Nghiên cứu động học quá trình Polyme hóa điện hóa anilin trong H2SO4 có mặt FeSO4

TAP CHI HOA HOC T. 49(6) 743-747 THANG 12 NAM 2011

NGHIEN CLTU DONG HOC QUA TRJNH

POLYME HOA DIEN HOA ANILIN TRONG H2SO4 CO MAT FeS04

Dirong Quang Huan' ^ Lc Xuan Qu£'", Hoang Van ^oan^ Ngd Thj Dung^

Nguyen Huy Anh\ Mai Thanh Nga\ Tran Van An''^

' Vien Ky thugt Nhiet ddi. Vien Khoa hpc vd Cdng nghi Vi^t Nam

' Tnrdng Dgi hpc Suphgm Hd Npi 2

' Vien Hod hpc Cdng nghi('p Vi^l Nam

^Trudng Bai hpc Suphgm Hd Ngi

'Dgi hpc Sirphgm Thdi Nguyen

Den Tda so9n 26-7-2011

Abstract

Polyaniline (PANi) films have been electrochemically synthesized on stainless steel 3 I6L in HjSO,, solution using

cyclic voltammetry. There are three oxidation regions on the CV curve FeS04 salt, added in the solution, affected

strongly the synthesis process. Kinetics of the synthesis was studied basing on variation of the total anodic polarisation

charges, redox peaks parameters, and derivation dJ/dE for the entire CV potential ranges, in regard to the FeS04 salt

concentration. It was found that the concentration ratio [Fe^"']/[ANi] and number of CV cycles modified strongly

kinetics of the polymerization.

I.GIOI THIEU

Polyanilin (PANi) dugc H. Letheby tdng hgp

diu tien vio nim 1862 bang phuang phip dien hda.

Den nam 1910, lin diu tien PANi dugc tong hgp

bing phuang phip hda hgc. Nhung chi gin day

PANi mdi dugc cic nhi khoa hpc quan tam sau khi

phit hien ra khi ning din dien cao cua nd. Rat nhieu

cdng trinh nghien cuu tdng hgp PANi vi compozit

cua PANi vdi cic oxit kim loai nhu TiO:, Fe203, lim

ting khi ning irng dung thuc te, dac biet la khi nang

chdng in mdn kim loai va xu ly mdi trudng [1-3].

FeS04 dugc sir dung trong nghien ciru che tao

ming PANi bien tinh, vi cd nhiJng hieu irng di?n

hda nhat dinh ddi vdi tinh chit dien hda ciia ming

polyme din dien [4-6]. Qui trinh oxi hoa khu cua

cap redox Fe^VFe'* dugc ghi nhin ngay trong qua

trinh tong hgp PANi [4, 5, 7].

Co che ciia qua trinh polyme hda dien hda anilin

(ANj) dugc quan tam nghien ciru tir nhirng nim 90

cua the ki trudc vi dugc xic dinh la co che cation -

gdc [8-12]. Tuy nhien, ddng hgc ciia qui trinh

polyme hda dien hda anilin hien chua dugc nghien

cuu chi tiet. Bai viSt niy gidi thieu phuang phap xic

djnh dpng hgc qui trinh polyme hda dien hoi anilin

dua vio phd phan cue tuan hoin da chu ky (cyclic

voltammetry - CV) vi inh hudng ciia FeS04 d^n

ddng hgc qui trinh niy.

2. THUC NGHIEM

Cic hoi chat dugc sir dung li: monome anilin

(Guangzhou Jinhuada Chemical > 99,5%), H2SO4

98% vi FeS04.7H20 d6u cd do tinh khilt PA.

Dien cue lim viec (working electrode - WE) li

thep khdng gi dien tich 1 cm^. Dien cue dugc dinh

bdng bang giiy nhim vi rira sach bang nudc cat, cdn

ky thuat nhim tao be mat dien cue cd do bdng cao

vi khi ning bim dinh tdt. Phii vecni tren dien cue,

chi de lai dien tich tiep xiic vdi mdi trudng (1 cm^).

Thiet bi dien hoi li miy AUTOLAB PG.STAT

30 (Eco Chemie B V. Utrecht, the Netherlands) vdi

chuang trinh ghi vi xu ly sd lieu tu dpng GPES 4.9

for Windows gii sin trong miy tinh.

Phuang phip CV dugc ip dung de nghien cuu

tdng hgp ming PANi, dien the phin cue dugc quet

trong khoang -0,2 V den 0,8 V vdi tdc dp quet 20 -

100 mV/s. Sd chu ky quet phu thypc vio yeu cau

ciia phep do, cd the tir mpt vai den hing tram chu ky.

Chi tiet ve phuang phip thi nghiem da dugc gidi

thieu d mgt sd bii dang trudc day [3,4].

PANi dugc tdng hgp bang phuang phip CV

trong mdi trudng H2SO4 1 M vdi ndng do ANi

khdng ddi 5 ml/100 ml va dung dich FeS04 d cac

ndng dp khic nhau (bing 1). Sau khi hda tan ANi

vio dung djch axit mdi cho FeS04 vdi ti 1? ndng dp

djnh trudc vao he do. Dung dich dugc do trong

ngiy, khdng de qui 24 gid.