TAP CHI HOA HOC
DOI: 10.15625/0866-7144.2015-00160
53(4) 445-448 THANG 8 NAM 2015
T 6 N G H O P D I E N H O A V A B A G TiNH
COA N A N O C O M P O Z I T N^N POLY{ANi/o-fol) Vdl FejOj NANO
Tran Van An , Le Xuan Que, Uong Van Vy
Vi$n Ky thudt nhi$t d&i, Vi$n Hdn ldm Khoa hgc vd Cong nghe Vi^t Nam Din Tda sogn 17-12-2014; Chdp nhgn dang 26-8-2015
Abstract
PANi-POT/a-Fe203 (PATF) nanocomposites were synthesized by electrochemical metbod on 316 stainless steel in 0.5 M sulfuric acid solution, with aniline/o-toluidme weight ratios 10/0, 9/1, 8/2, 7/3, and 6/4, nano a-FejO, 2 % by total weight of monomers. The electrochemical synthesis process were studied by cyclic voltammetry technique (CV), scan rate 50 mV/s, step 5 mV and scan range from -0.2 V to 1 V (SCE). PANi-P0T/Fe2O3 nanocomposites were washed with double distilled water to pH = 7, then dried. Properties ofthe nanocomposite were studied using infrared spectroscopy (IR), thermal gravity analysis (TGA), scarming electron microscopy (SEM) and transmission electron microscopy (TEM).
Keywords. Electrochemical, nano composite, poly(ANi/o-Tol), Fe^Os.
fe l.GlCil THIEU
Polyanilin (PANi), poly-o-toluidin (POT) vd poly(anilin-co-o-toluidin) (PAT) Id cac polyme dan dugc ung dyng rgng rai trong nhilu ITnh v\rc nhu:
chdng dn mdn kim loai [1,2, 3], difn tiJ viln thdng [4, 5], son tang hinh [6, 9], xir Iy radi trudng [8] ...
Do cdc polyme ndy cd df ben hda cao, khd ndng dan difn vd chong dn mdn kim logi tdt ...[2]. Tinh chat co-ly-hoa ciia chung phu thuf c chu yeu vdo phuang phdp, dieu kifn chl tgo, ti If monome, chat pha tgp ...[6,8].
Mft so cong trinh khoa hgc ve cdc copolyme tren ca sd polyanilin da dugc cdng bd [2, 11] trcng do cd copolyme ciia anilin (ANi) vdi o-toluidin (o- Tol). Copolyme cua ANi vdi o-ToI cung cd kha nang bao vf chdng an mdn [2, 3, 6], dgc bift khi tgo compozit vdi Fe203.NiO nano [6]. Nanocompozit PANi vdi Ti02 va Sn02 dugc nghien cihi umg dyng trong lmh vge mdi hudng va nang lugng [7]. Ngoai ra dgng hgc va ca chl cua phan iing tdng hgp compozit PANi/TiOa cung da dugc de cgp [11].
Tuy nhien nanocompozit nfn poly (anilin-co-o- toluidin) vdi Fe203 kich thudc nano chua dugc nghien cuu va khao sdt sau cd hf thdng, dgc bift Id irng dyng phuong phdp difn hod dk nghien curu tinh chat chua dugc khai thac hodn thifn. Bdi bao nay nghien cuu qud trinh tong ciia nanocompozit nen poly(ANi/o-Tol) vdi Fe203 (PATF) kich thudc nano bdng phuong phap difn hod vd khao sat mgt sd
tinh chdt cua v^t lifu chf tgo dugc.
2. THU'C NGHIEM 2.1. Hda chat
Cdc hda chat chinh dugc sii dyng trong nghien cihi Id cdc hda chat tinh khilt gom: anilin (Merck), o-toluidin (Merck) dg tinh khilt > 99 %, a-Fe203 (China) mau dd vd kich thudc hgt < 100 nm, H2SO4 (China) dac nong do 95-98 %, nude cat hai ldn, cdn tuyft ddi (Trung Qudc).
2.2. Phuong phap chuan bi mau
Hdn hgp monome ANi, o-Tol cd ti If khdi lugng ANi/o-ToI lan lugt Id: 10/0, 9/1, 8/2, 7/3, 6/4, 0/10 hod tan h-ong dung dich H2SO4 0,5 M. Bdt Fe203 nano cd khii lugng bdng 2 % tdng khdi lugng monome dugc cho vao dung dich tong hgp, khudy diu trong thdi gian 30 phut.
Binh difn hda Id hf gom 3 difn c\rc: difn c\rc so sdnh Id calomen bao hda (SCE), difn cue ddi (CE) bdng platin va difn cue Idm viec (WE) Id thep khdng gi 316 cd difn h'ch bl mgt hieu dyng la I cm^. Difn cue Idm vifc dugc tdy ddu, tay gi, danh bdng bdng gidy nham cd dg nham 1000,1200,1500, sau dd rua sgch bdng nude cdt va say khd bdng con.
Vat lifu nanocompozit sau khi chl tao dugc boc tach khdi difn cyc Idm vifc, ngam, riJa trong nude cdt din pH = 7, say khd d nhift dg 70-80 °C.
TCHH, 53(4), 2015 2 J . Phinmg phap ngbien cihi
Tinh chat va cdu triic ciia vgt Ueu dugc xac dinh bdng cac phuang phap |rfian cyc vdng (CV), phdn tich nhiet (TGA), phd hdng ngogi (IR), hiin vi d i ^ tir quet (SEM) va hien vi difn tir tn^en qua (TEM).
3. KET QUA VA THAO LUAN 3.1. Pho CV tdng bgp nanocompozit J^ATF
Hmh I ^di tiiifu pb6 CV t&ig bgp PANi/Fe203, POT/Fe.Oj va PATF.
Trong hinh I, phd CV tdng hgp PATF (c) biln dang hon so PANi/Fe203 vd P0T/Fe20j. Tren phd
Trdn Van .4n va cgng su CV cua PATF vdi xuat hifn 3 pic gdm 2 pic oxi hoi va 1 pic khii. Khi sd chu k> quet tang difn the pic oxi hod thiit nhat (pal) dich chu\en tir khoang the 02- 035 V den khoang 0.4-0.6 V, pic oxi hod thir nhii ciia PATF djch ve chieu duong ban so v6j nanocompo^ nen PANi \a nen POT. Pic oxi hoa thii 2 (pn) xuat hien trong khoang 0.8-0,95 V. Pic khu (pe) giam ddn tii 0,4 V xuong 0,2 V. Mat do ddng dien tdng hop nanocompozit PATF (c) tang chgm hon so vdi PANiFe;Oi (a). Dieu nay cho tha>
sy cd m$t cua monome o-Tol lam giam qua uinh hinh thanh va phat trien cua mang polyme. Ngu>en nhan Id do phdn tir o-Tol cd nhom the met>I (-CH-.) dvitri ortho gay nen hieu img khdng gian loai I(S;|
Idm can trd su tiep can ciia cac trung tam phan ung.
-c'l 00 0"; e * t * o» 4 ^ 0.0 0 2 01 oe OS li) -C_2 OC 0 2 O.^ 0.£ 0 8 i.5 E (V/SCEJ E {V/SCEI E (V/SCE)
(a) (b) (C) Hmh I: Pho CV tdng hgp nanocompozit PANi/Fe203 (a), POT/Fe:©, (b) \d PANi/POT.Te^O. (c)
3.2. Hinb thai hgc ciia nanocompozit 3.2.1. Hien vi di^n tuquet (SEM)
Anh hiin vi difn tii quet (SEM) ciia compozit PANi/POT chira 2 % nano Fe20j vdi ti If monome ANi/o-Tol khac nhau dugc gidi thif u trong hinh 2.
Quan sdt be mat nanocompyozit bang hien vi dien tu quet (SEM) ta thav be mat vat lieu cd dang mang vd ddm hgt, kich ca cac hat khoang 30-100 nm. Bl mat mau PANi/FciO; (a) kha dong deu, tuy nhien b§
mgt PATP kha rdi rac. Dieu na\ co the giai thich trong qud trinh tdng hop PATF tir hon hgp ANi va o-Tol thi vgt Hfu thu dugc ngoai PATF cdn chiia PANi/FejOj vaPOTTe;03.
(d) (e)
Hmh 2: Anh SEM cua nanocompozit cd ti If monome Ani/o-Tol: 10/0 (a): 9.1 (b): 8/2 (c), 7/3 (d): 6/4 (e)
TCHH, 53(4), 2015
Khi cd FejOs thi khdng cdn ton tai dang mdng hoac ket ty thanh dam md xudt hifn cac hgt compozit [I, 10], tuy nhien sd lugng cac hgt it do ham lugng Fe203 trong ralu chi chilm 2% khoi lugng compozit. Bl mgt compozit PANi/POT/Fe203 khdng ddng deu nhu be mat PANi/Fe203 cd the trong qud trinh copolyme hod cdc monome cd mat oxi sdt (III) hinh thanh hdn hgp cac compozit.
3.2.2. Hien vi di^n tir truyen qua (TEM) Hinh 3 gidi thifu anh TEM ciia nanocompozit PATF cd ti If Ani/o-Tol la 8/2.
Htnh 3 Anh TEM cua nanocompozit PATF Kit qua chyp anh hiin vien difn tii truyen qua cho thdy vgt lifu PATF tong hgp tii ANi, o-Tol va Fe203 cd dgng mang rieng re hoge bam tren be mdt cac hgt Fe203 tgo nen cdc hgt cd kich thudc len tdi 200 nm (hinh 3).
3.3. Phan tich nhiet trgng lugng (TGA) Quan sat gidn dd phan tich nhift hinh 4 cho thay anh hudng khac nhau ciia tl If Ani/o-ToI den tinh chat nhift ciia vgt Ufu. 0 nhift dg 300 "C cac mau vgt lifu bdt ddu phan huy mgnh, din 350 °C cdc mau bi gidm mat 50 % khii lugng, tdi 450 °C ca bdn vgt lifu hi dot chdy het, trong dd mdu M3 va M4 cd dg ben nhift hon ca. Cd su bien ddi khoi lugng khde bift rd rft giura cac mau compozit nen copolyrae vdi mau compozit nln PANi, cdc mdu copolyme cd cac viing khoi lugng khde nhau tuang iing vdi khodng nhift dg: 250-320 °C; 320-380 "C va 380-450 °C. Sy suy gidm khoi lugng theo nhieu nac cho thdy trong qud trinh tong hgp compozit PATF tir hdn hgp monome ANi, o-Tol da hinh thdnh nen hdn hgp compozit nln PANi, POT, PANi/POT vdi Fe203.
Chdt rdn cdn lgi sau khi phan huy vdt lifu cdn tren 2%, cd thi giai thich trong thdnh phan ciia vgt lifu ngodi Fe203 cdn cd the chiia Fe2(S04). Dua vdo gidn do phan tich nhift (hinh 4) ta thdy cdc raau
Tong hgp dien hoa vd dgc tinh...
nanocompozit PATF cd dO ben nhift cao bon" cua PANi/Fe203 tir 10 "C din 70 °C, ddc bift Id mdu M3 vd M4. Rd rang svr cd mat ciia o-Tol lam tang dg bin nhift cila radu.
100 80 60 40 20 0 100
MO.
M1 M 2
.
jRjMS
fcj^, M4
200 300 400 500 600 Nhiet d9(°C)
Hinh 4: Gian dd phdn tich nhift trgng lugng ciia nanocompozit nln PANi (MO) va PAT cd ti If ANi/o-Tol hrong irng: 9/1 (Ml), 8/2 (M2), 7/3 (M3),
6/4 (M4) 3.4. Pho hong ngogi (IR)
Tren pho hong ngoai IR cua nanocompozit PATF, sd sdng khodng 3440 c m ' den 3450 cm'' Id dao dgng hda tri cua nhdm NH2. Khodng 3228 cm'' den 3232 c m ' la dao dOng hda tri ciia amin bdc I.
Trong khoang 2918 den 2926 cm"' Id tdn sd dao dgng hda tri cua nhdm -CH3. Dieu ndy chiing td trong qud trinh tong hgp copolyme thi polyrae thu dugc diu chura nhdm -CH3. Cac pic xuat hifn viing 1442 cm"' din 1638 cm"' tuong iing vdi dao dgng hda tri ciia vdng benzen vd cdc vdng quinoit, tuy nhien cac pic nay thdp ban PANi tinh khilt do sy tac dfng mgnh ciia FeiOa [1]. Ddc bift cdc dinh pic dao dgng bien dgng hifn ro cd sd sdng 6 807 cm"' vd 610 c m ' chiing td cd sy dnh hudng ciia Fe203 trong mdu phan tich. Viing pic 610 cm"' xudt hifn rd rang d§c trung cho dao dgng biln dang cua pha tinh the Fe203 [I]. Trong viJng phd 400-500 cm la dao dgng cua lienkltFe-0[I].
Hinh 5: Pho IR cua PANi/POT/Fc203
TCHH, 53(4), 2015 4 . K E T L U ^
Vdt lifu nanocompozit PANi/POT/Fe203 dugc tong hc^ bang phuang phap difn hda vdi sg cd mgt ciia cac monorae ANi, o-Tol va bgt Fe203 kich thudc nano, phan iing thye hifn trong dung djch H2SO4 0,5 M vdi ti If ANi/o-Tol khac nhau. Monome o-Tol lam eham qud trinh hinh thdnh, phdt trien mang compozh tren difn cyc Idm vifc. Vat lifu nanocompozit PANi/POT/Fe203 che tgo dugc cd be ragt khdng ddng deu, d dang radng hoac hodc ddra hgt Cdc mau nanocompozit PATF cd dg ben nhift cao hon ciia PANi/FejOs tir 10 °C din 70 "C, dgc bift la mdu vdi ti If Ani/o-Tol tuong img la 7/3 vd 6/4.
TAI L1$U THAM KHAO
1. S. Sathjyanarayanan, S. Syed Azim, G. Venkatachari.
Preparation of polyaniline-FejO} composite and its anticorrosion performance. Synthetic Metals, 157(18-20), 751-757 (2007).
2. Evrim Hur, Go-zen Bereket, Yu'cel S_ahin. Anti- corrosive properties of polyaniline, poly (2-toluidine) and poly (aniiine-co-2-toluidine) coatings on stainless steel. Current Applied Physics, 597-604, 7 (2007).
3. A. Benchikh, R. Aitout, L. Makhloufi, L. Benhaddad and B. Saidani. Soluble conducting poly (aniline-co- orthotoluidine) copolymer as corrosion inhibitor for carbon steel in 3 % NaCI solution, Desaluiation, 249(2), 466^74 (2009).
4. Subhash Kondawar, Ritu Mahore, Ajay Dahegaonkar, Shikha Agrawal. Electrical Conductivity of Cadmium Oxide Nanoparticles Embedded Polyaniline Nanocomposites, Advances in
Trdn Van An vd cdngsf Applied Science Research, 2(4), 401-406 (2011). f Borole, D. D.; Kapadi, U. R; Mahulikar, P. p.;
Hundiwale, D. G. Influence of TiOj and SiOj on Electrochemical, Optical and Electrical ComtaOn^
of Polyaniline. Polyfo-toluidine) and Their Co- polymer, Designed Monomers & Polymers, 12(6),
523-532 (2009).
Nguyen Due Nghia, Ngo Trinh Tung. Study on synthesis and anticorrosion properties of pofymr nanocomposites based on super parama^teSc FeiOj'NiO nanoparticle and polyaniline, Syndietic Metals, 159(9-10), 831-834 (2009).
Rajeev Arora, Anupam Srivastav, Utam Kumar Mandal. Polyaniline Based Polymehc Nanocomposite Containing Ti02 and Sn02 for Environmental and Energy Applications, Intemational Journal of Modem Engineering Research (IJMER), 2(4), 2384-2395 (2012).
D. D. Borole, U. R. Kapadi, P. P. Mahulikar and D.
G. Hundiwale. Electrochemical behaviour ^ polyaniline, poly(o-toluidine) and their copolyma in \ organic sulphonic acids, Materials Letters, 58(29), I 3816-3822(2004).
Syed Khasim, S C Raghavendra, M Revanasidda;^
K C Saijan, Mohana Laksbmi and Muhammad Faisal.
Synthesis, characterization and magnetic properties of polyaniline/ y-FciO) composites. Bull. Mater. Sd, 34(7), 1557-1561(2011).
. Y. Wei, W.W. Focke, 0. E. Wnek, A. Ray, A.G.
MacDiarmid. Synthesis and Electrochemistry of Alkyl-ring Substituted Polyaniiines, J. Phys. Chem.
93,495(1989).
La Xuan Qui, Thinh Thi Thu Trang, Nguyen Huy Anh, Mai Thanh Nga, Duong Quang HuAn, Tr^ VSn An, D$ng Dinh Bach. Nghien cuu d0ng hgcj^ung tdng hgp compozit PAni/TiOj, T ^ chl Hfltfhpc, 50(1), 68-73 (2012).
Lien h4: Tran Van An Vifn Ky thuat nhift ddi
Vifn Han lam Khoa hgc va Cdng nghf Vift Nam S6 18, Hoang Quoc Vift, Cau Gi4y, HdNgi
E-raail: [email protected]; Difn thogi: 01692 229 212.
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