Nanomaterialele- domeniu economic de mare interes

Nanomaterialele- domeniu economic de mare interes

Cresterea activitatilor de cercetare in domeniul nanomaterialelor, sustinuta de marile investitii in nanotehnologii realizate de companii statale sau interstatale, vine sa ofere o multitudine de noi proprietati pe care acestea le au. Foarte importanta in domeniu este si depasirea nivelului de laborator la obtinerea nanomaterialelor pentru asigurarea unui volum de productie corespunzator cerintelor comerciale viabile. Activitatile din 343c25d domeniul nanomaterialelor sunt tot mai frecvent supuse si unor analize de etica privind efectele lor in sanatate, mediu si economie in general.

Evolutia de-a dreptul exponentiala a cercetarilor in domeniu este clar redata de evolutia lucrarilor stiintifice publicate. Astfel pentru perioada 1992-2002 in fig 1. se observa acesta tendinta de crestere.

Fig. 1. Evolutia numarului de brevete si publicatii in domeniul    nanomaterialelor

Eforturile financiare, peste 50% din surse guvernamentale, sunt justificate de extraordinarele oportunitati pe care aceste materiale le deschid pentru industriile clasice, in sensul cresterii performantelor produselor, asociat unor avantaje competitive si valori noi create.

Cu toate ca nanotehnologia nu este un termen nou (a fost utilizata inca din anii 1960) a inceput sa fie argumentata ca domeniu in stiinta materialelor si in chimie mai tarziu. In fapt nanoparticule au fost utilizate cu peste 2000 ani inainte(clustere de Au folosite de romani la colorarea vaselor, sau mai tarziu in secolul al X-lea in acelasi scop la ceramice)

O reala schimbare in domeniul utilizarii nanoparticulelor a aparut abia in secolul XX cu producerea carbonului negru prin anii 1940. Descoperirea carbonului C₆₀ (fullerene) in 1985 (ulterior au fost puse in evidenta peste 30 de tipuri de C_2n din aceeasi familie) si a nanotuburilor de carbon in 1991, a dat un stimul real dezvoltarii nanomaterialelor. Evolutia spectaculoasa a puterii calculatoarelor si a modelarii materialelor, cuplata cu avansul semnificativ al tehnicilor de caracterizare a materialelor la scara atomica cum sunt microscopia bazata pe forta atomica (AFM- atomic force microscopy) si cea bazata pe scanarea efectului tunnel (STM- scanning tunneling microscopy), etc. au constituit factori aditionali de dezvoltare a nanomaterialelor pentru o serie de obiective specifice.

1.3.1. Ce sunt nanomaterialele?

Nanostiinta este studiul asupra fenomenelor si manipularii materialelor la scara atomica, moleculara sau macromoleculara, la care proprietatile difera essential de cele de la scara macro.

Nanotehnologiile reprezinta proiectarea, caracterizarea, producerea si utilizarea de structuri, produse finite si sisteme prin controlul formei si dimensiunilor la scara nano.

Nanomaterialele marcheaza limitele dintre nanostiinte si nanotehnologii, asa ca definirea lor este apropiata de a acestora. In principiu, majoritatea cercetatorilor accepta ideea ca nanoparticulele sunt particule materiale care au un diametru de cel mult 250 nm.

Pentru a intelege ce inseamna asta in realitate este suficient sa se recurga la unele date statistice. Spre exemplu, 2 g de nanoparticule de Al cu diametrul mediu de 100 nm, contin suficiente nanoparticule incat sa se poata da fiecarui locuitor al planetei cam 300 000 de particule.

Nanomaterialele acopera, din fericire o arie larga de materiale : polimeri, metale, ceramice. Ele pot avea de asemenea morfologii foarte variate :sfere, fibre, palete, structuri dendritice, tuburi, etc. (vezi fig.2) Tehnicile de producere in laborator si conditiile speciale de sinteza a lor pot determina uneori forme foarte sofisticate pentru nanomateriale (vezi fig 3).

Fig. 2. Aspectul unor nanomateriale (nanoparticole-nanopudre) : (a) Co; (b) oxid de cupru;

(c) ZnO; (d) Ag.

Fig. 3. Nanostructuri de ZnO sintetizate in conditii controlate prin evaporarea termica a pulberilor solide.

1.3.2. De ce prezinta interes nanomaterialele?

Nanomateriale prezinta interes pentru o serie de domenii datorita proprietatilor lor foarte speciale (vezi tab 1)

Tabelul 1 . Domenii de interes pentru nanomateriale

Nanomaterialele la dimensiuni cuprinse intre 1nm si 250nm fac o legatura intre proprietatile atomilor si moleculelor cu cele ale grupurilor de particule materiale. Majoritatea proprietatilor fizice sunt controlate prin fenomene care au un domeniu critic de manifestare la scara nano. Proprietatile electronice care pot fi controlate la aceasta scara prezinta un interes deosebit . In acelasi timp o serie de alte caracteristici cum ar fi cele chimice, mecanice, optice, etc. sunt de un foarte mare interes.

1.3.3. Evolutia in activitatea comerciala cu nanomateriale

Adaugarea de particule in alte matrici de materiale a fost o tehnica uzuala de schimbare a proprietatilor materialelor inca de la inceputul producerii materialelor sintetice. In mod firesc primele particule utilizate in acest scop aveau dimensiuni mai mari decat de ordinal nano.

Prima productie industriala de nanomateriale a inceput in secolul 20 cu producerea carbunelui negru si derivatilor in anii 1940. De-a lungul anilor urmatori au aparut noi companii multinationale. O reala comercializare a productiei de nanoparticole a aparut abia in ultimul deceniu al secolului trecut. O crestere extraordinara s-a resimtit in domeniul produselor electronice si a industriei optoelectronice. Odata cu dezvoltarea tehnologiilor s-a reusit obtinerea de produse din ce in ce mai mici cu componente din ce in ce mai miniaturizate. O evolutie pe parcursul secolului trecut a numarului companiilor producatoare de nanomateriale este redata in fig.4

Marea majoritate a acestor companii au avut ca pornire mici companii initiate pe langa universitati, laboratoare guvernamentale sau antreprenoriale bazate pe finantare guvernamentala. Se estimeaza ca aproape jumatate din companiile producatoare de nanomateriale au inca un asemenea statut. Exista programme de cercetare specifice zonelor mari economice ale lumii in care nanomaterialele se regasesc ca directii prioritare. In Comunitatea Europeana, Programul Cadru 7, are nanomaterialele incadrate ca directie prioritara de cercetare (in clasificarea prezentata in paragraful 1.2.). La acest program Romania a aderat prin structurarea Programului National 2 de cercetare intr-o varianta compatibila cu cea a PC7 european.

Primele tipuri de nanomateriale produse si pietele lor de desfacere sunt prezentate in tabelul 2.

Fig. 4. Evolutia numarului companiilor in domeniul nanomaterialelor

Tabelul 2 Primele tipuri de nanomateriale produse si pietele lor de desfacere

1.3.4. Piata nanomaterialelor

Intrebarea de baza este: care este piata nanomaterialelor ce face acest domeniu atat de atractiv si determina o crestere atat de rapida a numarului companiilor producatoare?

In mod cert exista o asemenea piata. Exista un numar mare de aplicatii in care posibilitatea reprocesarii materialelor existente la scara nano poate oferi noi performante produselor obtinute. Exemplele pot fi multiple, de la sculele de taiere, la care particolele de mici dimensiuni duc la performante sporite, la componentii de lustruire si polizare care utilizeaza particole in jur de 90nm, astfel incat calitatea suprafetelor obtinute e asigurata , respectiv la dispozitivele magnetice la care marea densitate a depunerilor magnetice cu particule foarte fine creste mult capacitatea de stocare a informatiei.

O estimare a productiei diverselor nanomateriale pentru periada actuala si viitoare este redata in tabelul 3.

Taelul 3 Productia globala estimata pentru diferite tipuri de nanomateriale (estimare realizata in perioada 2003-2004)⁸

Apar mereu noi aplicatii ale nanomaterialelor si produse care seduc atentia atat a producatorilor cat si a utilizatorilor. Noile produse optoelectronice, produsele de mici dimensiuni mult mai eficiente energetic, nanotubirile de carbon cu extraordinarele lor aplicatii, atrag tot mai multe fonduri in cercetare si productie. Din acest motiv au aparut si apar companii care pot sa produca asemenea materiale in cantitati de ordinul sutelor de tone anual. Cifrele de afaceri care se deruleaza in domeniu de ordinul sutelor de milioane de dolari la nivelul anilor 2004-2005 se estimeaza sa ajunga la zeci de miliarde in 2010. Aceasta se datoreaza in special aplicatiilor nelimitate pe care aceste nmateriale si le regasesc actual, dar mai ales in perspectiva tehnologiilor si produselor viitoare (vezi tabelul 4)

Tabelul 4. Aplicatii actuale si viitoare ale nanomaterialelor.

1.3.5. Viitorul nanomaterialelor si a companiilor care le produc

The use of nanoparticles is set to escalate and the market has the potential to increase dramatically over the next ten years, as more uses for these materials are developed and commercialized.

A major impact will be in the medical and pharmaceutical markets as new treatments using nanoparticles obtain licenses for use. But there are many other applications where the time to market is considerably less than the pharmaceutical market, particularly in consumer goods. However, there are still many challenges for nanomaterials companies to overcome before the potential is fully realized. These include:

• Health, safety, and environment – the profile of nanotechnology has increased in recent years with a focus on the potential long-term effects of nanotechnology and, more immediately, nanomaterials on people and the environment^{8, 44, 45, 46, 47, 48, 49, 50 and 51}. As with any high-profile technology, questions will be asked, but some nanomaterials have been with us for many years without causing concern. However, it is very important to the success of this industry that any concerns are addressed. The key aspect is: are there any detrimental effects over and above those already identified purely from the fact that these materials are in the nano form? It is also highly unlikely that nanomaterials will be used without being incorporated into some other media, such as a composite or liquid. Research is underway into the effects of nanomaterials, and it is difficult to draw any firm conclusions to date, but there is evidence that there may be positive benefits from these types of material both for humans and the environment^{50 and 52}.

Bibliogfrafie

1 The Nanotech Report 2004 Investment Overview and Market Research for Nanotechnology (3^rd edition) Lux Research Inc., New York 2004 www.luxresearchinc.com/TNR2004.

2 R.A. Bleeker et al., Materials Today 7 (2004) (2), p. 41.

3 B. Corish, CIPA Congress – Nanotechnology Workshop, Thomson Scientific, London (2003).

4 www.thebritishmuseum.ac.uk/.

5 D. Erhardt, Nat. Mater. 2 (2003), p. 509.

H.W. Kroto et al., Nature 318 (1985), p. 162.

7 S. Iijima, Nature 354 (1991), p. 56.

8 Nanoscience and nanotechnologies: opportunities and uncertainties, The Royal Society & The Royal Academy of Engineering, London, (2004).

9 L.W. Zhong, Materials Today 7 (2004) (6), p. 26.

10 J.S. Murday, AMPTIAC Newsletter 6 (2002) (1), p. 5.

11 P. Moriarty, Rep. Prog. Phys. 64 (2001), p. 297.

12 The MicroJetReactor for Producing Nanoparticles, Synthesechemie GmbH, home.t-online.de/home/penth/ebesch.htm.

13 Kava Technology (2004), www.kavatechnology.com/index.html.

14 E.L. Mayes, J. Mag. Soc. Jap. 26 (2002) (8), p. 932.

15 K.L. Choy, Process principles and applications of novel and cost-effective ESAVD based methods, Innovative Processing of Films and Nanocrystalline Powders, World Scientific Publishing, Singapore (2002).

16 M.S. Dresselhaus et al., Carbon nanotubes – Synthesis, Structure, Properties and Applications, Springer-Verlag, Berlin/Heidelberg (2001).

17 P. Holister and T.E. Harper, The Nanotechnology Opportunity Report, CMP Cient'fica, Madrid (2002).

18 A. Jones and M. Mitchell, Nanotechnology: Commercial Opportunity, Evolution Capital Ltd, London (2001).

19 Rittner, M., Opportunities in Nanostructured Materials, GB-201, Business Communications Co. Inc., Norwalk, CT, USA, 2001.

20 D.K. Rodham et al., A Technology Road Map for Colloid and Interface Science in the UK, IMPACT Faraday Partnership, Reading, UK (2003).

21 Technology Alert – Nanotechnology, Institute of Nanomaterials, Glasgow, 2001.

22 Opportunities for Industry in the Applications of Nanotechnology, DTI Foresight Materials Panel Report, London, 2000.

23 Nanophase materials innovative developments mould a thriving industry, D212, Frost & Sullivan, New York, 2001.

24 Kobayashi, N., Nanotechnology, Hitachi Research Institute Report, Toyo Keizai Shimpo-sha, Tokyo, 2001.

25 Nanotechnologies, Technanogy merge assets, Small Times (14 April 2004) www.smalltimes.com/document_display.cfm?document_id=7733.

26 Konarka acquires Siemens' organic photovoltaic research activities, www.konarkatech.com/.

27 Degussa Investing €25 Million in Advanced Nanomaterials, Degussa Press release, (27 February 2003).

P. Short, From small things, big things will come, Chemical and Engineering News 82 (2004) (28), p. 17.

29 Nanophase technologies announces exclusive partnership with and $10m investment by Altana Chemie AG (25 March 2004) www.nanophase.com/investor_relations/press.asp?PRESS_RELEASES_ID=87.

Y. Wang et al., Appl. Phys. Lett. 85 (2004), p. 2607.

31 Fried, J., Japan Sees Nanotech as Key to Rebuilding its Economy, Small Times (7 Jan 2002) www.smalltimes.com/document_display.cfm?document_id=2843.

32 Third European Report on Science & Technology Indicators EUR 20025 European Commission, Brussels, 2003.

33 Dunn, S., and Whatmore, R. W., Nanotechnology advances in Europe, Working Paper STOA 108 EN, European Commission, Brussels, 2002.

34 The Nanotech Report 2003, Investment Overview and Market Research for Nanotechnology (Vol II), Lux Capital, New York, 2003.

35 Institute for Soldier Nanotechnologies, Massachusetts Institute of Technology, https://web.mit.edu/isn.

36 Nanotechnology information sheet, Ministry of Defence, 2001, www.mod.uk/linked_files/nanotech.pdf.

37 W. Babcock, AMPTIAC Newsletter 6 (2002) (1), p. 1.

38 D. Chung, Nanoparticles have health benefits too New Scientist 179 (2003) (2410), p. 1616.

39 L. Kabacoff, AMPTIAC Newsletter 6 (2002) (1), p. 37.

40 P. Holister, Nanotech – the tiny revolution, CMP Cientifica, Madrid (2002).

41 D. Draper, World Sports Activewear (Spring 2003), p. 16.

42 D. Graham-Rowe, Bad breaks fixed fast by bone ‘printer’, New Scientist 178 (2003) (2400), p. 20.

43 D. Graham-Rowe, Nano-coated implants cut MRI scan dangers, New Scientist 179 (2003) (2402), p. 13.

44 Nanotechnologies: a preliminary risk analysis, based on a workshop on 1–2 March 2004 by the Health and Consumer Protection Directorate General of the European Commission, Brussels, 2004 https://europa.eu.int/.

45 Malsch, I., (ed.), Benefits, Risks, Ethical, Legal and Social Aspects of Nanotechnology, NanoForum, June 2004, www.nanoforum.org.

46 Luther, W., (ed.), Industrial applications of nanomaterials – chances and risks, VDI Technologiezentrum GmbH under EU Nanosafe project.

47 Hett, A., Nanotechnology, Small matter, many unknowns, Swiss Reinsurance Company, 2004.

48 S. Wood et al., The Social and Economic Challenges of Nanotechnology, EPSRC, Swindon, UK (2003).

49 A.H. Arnall, Future Technologies, Today's Choices – Nanotechnology, Artificial Intelligence and Robotics; A Technical, political and institutional map of emerging technologies, Greenpeace Environmental Trust, London (2003).

W-X. Zhang and T. Masciangioli, Environ. Sci. Technol. 37 (2003) (5), p. 102A.

51 J. Ryan, Physics World 17 (2004) (8), p. 16.

52 Rzigalinski, B., and Seal, S., Science Daily (14 August 2003) www.sciencedaily.com/.