TAP CHI HOA HQC T, 50(4) 425-428 THANG 8 NAM 2012
DIEU CHE DUNG DjCH SAT NANO BANG QUA TRINH HOA TAN ANOT DIEN AP CAO
IVguyen Dire Hiing*, Do Thanh Tuan Vi^n Hda hgc - Vgt li^u. Vi^n Khoa hgc vd Cdng ngh^ Quan su
Din Tda soan 14-11-2011 Abstract
Iron nano melal solution is prepared from anodic dissolution process wiih ultra-high DC voltage. The size and shape of iron nanoparticles detemiined by TEM images and particle size distribution on the device LA-950 Laser Scattering Particle Distribution Analyzer V2. The concentration of nano-iron solution was determined by the analytical methods AAS atomic absorption specUometry and Faraday's law. The difference in concentration of both methods demonstrated outside the anodic dissolution process has created the water electrolysis to form H2 and O2 gases and heating ihe solution.
Keywords: Metal nanosolution, nano-iron, soluble anode process, high voltage.
1. M(iiDAU
Nano sat dugc nghien cuu chii yeu de che tao vat lieu xiic tdc [1], vgt lieu tir [2] va ngudn dien [3].
Khdc vdi cdc dimg djch nano kim loai khd ben nhu vang, bgc. ddng dang ngay cang dugc chu y su dung trong nhieu linh vuc nhu cdng nghe gdm sir, dien tii va dac bipt Id y hgc [4], nano sat tuong ddi de bj oxihda [5] nen thudng su dung trang thai ket hgp.
Ngay nay bdt sat micro-nano kim loai hda trj khdng cung dang dugc nghien cuu su dung rdng rai de xir ly d nhiem mdi trudng [6-8].
Nhieu ky thuat che tao dung djch hat nano kim logi [9-11] nhu vgt ly, hda hgc nhung phuong phap dien hda [12-14] td ra cd nhieu Igi the ve sy don gian vl thilt bi va cdng nghe, dac bipt dugc thyc hien d nhiet do va dp suat thudng. Phuong phdp hda tan andt sat kim logi bang dien dp cao vdi nhung dieu kien phdn iing dien eye chgn thich hgp chiing ta cd the tgo dugc dung dich nano sat dat ndng dp cd gia trj su dung.
2. PHl/ONG PHAP NGHIEN CUtJ
Dien eye andt vd catdt sdt dgng try 01xhl 6x150 mm dugc diic bpc kin xung quanh bang nhya epoxy 02xh2 = 18x120 mm tgo dien tich tiet dipn dien eye: 29,1834 mm^. Vat lieu dipn eye dugc chpn la CT38 cd thdnh phan C: 6,14-0,22%, Si: 0,05- 0,17%, Mn: 0,4-0,65%, Ni, Cu, Cr: < 0,3%, P, S <
0,04% [15]. Binh phdn iing di6n hda dugc chi tao tir dng nhya PVC thanh 2 lop vdi kich, thudc lap thd nhdt chiia nude cdt 2 Idn: 0 3 x h3 = 120x1000 mm
vd Idp thir 2 dl chira nude lam mat: 04xh4 = 200x1200 mm. Binh phdn iing dugc Idp thdng dirng vdi andt sdt dugc lap phia tren cdn catot Idp phia dudi. Ngudn cung cdp dien mot chilu la chinh luu cao dp 25 kV/250 mA cd ddng hd hien thj sd gid trj the va ddng. Dien ap va ddng ra mot chilu dugc dieu khien vd cdp vdi chi dp bdo hiem ty dpng khi qua ddng vd qua the. Chi do phan irng dugc nghien cuu la dn dp va dn ddng. Kich thudc va hinh dang hat nano dugc xac djnh bang kinh hien vi dien tir truyen qua (TEM) fren thiet bi JEOL JEM-IOIO tai Phong hiln vi dien tir, Vien Ve sinh dich le Paster. Phan bo cd hat dugc phan tich bang thiet bj LA-950V2 Laser Scattenng Particle Distribution Analyzer cua hang HORIBA tai Vien Hda hoc - Vat lieu. Thdnh phan dung dich dugc xac djnh bdng cdc phuang phap phd hap thy nguyen tii cd dp chinh xac den 2% trong khoang nong dp 0,K0,005 mg/ml tai Vien Hda hpc.
Vien Khoa hpc va Cdng nghe (KH&CN) Vipt Nam tr6n thilt bj Perkin-Elmer AAS-3300. Qua trinh hda tan andt sdt (hirih 1) bi tac dgng bdi mat dp ddng nen ciing cd the xac dinh dugc ndng dp ciia kim loai hoa tan theo djnh lugt Faraday.
m Alt ^„
c=—=— (1) V nF
Trong do: m (mg) la lugng kim logi dugc gidi phdng d dipn cue tinh tir djnh lugt Faraday, V (lit) la the tich nude cdt cua binh phdn irng, A (g) la khdi lugng mol cua kim logi, I (mA) Id cudng dg ddng andt, t (giay) la thdi gian dipn phan,,F la hang sd Faraday bang 96.500 va n la sd dipn tu cho va nhgn.
TCHH.T, 50(4),2012
Hinh 1: An6t Fe bj hda tan Do qud trinh hda tan anot ciia di^n eye kim logi 1dm gidm trpng lugng n6n n6ng dg dung djch thu dugc ciing cd thi tinh tir sy hao hyt trgng lugng ciia an6t bdng cdn dipn tir EG 220-3 NM.
3. KET QUA VA T H A O LUAN
Hinh 1 cho thay anot sdt bj hda tan sau khi thyc hipn qud trinh hda tan anot cdn catot sdt van khong bl thay ddi. Hinh 2 trinh bdy kit qud chyp dnh TEM vd phdn tich phdn bo cd hgt ciia dung djch kim logi
Nguyin Dtk: Hung vd cgngstfi sdt thu dugc tir qud trinh hda tan an6t on ap tgi 14 kV vd che dg 6n ddng tgi 130 mA. Anh TEM hinh 2a vd 2b cho thSy hgt nano sdt thu dugc cd dgng hinh trg trdn vd cd kich thudc dudng kinh hinh tru dIu nhd hon 100 nm song chilu ddi ciia hgt hinh tr^i khodng hon 100 nm= Tuy nhiSn dnh TEM cung cho ,"
th^y cdc hgt nano sdt dIu cd xu hudng kit dinh vdo nhau tgo thdnh ddm Idn nSn khi xdc djnh dudng phdn bo cd hgt sS nh$n dugc nhilu hgt Idn hon 100 nm. Th§t vfly, hinh 2c, vd 2d cho th^y vimg phdn b6 cd hgt khd rOng bdt 6ku tir 50-80 nm cho din 500- 1.000 nm vd eye dgi cua dudng phan bo cd hgt khodng 200-250 nm cho cd 2 trudng hgp hda tan an6t sdt 6n dp vd on ddng. Song vdi che dp ht\ dp cdn cd cdc dinh cua cdc phdn b6 d kich thudc Vm ban cd 800 pm vd thdm chf din 2.500 pm. Dieu d6 rat cd the cdc hgt cd khd ndng dinh kit ddm Idn khd ben nen lye sieu dm cua thilt bj phan tich cd hgt chua dii <ih chia tdch vd phdn bo deu trong moi trudng phdn tich. M9t khdc dnh TEM cung cho dily tgi nhii-ng dilm kit dinh cua cdc hgt dg d$m cua dnh ch^p cao hon cdc hgt rieng le.
Hinh 2: Anh TEM (a, b) vd Phdn bo cd hgt (c, d) cQa dung djch nano thu dugc ti^ che dg hda tan anot dn dp (a. c) va che dg hda tan anot 6n ddng (b, d)
TCHH, T. 50(4), 2012
Ket qua ve dac diem cua qud trinh hda tan an6t cua dipn eye sat tai che dd dn dp vdi cac di^n dp, cdc khoang each dien eye giii'a andt - catot vd thdi gian phdn ung khdc nhau dugc trinh bdy tai bdng 1. Bang 1 cho thdy vdi dipn dp cao tir 13,5 kV den 16 kV phan ung hda tan andt sdt xay ra vdi cdc khodng each dipn eye andt va caot tir 425 mm den 695 mm lam cho diSn eye andt bj dn mdn vdi thdi gian phdn ung tir 8 din 25 phut. Vdi dipn dp ciia phdn ii-ng nhd chi 12,5 kV thi dii thdi gian keo ddi din 25 phiit
Diiu chi dung dich sdt nano bdng...
vd khoang cdch giifa 2 dipn eye chi 425 mm, di6n eye anot cung khdng bj hda tan. Dieu dd chiing td gid tri dipn dp cua dipn the cao phai du ngudng mdi cd tac dpng din qua trinh hda tan anot ciia sdt.
Khi gia trj dipn ap chua den ngudng thi khodng cdch va thdi gian se khdng cd tac dpng den qud trinh hda tan sdt anot. So vdi kim logi khdc nhu nhdm [14] dipn dp ngudng hda tan kim logi cao hon din 1.000 V.
Bang 7: Dac diem an6t s5t 6 che dp on ap 14k V, v6i th6fi gian vi khoing Ki hi?u
F e - 1 . 8 F e - 1 . 9 F e - l . I F e - 1 . 2 F e - 1 . 3 F e - 1 . 4 F e - 1 . 5 F e - 1 . 6 F e - 1 . 7 F e - l . I l Fe-1.12
Di?n ap, kV 16 15,0
14 14 14 14 14 14 14 13,5 12,5
D (anot-catot, mm) 605 560 560 515 470 425 605 650 695 470 425
t, min 9 12 15 13 S 9 18 20 25 8 25
each khac nhau D^c diem anot
Bi an m6n B) Sn mon Bi 3n mon Bi an mon Bi an mon B| an mon B| an mon Bj an mon Bi an mon Bi an mon Khong an mon Ciing tuong ty, phdn iing hda tan andt d che dg
dn ddng vdi khodng cdch cdc dipn eye tir 425 mm den 605 mm deu nhgn thdy andt bj an mdn (bdng 2), song lugng an mdn khdng nhieu nen khd ti'nh dugc nong dp theo phuang phdp tdn hao trpng lugng andt.
Ket qua bdng 1 vd 2 deu cho thdy cac khodng
each giii'a 2 dipn cue cdng gan thi thdi gian dien phan cdng ngan vi dipn dp ciia phdn img tang nhanh de dgt den gid trj an toan qua ap ciia thiet bj nen bj ngat mgch phan ung. Trong trudng hgp nay mudn tang lugng chat hda tan cd the lap lai phdn iing nhilu Idn.
Bdng 2: Dac dilm andt sdt d chi do dn ddng 140 mA vdi thai gian va khodng each khac nhau Ki hieu
F e - 2 . 1 F e - 2 . 2 F e - 2 . 3 F e - 2 . 4 F e - 2 . 5
D (anot-catot, mm) 605 560 515 470 425
t, min 30 29 23 18 12
Dac diem anot Bi an mon Bi an mon Bi an mon Bi an mon Bi an mon Bang 3 trinh bay kit qud xac djnh ndng dp nano
sdt trong dung djch thu dugc sau phdn iing theo phuong phdp: phdn tich AAS, va tinh theo djnh lugt Faraday Mt ddng an mdn. Kit qud tir bdng 3 cho thay, gia trj ndng dg ciia sat dugc xdc dinh theo phuang phap AAS rdt nhd, cdn gid trj tinh dugc tir ddng an mdn theo djnh lu§t Faraday Idn hon tu 6 din ban 18 Idn. Hi^u sudt ciia qua trinh hda tan andt tinh dugc cung thap, chi dgt tur 5,54% den 14,1%,
chi bdng 1/2 so vdi qua trinh hda tan nhdm theo [14]. Dieu do rat cd the do sat kem hogt dgng ban nhdm mgt dii bl mat nhdm de thy dpng hon sat.
Nhu vgy, tir hipu sudt phdn iing ciio thay gan 86 den gan 95% lugng dipn d dien dp cao dugc chuyen thanh nhipt Idm ndng dung djch va m^t phdn de thyc hipn phdn ijmg dipn phan nude tgo kbi hidro d catot va oxi d anot. Vi vay ca che ciia phan ung dipn hda hda tan anot dl tao thdnh dung d\A kim loai kich
TCHH, T. 50(4), 2012 Nguyin Due Hung yd cgnga{
thudc nand tgi dipn dp cao cdn dang Id vAn dl thii vj sinh ra trfin di§n eye din qud trinh tgo hgt nano kim can phai tilp tyc nghien ciru vl tdc dyng ciia cdc khi logi.
Bdng 3: Ket qud phan tich hdm lugng cic tiiaii dung djch sdt theo AAS vd tinh theo Faraday
STT 1 2 3 4 5
Ki hi^u mau Fe-2.1 Fe - 2.2 Fe - 2.3 Fe - 2.4 Fe - 2.5
Theo AA.S C,-„ mn/l
0,27 0,27 0,54 0,54 0,27
Tinh theo Faraday C,,„ mg/l
4,87 3,19 4,50 3,83 3,96
HS, % 5,54 8,46 12,00 14,10 6,82 4. KET LUAN
Qud trinh hda lan anot ciia dipn eye sdt CT38 trong nude cat 2 Ian xay ra d dipn dp cao hon 13.5 kV d ca che dg phan irng on dp vd on ddng cho eye dgi dudng phdn bo kich thudc hgt cd 200-250 nm va dnh TEM nhd hon 100 nm. Dgng hgt sdt nand kim logi chii ylu hinh try cau. Nong dg nand sdt kim logi theo che dp dn ddng thu dugc cao hon chi dp on dp va dgt din 0,54 mg/l do cd the duy tri thdi gian phdn irng dipn eye Idu ban. Nong dp dung djch nand sdt kim logi tinh tir ddng dn mdn theo djnh lugt Faraday Idn ban den gap 6-18 Idn nong dp nano sdt xdc djnh theo phuang phap AAS. Nhu vgy tren anot ngodi phdn ung hda tan sat cdn cd phdn ung thoai khi vd CO che tgo hat nand sat tgi dien dp cao sS cd su tham gia ciia khi dugc tgo thdnh tren dipn eye catot.
Lffi cam on: Tdc gid xin cam on quy NAFOSTED dd tao dieu ki^n de thuc hi^n de tdi, md so 104-2010.33.
TAI LIEU THAM KHAO
1. C. N. R. Rao, A. Miiller, A. K. Chectham.
Nanomaterials Chemistry', Wiley-VCH Verlag GmbH & Co. KGaA (2007).
2 B, Bhushan. Handbook of Nanotechnoiogy, Springer Verlag, Beriin (2004).
3. B. E. Conway. Electrochemical Supercapaitors, Kluwer-Plenum, New-York (1999).
4. C. .zi S. R. Kumar, J. Hormcs, L - Lcuschncr.
Nanofabrication towards biomedical applications - Techniques, tools, applications, and impact, Freiburg. Germany, WILEY-VCH Verlag GmbH
& Co. KGaA, Wemheim (2005).
5. C. Noubactep, Characterizing the discoloration of
methylene blue in Fe /H2O systems, Joumal of Hazardous Materials, 166. 79-87 (2009).
Lc Quoc Trung, Nguyen Due Hung. Nguyen Hon Nam, Tran Van Chung, I. Francis Cheng. OxidahM of 2,4.6-Trinitroresorctne Using Zero-Valent Inm Asian Joumal of Chemistry, 22(4), 32OO-3206 (2010).
Christina R, Keenan, David L. Sedlak. Factm affecting the yeild of oxidants from the reaction tf nanoparticulate zero-valent iron and oxygm.
Environment Science Technology. 42. 1262-1247 (2008).
Le Qu6c Trung. Nghien cuu dgng hgc qua tiinh Uw bang kim logi hda tri khong (sdt. kim) ddi vdi 2,4,6 tritoluen vd 2.4.6 trimtroresocxin, Ludn dn Tilnil Hoa hpc. Vi^n KH&CNQS (2011).
C. N. R. Rao, A. Mullcr, A. K. Cbeelham. Tia Chemistry' of Nanomaterials - Synthesis. Propertia and Applications, Wiley - VCH Verlag GmbH & Cn.
KGaA (2004).
. G. Schmid el al.
Technikfolgenbeurteilung-Nanoiechnology, Spiiaga Verlag. Berlin Heidelberg (2006).
11. Nguyin Dire Hung. Chi tgo vgt li^u nano kim lofi
P-
bang cdng ngh^ difn hod vd khd ndng ung dt/t^, T«i chi KT & TB, 10(97). 38-42 (2008).
12. C Alkire. D. M. Kolb, J. Kipkowski, P. N. Ros.
Advances in Electrocchemical Science and Engineering, Wiley-VCH Verlag GmbH&Co. KGaA (2008).
13 J. Locn. Electrochemical Nanotechnoiogy, Vlikf- VCH Veriag GmbH & Co. KGaA (1998).
14. Nguyen Diic Himg, NguySn Minh Thuy, Ddo TTianh Tuan. Dung djch nhdm nano diiu chi bdng qua triiA hda tan andt di4n dp cao, Tgp chi Nghien ciiu KH&CNQS, 8(14), 97-101 (2011).
15. TCVN 1651-85.
Lien h^: Nguyin Dtrc Hung
Vipn Hda hpc - V§t lipu, Vipn Khoa hgc va Cong nghp Quan sy 17 Hoang Sdm, Cau Giay, Hd Ngi
Email: [email protected].
