable, traceable pathways. I explain this prerequisite when I use the term "via measurable pathways" in my Small Times article. Right now such pathways are not established for many conventional products let alone nano-structured ones. Most importantly, current nanotechnology products are usually not defined when it comes to their interaction with thousands of other manufactured products in the environment.

The same goes for incineration of such products.

Looking back, we see that technical arguments in favor of incineration of conventional materials were made so convincingly that thousands of incinerators were constructed; the only problem being that the theory didn't match the practice. Millions of tons of toxins were–and are–spewed into the environment via particulates, gas, slag, and the building and decommissioning of the incinerators themselves. This was despite the claim that, in theory, these would be negligible.

Nanotech-enabled incineration might solve that, if done properly. But we have not seen it done in practice on a large scale. And there is another more serious problem:

Incineration does not address the messy reality that many materials get into the environment before they get to incinerators. They wear or leach off of our clothes, shoes, tires, computers, and thousands of other products. Again, theoretically they can be disassembled safely, but in reality they aren't, so that thousands of synthetic products are interacting with each other as they degrade.

Let's remember that although newer products may be nanostructured, their volumes are eventually macro. I want someone to tell me how billions of tons of nano-structured products will be recovered before they get into the environment and interact with each other. How for example might we prevent such materials from wearing off into soil and water as conventional materials do now, or how do we make sure that nano products which do get into the environment are designed to effectively degrade or be recovered?

If practicable disassembly pathways referred to in my article are already defined for every nanomaterial in existence then I'd like to see them. How for example will we disassemble materials containing gold, other persistent nanoparticles, and gallium arsenide when we manufacture trillions of products that contain thousands of such combinations and are used everywhere? How do we stop millions of permutations from interacting chemically with each other in the natural ecology, or alternatively make sure such combinations are safe?

The harsh reality is that few if any companies have demonstrated this yet. Therefore I'd like to reiterate that there is no practicable way to disassemble present nanostructured products via the measurable pathways described in my article. This is especially true once they are used everywhere by everybody.

HOWEVER, to be clear that I am not crying wolf about present impacts of nanomaterials, I state in my article that they are being manufactured now "in smaller quantities that so far have negligible impacts." We are not in a crisis yet. But we have to start planning to avoid one.

If someone wants to narrowly interpret three words in my article, "cannot be disassembled", without looking at the rest of the piece to understand what that term means, then yes the argument can be trashed, and everybody can go away feeling confident that nanotechnology products are easily disassembled and that there is no problem.

But if we want to recognize the truth that virtually no manufacturer of nanomaterials has figured how such products will be dealt with effectively, then let's have that discussion.

Some years ago I suggested that Foresight take up that task. I offered my services to do it. Then later I offered some small seed funding for IMM to investigate a related issue: how we might learn from newly discovered, naturally occurring self-regulating assembly. That is not the same concept but it got the same response. No one took it up and my check was sent BACK to me. The reaction so far is that everybody is too busy trying to figure how to make assemblers…just as we were too busy figuring out fission in earlier days.

Some at EPA and a few universities are looking at the environmental implications of nanotech, but few are tackling the big one…disassembly.

I argue in a Futurist article this month that innovations such as disassembly will be among the greatest gifts that nanotechnology gives us, because they will finally let us match nature's complexity instead of fearing or fighting against it.

The point that we seem to be missing is that disassembly IS what assemblers and their precursors are about. Disassembly will give us the flexibility to undo mistakes that we undoubtedly will make along the way. It will empower us to move more quickly from one strategy to another. So let's start incorporating disassembly into the process now, instead of rationalizing it by saying that everything can be incinerated.

Yes, everything is disassemblable eventually. It just has to work its way through a few thousand or million organisms, over years or decades, sometimes wreaking havoc along the way and sometimes not. That's why measurable degradation pathways are required, especially in ways that match the theory with the reality of how products are used and discarded.

Such templates exist now but are not being used or adapted. A good place to start using them would be with Carly Fiorina's initiative to make HP computers more environmentally compatible. That would make the work truly effective and produce a superior product.

Christine Peterson's response:

Hi Doug, I wish I could respond at length on this important issue … It would be good to continue this on Nanodot with more people.

Here's how I see the issue: disassembly, or what I call "molecular recycling", is the mirror image of the molecular assembler, which is a long way off currently. It's an advanced function. To me, it seems as though we need to focus on getting to that level of technology, so we can clean up the mess we've already made and continue to make. But we can't get there immediately, it will take an immense amount of work.

I may be wrong, that's just how I see it.

From Doug Mulhall:

The statement I responded to was whether existing nanomaterials can be practically disassembled by current technologies; not how far off molecular disassembly is. For existing nanomaterials, there is no practicable way to recycle many of them. It is not a crisis right now, but when these materials are made in the millions of tons–which may be very soon–then we'll have a problem.

However, on your thought that we need to focus first on getting to the assembler level of technology so we can clean up the present mess:

In my naivete I do not see the evidence that disassembly will be the mirror image of the molecular assembler. For example, when DNA directs the assembly of life forms, and then those life forms die and are recycled, this is often not the mirror molecular process. Nor is energy used and dissipated in mirror-like ways. The processes often don't run in reverse. They are cyclical and connected. It is this characteristic that is missing from the search for the molecular assembler.

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