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Nanotechnology


ChemSiddiqui
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Hi all,

 

Alright, I am going to start a whole new thread and hope that you people will chipp in with your views about this very hot topic of today's world.

 

"What is Nanotechnology? What future is there for it and how can it help to change our lives?"

 

Lets start this dicussion. I thought of this because I think nanotechnology should be discussed on a wider scale.

 

It is defined as " small science with large benifits". Nanotechnology is the study of materials as small as 10^ -9. Its first was discovery with the finding of Buckministerfullerene or simple bukyball, the 3rd allotrope of carbon.

 

well thats all I know for now. I will come back with more facts maybe even more interesting ones. In the mean time you also do the same.:)

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I've done work (and my current research is a preliminary experiment for nanostructures) on what can be described as nanotechnology. Optical devices are most of what I've been investigating for use with display devices and other applications. My current research is involved with magnets, and we're mainly aiming at data storage devices where there are nanostructures on the recording medium and also the read/write head of hard drives are nano devices. So they're already changing our world.

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During my Ph.D. (about 10 years ago!) I made some 100 nm polymers stripes on a Si substrate using e-beam lithography. My Wife for her Ph.D. makes 10 nm dots and spheres by polymerisation. So between us we are experts at making nana dots and stripes! :)

 

Very useful for someone I'm sure!! :D

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A problem with nanotechnology is that it has become a bit of a buzzword, similar to "systems biology". It lacks a coherent, stringent definition. In principle you can put so many things from different disciplines into that word so that it might essentially become (almost) meaningless (it just has to be small). In the few posts in this thread we have already seen examples of it. I could add plenty from the direction of biology and biochemistry. In scientific terms it is something under which you submit your grant application, if funds are available and you work with smallish things...

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problem with nanotechnology is that it has become a bit of a buzzword, similar to "systems biology". It lacks a coherent, stringent definition. In principle you can put so many things from different disciplines into that word so that it might essentially become (almost) meaningless (it just has to be small). In the few posts in this thread we have already seen examples of it. I could add plenty from the direction of biology and biochemistry. In scientific terms it is something under which you submit your grant application, if funds are available and you work with smallish things...

 

I think you may be right about it but you did admit that it has several uses. I think nanotech is still incomplete, it still needs people to make more inroads in jt. I just want this thread to explain what actually is nanotechnology so that those who are unaware of it should notice its importance.!

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Charon is correct, but I might add that I can state with some certainty that, in its current emobiment, nanotech is 98% hype and crap.

It has become simply a means to end....the end being obtaining (and wasting mostly) venture capital and/or government dollars using a silly buzz word. We could have built perfectly good bombs with that money.

 

Science and the world would benefit greatly if all the "Nanotech Centers" were disbanded and everyone went back to their rightful departments and focused on useful areas of science.......by that I mean stop this pissing contest to make everything smaller than the next guy for the sake of making it smaller than the next guy. Do something with it for God's sake.

 

Lord help the next doe-eyed person that comes to my door, nanotubes in hand, wanting me to do something cool with them; without any idea of a useful application that they could be used in themselves.

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Nanotech will be the next age I think, even if its a silent one that pretty much becomes a norm. The closest university to me has a materials science program offered by the physics department. The degree is interdisciplinary though overall, such as you have a big chunk of engineering courses, chem courses and of course physics courses. Personally I am to much of a lazy bastard for the most part though and would probably end up blowing myself up or something I am sure:D ;)

 

Quantum dots though, or in conjunction with nanotech is I guess making better targeted drug delivery a reality, such as very acute. I think the ability to say engineer at such a small "dimension" of reality is hardly realized for what it could be right now, for instance chemistry is realized and its atomic in scale. Plus to go smaller would basically require you to go through at least some form of nanotech for the ability to build at such a level that is not just chemistry alone.

 

Also being the field is still "new" in many ways its not so locked down as to be boring really. I mean could you imagine making an intricate machine with gears smaller then a dust mite? Its pretty cool but like to many things environmental impact is not part of the core curriculum so to speak, its simply not profitable even while nanotech could have a vast array of environmental applications.

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DrDNA, while I agree that most of what calls itself nanotech is just there for the free money, I do think at least some good will come of simply making things smaller. In the end, there will have to be completely different methods to do things, but we need something to start from.

 

My own view of this is that we could consider proteins to be nanotech, and start from there. The advantages are that we already have self-replicating, hardy cells that could be used, as well as a rather easy method for constructing them (just put the proper DNA in the proper place, and it will make your protein for you). It's a tried and tested system, and it works very well already.

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DrDNA, while I agree that most of what calls itself nanotech is just there for the free money, I do think at least some good will come of simply making things smaller. In the end, there will have to be completely different methods to do things, but we need something to start from.

That's why I said 98% and not 100%. Of course there is some good in it but for the most part, it is true that the money could be wiser spent and more thoughtfully applied to other areas like cancer research, gasification and noncarbon based energy, food productivity, pollution, the list could go on for a mile. We need to quit funding projects because somebody included the word "nanotechnology".

 

Flush the hype, keep the science.

 

 

Quantum dots though, or in conjunction with nanotech is I guess making better targeted drug delivery a reality, such as very acute.

Quantum Dots are not making targeted drug delivery a reality at all.

Although Quantum Dots are great little tags or labels for in vitro assays (they don't bleach like organic fluorphores) they so far have proven to be much too toxic to be effectively applied in vivo.

 

Until the human species evolves to a state of being immune to cadmium poisoning, this will remain an issue and Quantum Dots shall be confined to the Pitre dish or in vitro assays.

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"Quantum Dots for Live Cells, in Vivo Imaging, and Diagnostics

X. Michalet,1* F. F. Pinaud,1* L. A. Bentolila,1 J. M. Tsay,1 S. Doose,1 J. J. Li,1 G. Sundaresan,2 A. M. Wu,2 S. S. Gambhir,2,4 S. Weiss1,3*

 

Research on fluorescent semiconductor nanocrystals (also known as quantum dots or qdots) has evolved over the past two decades from electronic materials science to biological applications. We review current approaches to the synthesis, solubilization, and functionalization of qdots and their applications to cell and animal biology. Recent examples of their experimental use include the observation of diffusion of individual glycine receptors in living neurons and the identification of lymph nodes in live animals by near-infrared emission during surgery. The new generations of qdots have far-reaching potential for the study of intracellular processes at the single-molecule level, high-resolution cellular imaging, long-term in vivo observation of cell trafficking, tumor targeting, and diagnostics."

 

http://www.sciencemag.org/cgi/content/abstract/307/5709/538

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I am familiar with this and similar studies. For every paper speculating that Quantum Dots are magic bullets, there is another one that points to toxicity. The bottom line is, Cadmium and Selenium are highly toxic materials.

 

Environmental Health Perspectives Volume 114, Number 2, February 2006

A Toxicologic Review of Quantum Dots: Toxicity Depends on Physicochemical and Environmental Factors

 

............Cadmium and selenium, two of the most widely used constituent metals in QD core metalloid complexes, are known to cause acute and chronic toxicities in vertebrates and are of considerable human health and environmental concern (Fan et al. 2002; Hamilton 2004; Henson and Chedrese 2004; Kondoh et al. 2002; Poliandri et al. 2003; Satarug and Moore 2004; Spallholz and Hoffman 2002). For instance, Cd, a probable carcinogen, has a biologic half-life of 15-20 years in humans, bioaccumulates, can cross the blood-brain barrier and placenta, and is systemically distributed to all bodily tissues, with liver and kidney being target organs of toxicity. The potential environmental impacts of Se contamination are well understood from Kesterson Reservoir, California, and Belews Lake, North Carolina, where a marked impact on the local ecosystem resulted from elevated environmental concentrations of Se. Because of QD metalloid core composition, the uniqueness of each type of QD, the oxidative and photochemical lability of certain types of QDs, and the dearth of information on routes of exposure and the environmental transport and fate of QD materials, the potential risks posed by QD materials to human health and the environment should be seriously considered.

....................

In summary, the findings in these reviews suggest that under certain conditions QDs may pose environmental and human health risks as determined by rodent animal models and in vitro cell cultures.

 

http://www.ehponline.org/members/2005/8284/8284.html

Those "certain conditions" being inside the body.

The FDA has a difficult time approving toxic materials for internal human use.

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Might I suggest that we keep this thread for information basis about Nanotechnology Only. True there are shortcomings with this field because its relatively recent branch of science. but, we will see good about it. As i just learnt that the nanotubes can be used to perform complex reaction without any environmental influences like air toxication etc they can be highly useful for coming generation of scientists because it will make future reactions whatever they may concern very effective!

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"without any environmental influences"? Oh dear Lord. Please tell me how that works.

 

"Might I suggest that we keep this thread for information basis about Nanotechnology Only"

 

"information" or mis"information"?

I did not realize this was a promotional segment. I surrender.

I'm going to eat a 3 bowls of fruit loops with extra sugar and watch the National Geographic Channel. Then it's off to the beach to stick my head in the sand and try to unlearn the years I've spent studying and practicing chemistry, pharmacology, biology, and quote unquote "nanotechnology". Maybe then I can get with the program.

 

In passing, I would like to add that this thread is in General Chemistry. Therefore, if whatever you, I, or anyone else have to say about "nanotechnology" holds water, it should be able to withstand the test of objective scientific discourse from all angles (including positive and negative....the laws chemistry and physics, environmental, toxicological, physiological aspects, etc etc). If not...well, then it may not.

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"without any environmental influences"? Oh dear Lord. Please tell me how that works.

 

"Might I suggest that we keep this thread for information basis about Nanotechnology Only"

 

"information" or mis"information"?

I did not realize this was a promotional segment. I surrender.

I'm going to eat a 3 bowls of fruit loops with extra sugar and watch the National Geographic Channel. Then it's off to the beach to stick my head in the sand and try to unlearn the years I've spent studying and practicing chemistry, pharmacology, biology, and quote unquote "nanotechnology". Maybe then I can get with the program.

 

In passing, I would like to add that this thread is in General Chemistry. Therefore, if whatever you, I, or anyone else have to say about "nanotechnology" holds water, it should be able to withstand the test of objective scientific discourse from all angles (including positive and negative....the laws chemistry and physics, environmental, toxicological, physiological aspects, etc etc). If not...well, then it may not.

 

O alright, alright. I was merely suggesting to keep this disscussion friendly! but I must admit i found your comments rather funny (no offence!:embarass: ). I also confirm that i am not ridiculing your experience with chemistry work, which i am sure would be great!. But its my personal opinion as i read a lot of ChemistryWorld magazine published by the Royal Society of Chemistry, that nanotechnolgy has a future that human can benefit from. Good day!:)

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Nanotechnology is a broad term covering areas from computers to biology. Is there are particular approach to nanotechnology about which you are especially curious, Chemsiddiqui? Clarifying or limiting that may help your thread to gain some momentum. :)

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DrDNA,

if there were conductive and non-conductive nanotubes for reasonable prices (with a special focus on the price) I might actually be interested.

Another problem with nanodots as labels, btw, is their ability to blink. Not few measurements screwed up due to this.

In a way the phrase: "nanotechnology is the future" has a lot of truth to it. The majority is still is still in the area of basic research, meaning that only few of the current ideas will eventually hold water- in the future.

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Is there are particular approach to nanotechnology about which you are especially curious, Chemsiddiqui?

 

Sure, I was particularly impressed by nanotubes which I found to be of great importance in the future. Like drug delivering for example. If any one can discuss how this is done and what is the mechanism, I think i'd like that.

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Sure, I was particularly impressed by nanotubes which I found to be of great importance in the future. Like drug delivering for example. If any one can discuss how this is done and what is the mechanism, I think i'd like that.

 

http://nano.cancer.gov/news_center/nanotech_news_2005-08-22d.asp

 

By combining nanoscale liposomes and microtubules, researchers at the University of California in Santa Barbara have developed a nanotube that can essentially open and close in response to a chemical stimulus. This hybrid system, developed by a team led by materials scientist Cyrus Safinya, Ph.D., and biochemist Leslie Wilson, Ph.D., of the University of California in Santa Barbara, is discussed in a paper appearing in the Proceedings of the National Academy of Science USA.

 

Microtubules are nanometer-scale hollow cylinders derived from a cell’s internal skeleton. In a cell, microtubules and their assembled superstructures are critical components of a broad range of cell functions, including transport of cargo within a cell to forming the spindle structure needed to separate paired chromosomes during cell division.

 

The hybrid device owes its existence to a newly observed form of self-assembly that arises because of an extreme mismatch between the charge density of the liposomes and the microtubules. Charge density refers to the amount of positive charge in the case of the liposome or negative charge associated with the microtubule over a given surface area. By controlling the degree of mismatch between the two components, the liposome will either cover the opening of the hollow microtubule or move aside. The research team was able to visualize this opening and closing using state-of-the-art synchrotron x-ray scattering and electron microscopy techniques.

 

The researchers note that this ability to open and close a microtubule could form the basis for controlled drug encapsulation and release. In fact, the investigators have already begun formulation work with the anticancer drug Taxol®.

 

This work is detailed in a paper titled, “Cationic liposome-microtubule complexes: Pathways to the formation of two-state lipid-protein nanotubes with open or closed ends.” An abstract is available through PubMed.

 

View abstract.

 

 

:)

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My PhD was in nanomaterials, and it went to show for the first time that a molecule could act as an electrical rectifier.

 

I think nanotechnology is great

 

however, there are bandwagons, and people will jump on them

 

The trouble with nanotech at the current time is that it makes so much money and interest that everyone and his wife is interested in studying it. Which means there's a ton of crappy research going on and only a few genuine diamonds shining amongst the rough.

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I was particularly impressed by nanotubes which I found to be of great importance in the future. Like drug delivering for example. QUOTE]

 

 

Wow - and just think that people used to use series 3 white BMW's!

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