Tag Archives: Nanochannels

Sound-absorbing nanofoam

In these increasingly noisy days (there’s construction going on around me), news of a cheaper, easier way to dull the noise is very attractive. From a June 25, 2018 Far Eastern Federal University (Russia) press release on EurekAlert,

The breakthrough material reduces a noise level by 100% more efficient comparing to standard analogs, cutting the level of noise transmission by 20-22 dB. The new foam reacts to sound waves not only of high but also of low frequencies, which can damage human health. A young scientist from the Far Eastern Federal University (FEFU) took part in the development.

PARTNERSHIP DEVELOPMENT

Alexey Zavjalov, postdoc, researcher at the Academic Department of Nuclear Technologies School of Natural Science, FEFU, worked as a part of the international team of Russian and South Korean scientists under professor S.P. Bardakhanov. Alexey’s research performance led to the creation of nanofoam – the new noise-absorbing composite material. The results of the work are published in ‘Applied Acoustics’.

‘The problem of noise is the problem of modern technogenic civilization. In South Korea, cities are equipped with round-the-clock working stationary and mobile networks for noise levels monitoring. The urbanization level of such territorially small countries as South Korea is much higher than in Russia. However, in our country this problem is still crucial for big cities,’ – explained Alexey Zavjalov. – ‘The development of new noise-absorbing materials is especially interesting for the automotive industry. Modern people spend a lot of time driving cars and the noise level inside the vehicles’ directly determines the quality of life. For East Asian countries, the issue of noise control is relevant for high-speed rail lines.’ Porous materials are excellent sound absorbers but their noise-absorbing properties can be significantly enhanced by nanoporous grit injected into the foam structure and formed internal channels in it. Alexey Zavjalov has developed approaches for saturation of macroporous foam material with nanoporous grit.

HARMFULNESS OF THE LOW FREQUENCIES NOISES.

Along with the rapid development of nanotechnology, there have been many attempts to mix nano- and microsized materials to create a modified material with enhanced strength, elastic, dynamical and vibrational properties. The acoustic parameters of such materials could not be fundamentally enhanced thus far.

Foam materials are most often used for soundproofing purposes. They provide the proper quality at a reasonable cost, but until today have been effective against high-frequency noise only. At the same time, low frequencies can be much more harmful to human health.

Infra- and low-frequency vibrations and noise (less than 0.4 kHz) are most harmful and dangerous for human health and life. Especially unfavorable is their long-lasting impact, since leads to serious diseases and pathologies. Complaints on such oppressions exceed 35% of the sum total of complaints on harmful environmental conditions.

The foam material, developed by Russian and Korean scientists, demonstrated promising results at medium frequencies and, therefore, more specialized low-frequency noise tests are needed.

CHEAPER AND EASIER FOR APPLICATION THAN AEROGEL.

The improved acoustic characteristics of the newest hybrid nanofoam were obtained by additional impregnation of the standard off-the-shelf sound-absorbing foam with porous granules of silica and magnetite nanoparticles. The porous foam was immersed in nanopowder suspensions in the liquid, subjected to ultrasonic treatment and dried.

The nanoparticles granules formed in the result can be compared structurally to a widely known class of materials – aerogel. It has not only excellent thermal insulation properties but also has a good noise-proof. However, aerogels are quite expensive and complex when used in structures. The new material, created according to the scheme developed by the FEFU researcher, is structurally similar to aerogel but is free of such shortcomings as a high price and engineering problems.

COMPOSITE TECHNOLOGY

The mechanism of sound absorption of a new foam is based on the fact that its sound-absorbing surface is significantly scaled due to the presence of a large number of nanopores in the particles injected, as well as the location of these particles in the foam matrix in the form of distinct channels. Nanoparticles dissipate the energy of a sound wave transforming it into heat. The soundproof properties of the material increase.

Scientists found out that the composite structure is most effective for noise reduction. Thin layers of foam impregnated with nanoparticles are connected to each other in a “sandwich”-construction. This design significantly improves the soundproof properties of the resulting material. The outcome of the study also suggests that the more foamy material is impregnated with nanoparticles, the better it’s sound absorption is.

‘In some approximation, any material can be represented as a network of weights connected by springs. Such a mechanical system always has its own frequency bands, in which the oscillations propagate in the system relatively freely. There are also forbidden frequency bands in which the oscillations rapidly fade out in the system. To effectively extinguish the transmission of oscillations, including sound waves, the materials should be alternated in such a way that the fluctuations that propagate freely in the first material would be in the forbidden band for the second layer,’- commented Alexey Zavjalov. – ‘Of course, for our foam material, this idealization is too crude. However, it allows us to clearly illustrate the fundamentally conditioned necessity of creating a “sandwich” structure.’

RESEARCH OUTCOME

The study showed the effectiveness of the method of foams impregnation with nanosilica or nanomagnetite, which form granules up to several hundred micrometers (in accordance with the pore sizes of the modified foam material) and having pores about 15 nm. This small addition provided a more complex and branched 3D network of nanochannels which led to an additional absorption of noise energy.

Due to the method used, the noise absorption efficiency was achieved in the range of 2.0-6.3 kHz and at lower frequencies 0.5-1.6 kHz. The degree of absorption was increased by 60-100% and the sound transmission was reduced by 20-22 dB, regardless of the type of nanofiller.

‘There is room to further improve the sound absorbing properties of the new material for medium and low frequencies using the” active control” strategy’. – Alexey Zavjalov comments on the plans for further development of such an important scientific topic. – ‘First of all, this refers to the materials obtained by using a magnetite nanopowder. Active noise protection systems have long been used in the world. The main idea is to detect the noise acoustic fields “online” and to generate sound waves in antiphase by means of loudspeakers. That allows achieving a significant reduction of noise in a given area. Concerning the nanofoam, it’s proposed to adapt this approach and to actively exert on a material saturated with granules of magnetite nanoparticles by magnetic fields. This will achieve even better noise reduction.’

Here’s a link to and a citation for the paper,

Hybrid sound-absorbing foam materials with nanostructured grit-impregnated pores by S.P.Bardakhanov, C.M.Lee, V.N.Goverdovskiy, A.P.Zavjalov, K.V.Zobov, M.Chen, Z.H.Xu, I.K.Chakin, D.Yu.Trufanov. Applied Acoustics Volume 139, October 2018, Pages 69-74
https://doi.org/10.1016/j.apacoust.2018.04.024 Available online 23 April 2018.

This paper is behind a paywall.

If you have difficulty seeing the press release on EurekAlert, there is a June 26, 2018 news item on a Russian news site, RSF News and there is an edited version in a June 26, 2018 news item on Azonano.

The UK’s Guardian newspaper science blogs go nano and experiment with editorial/advertorial

Small World, a nanotechnology blog, was launched today (Tuesday, Apr. 23, 2013)  on the UK’s Guardian newspaper science blogs network. Here’s more from the Introductory page,

Small World is a blog about new developments in nanotechnology funded by Nanopinion, a European Commission project. All the posts are commissioned by the Guardian, which has complete editorial control over the blog’s contents. The views expressed are those of the authors and not the EC

Essentially, Nanopinion is paying for this ‘space’ in much the same way one would pay for advertising but the posts will be written in an editorial style. In practice, this is usually called an ‘advertorial’. The difference between this blog and the usual advertorial is that the buyer (Nanopinion) is not producing or editing the content. By implication, this means that Nanopinion is not controlling the content. Getting back to practice, I would imagine that the Guardian editors are conscious that is an ethically complicated situation. It would be interesting to see what will happen to this paid-for-blog if ‘too many’ posts are negative or if their readership should decide this setup is so ethically questionable that they no longer trust or read the newspaper and/or its blogs.

The first posting on this blog by Kostas Kostarelos, professor of nanomedicine at University College London, on Apr. 23, 2013 is thoughtful (Note: Links have been removed),

There is beauty in exploring the nanoscale. But the idea gets more tainted the more we learn about it, like a young love affair full of expectation of the endless possibilities, which gradually becomes a dysfunctional relationship the more the partners learn about each other. One day we read about wonderful nanomaterials with exotic names such as zinc oxide nanowires, say, or silver nanocubes used to make ultra-efficient solar panels, and the next we read about shoebox bomb attacks against labs and researchers by anti-nanotechnology terrorist groups. It makes me wonder: is there a particular problem with nanotechnology?

As with all human relationships, we run the risk of raising expectations too high, too soon.

He goes on to discuss the dualistic nanotechnology discourse (good vs bad) and expresses his hope that the discourse will not degenerate into a ceaseless battle and says this,

… We should not allow vigilance, critical thinking and scientific rigor to transmute into polemic.

As someone who lives and breathes exploration on the nanoscale – which aims to create tools for doctors and other health professionals against some of our most debilitating diseases – I hope that this blog will offer an everyday insight into this journey and its great promises, flaws, highs and lows. We want to offer you a transparent and honest view of nanotechnology’s superhuman feats and its very human limitations.

I have mentioned Kostarelos in past postings, most recently in a Jan. 16, 2013 posting with regard to his involvement in a study on carbon nanotubes and toxicity.

As for Nanopinion, it put me in mind of another European Commission project, Nanochannels, mentioned in my Jan. 27, 2011 posting,

From the Jan. 17, 2011 news item on Nanowerk,

Nanotechnology issues are about to hit the mass media in a big way. The new EC-funded NANOCHANNELS project was launched last week with a two-day kick-off meeting that led to the planning of a dynamic programme of communication, dialogue, and engagement in issues of nanotechnology aimed at European citizens.

Here’s how they describe Nanopinion (from the About Nanopinion page),

Nanopinion is an EC-funded project bringing together 17 partners from 11 countries with the aim of monitoring public opinion on what we hope for from innovation with nanotechnologies. The project is aimed citizens with a special focus on hard-to-reach target groups, which are people who do not normally encounter and give their opinion nanotechnologies at first hand.

Dialogue is facilitated online and in outreach events in 30 countries presenting different participatory formats.

To promote an informed debate, we also run a strong press & social media campaign and offer a repository with more than 150 resources.

Finally, nanOpinion offers an innovative educational programme for schools.

There are differences but they do have a very strong emphasis on communication, dialogue, and outreach both for the public and for schools. Although how a blog in the Guardian science blogs network will help Nanopinion contact ‘hard-to-reach’ target groups is a bit of a mystery to me but perhaps the blog is intended to somehow help them ‘monitor public opinion’? In any event, they sure seem to have a lot of these ‘nano’ dialogues in Europe.

The title of this new Guardian science blog (Small World) reminded me of an old Disney tune, ‘It’s a small world.’ I refuse to embed it here but if you are feeling curious or nostalgic, here’s the link: http://youtu.be/nxvlKp-76io.

Magna Carta for nano?

The more I investigated this Nano Carta news item on Nanowerk, March 14, 2012, the more confused I’ve become. Here’s the easy part,

Part of a Europe-wide debate about the ethical, social and legal questions associated with nanoscience will take place in Bristol on Tuesday [20 March, 2012].

The debate, featuring a group of Bristol University PhD students from the Bristol Centre for Functional Nanomaterials [BCFN], will help form an ethical code for nanotechnology looking at privacy issues, acceptance, human health, access, liability, regulation and control.

Pupils in Years 10 and 11 at St Mary Redcliffe and Temple School will input their own thoughts after learning about nanotechnology – the study of manipulating matter on an atomic and molecular scale – as part of an on-going partnership with the University.

The Nanochannels project is funded by the European Commission and involves 20 teachers from eight countries across the continent, each engaging students through the use of social media such as Facebook, Twitter and live debates. The Guardian newspaper is a partner in the project and is publishing articles on its Nanotechnology World microsite.

Dr Paul Hill, a science teacher at St Mary Redcliffe, won the grant and established the collaboration with the BCFN. Postgraduate students have since been teaching pupils about the theory and practical challenges of researching nanotechnology, with examples from their own PhD research.

Here’s the press release from the University of Bristol announcing the event.

It all got rather confusing when I started reading about the event elsewhere. The Scientix website notes the UK event is part of a larger series, which started in Tel Aviv (no mention of Nano Cartas or any other Cartas),

Nanochannels School Debate series started

Published on: 31/01/2012

Country: United Kingdom

Topic: Nanotechnology,  Project,  Event

Target groups: college students,  general public,  policy makers,  primary school students,  secondary school students,  teachers,  trainee teachers

Two school debates in Tel Aviv, Israel, kicked off the series of live discussions among students, researchers, NGOs, industry and the public on the risks and benefits of the use of nanotechnologies in our everyday life.

The Nano Channels website lists all of the events in this series of live debates which range from Israel (as noted) to the UK, France, Italy, Romania, Turkey, Germany, and Austria.

The topic listed for the March 20,  2012 debate for St. Mary Redcliffe and Temple School is listed as ‘Nano sensors for medical diagnostics’.

I then found an announcement of a March 13, 2012 event in this series held in Italy which does mention the Nano Carta, also on the Scientix website,

Nanochannels Live School Debate – Pavullo nel Frignano

Location: Pavullo nel Frignano

Country: Italy

Type of event: Debate

Organizer: Nanochannels

Project: Nanochannels

Target groups: general public,  industry,  primary school students,  researchers,  secondary school students,  teachers,  trainee teachers

Topic: Nanotechnology,  Education

Language of event: Italian

A live “role play” debate among students, also with participation from researchers, NGOs, the nanotechnology (NT) industry and the general public, who will discuss a specific issue concerning nanotechnologies and their use in our everyday life.

The outcome of the debate will be a “Nanocarta”, a summary of the debate produced by the students, which will be posted on the Nanochannels website and in social media. Over the school year the Nanochannels students will produce press articles with help from professional journalists. The best ones will be co-edited and published by the Nanochannels press partners: The Guardian, El Mundo and Corriere della Sera.

The debate is organised by the Nanochannel project and its partner school in Pavullo nel Frignano (Italy). The project aims to design and undertake a programme of communication on nanotechnology through a variety of media channels and outreach events.

My best guess is that they are focusing on specific topics in the schools so students can get a grasp of some basic nanotechnology concepts before embarking on a debate about larger issues such as ethics and social impacts.

(I have written about the Nanochannels project previously in my June 14, 2011 posting.)

Finally, I thought it would be interesting to get a definition of the Magna Carta (from the Wikipedia essay),

Magna Carta, also called Magna Carta Libertatum, is an English charter, originally issued in the year 1215 and reissued later in the 13th century in modified versions. The later versions excluded the most direct challenges to the monarch’s authority that had been present in the 1215 charter. The charter first passed into law in 1225; the 1297 version, with the long title (originally in Latin) The Great Charter of the Liberties of England, and of the Liberties of the Forest, still remains on the statute books of England and Wales.

The 1215 charter required King John of England to proclaim certain liberties, and accept that his will was not arbitrary, for example by explicitly accepting that no “freeman” (in the sense of non-serf) could be punished except through the law of the land, a right which is still in existence today.

If there’s a Nano Carta and following on the definition of the Magna Carta, whose will is not arbitrary and in what circumstance? Are nanoparticles being ceded rights? I’m being facetious but I hope they do approach these debates in an imaginative way and with questions that might seem ridiculous as that’s often the best way to stimulate new thinking and ideas.

Nanomaterials, nanomedicines and nanodefinitions

I was chatting earlier this week, in the most general way possible, with someone in Ottawa about nanotechnology and regulations.  The individual noted that nanotechnology initiatives in various countries and regions are attaining traction and I think the evidence is in the increased (and heated) discussion/debate about defining nanomaterials. The latest twist in the discussion comes from Alok Jha, a science writer for The Guardian. In his Sept. 6, 2011 article, Nanotechnoglogy world: Nanomedicine offers new cures, he tackles the topic from the nanomedicine perspective.

The EU ObservatoryNano organisation, which supports European policy makers through scientific and economic analysis of nanoscience and nanotechnology developments, produced a report on the ethics of nanotechnology written by Ineke Malsch, director of Malsch TechnoValuation. She says the problem with regulating medical nanotechnology can be how to define a product’s area of application. “The distinction between a medical device and a pharmaceutical is quite fuzzy. …”

How do you regulate a drug-releasing implant, for example? Is Cuschieri’s nano-carrier a pharmaceutical or a medical device? One of [the] key issues, says Malsch, is that there is the lack of common agreement or definition, at the international level, of what a nanoparticle is and what constitutes nanomedicines. “There is continuing discussion about these definitions which will hopefully be resolved before the end of the year.”

Current regulations are more than enough for current technologies, says Malsch, but she adds that this will need to be kept under review. But over-regulating now would also be a mistake. Pre-empting (and trying to pre-regulate) technology that does not yet exist is not a good idea, she says.

This view was backed up by Professor Andrew Maynard, the director of the Risk Science Centre, who says: “With policy-makers looking for clear definitions on which to build ‘nano-regulations’, there is a growing danger of science being pushed aside.”

This (the fuzzy distinction between a pharamaceutical and a medical device) certainly adds a new twist to the debate for me.

Also, I should note that this article’s banner says: Nanotechnology world, in association with Nano Channels.Tim Harper (Cientifica and TNTlog) noticed in an earlier Guardian article on nanotechnology (from his July 7, 2011 posting),

My delight at seeing a sensible piece about “nanotechnology in everyday life” by Colin Stuart (@skyponderer) published in the Guardian Newspaper turned to puzzlement when I noticed that the article was “Paid for by NanoChannels.”

There seems to be some distinction between “paid for” and “in association with,” but I can’t confirm that at this time. Now back to the topic.

In my August 31, 2011 posting, I noted the latest salvo from Hermann Stamm, of the European Commission Joint Research Centre, Institute for Health and Consumer Protection where he reiterated that a hard and fast definition based on size is the best choice. In his Sept. 6, 2011 posting, Andrew where he expands on a concern (i. e. policymakers will formulate a definition not based on scientific data but based on political pressures and/or public relations worries) that I’ve given short shrift. From his Sept. 6, 2011 posting,

And despite policy makers repeatedly stating that any form of nanomaterial regulation should be science-based, I have the sense that they are scrambling to use science to justify a predetermined conclusion – that engineered nanomaterials should be regulated on the basis of a hard and fast definition – rather than using science to guide their actions.Instead, I would suggest that we need to put aside preconceptions of what is important and what is not here, and start by asking how new generations of sophisticated (or advanced) materials interact with biological systems; where these interactions have the potential to cause harm in ways not captured within current regulatory frameworks; and how these frameworks can be adapted or altered to ensure that an increasing number of unusual substances are developed and used as safely as possible – no matter what label or “brand” is applied to them.

He was a little more explicit about what he thinks are the reasons behind this preference for a “hard and fast definition” in his April 15, 2011 posting,

Sadly, it now looks like we are heading toward a situation where the definitions of nanomaterials underpinning regulations will themselves be based on policy, not science.

This scares the life out of me, because it ends up taking evidence off the table when it comes to oversight, and replacing it with assumptions and speculation on what people think is relevant, rather than what actually is – not good for safety, and certainly not good for business.

 

All this got me to thinking about the Interim Policy Statement on Health Canada’s Working Definition for Nanomaterials and the public consultation which ended August 31, 2010.  According to the website, we will be learning the results of the consultation,

Reporting to Canadians

Health Canada will make the results of this consultation available on this Web site.  Health Canada will take further steps to illustrate how the policy statement will be applied in specific contexts.  These steps could include guidance documents for specific products or substances, targeted workshops and postings of answers to frequently asked questions.  The Interim Policy Statement on Health Canada’s Working Definition for Nanomaterials will be updated as comments are received, as the body of scientific evidence increases, and as international norms progress.

If you have any questions, contact nanotechnologies@hc-sc.gc.ca.

Strangely, there’s no mention of the 29 submissions that were made (my May 27, 2011 posting)  or a listing of who made the submissions as was done for Canada’s ‘innovation consultation’ or, more formally, the Review of Federal Support to Research and Development (which started in Oct. 2010 and ended in Feb. 2011 and received some 250 submissions).