Raman spectroscopic investigation of the single-monolayer Langmuir-Blodgett film of C16NaphOH and C10AzoNaphC4N-SDS.
Raman spectra were measured for Langmuir-Blodgett (LB) films of C(16)NaphOH and C(10)AzoNaphC(4)N-SDS on Calcium Fluorite substrate for the first time. In order to find out favorable excitation condition, Raman spectra of the single and multi-monolayer LB films excited at different lines at 244, 514, 633 and 778 nm are recorded and compared in the present study. Raman spectrum of the monolayer LB film of C(16)NaphOH excited by 244 nm demonstrate that excellent signal to noise is achieved even for one monolayer LB film with an extremely short integrating time as 60 s because of being resonantly enhanced, while no meaningful spectra were recorded under the same condition for the monolayer LB film of C(10)AzoNaphC(4)N-SDS because of burning. Using a HeNe 633 nm excitation the problem with strong substrate fluorescence was partially solved, since under these conditions this fluorescence is mainly outside the fingerprint region of the LB film molecules (1000-2000 cm(-1)). Therefore by using the HeNe laser excitation, Raman spectra with high signal to noise ratio of LB films of C(16)NaphOH were collected and shown in this paper. These findings stress again the necessity to define an appropriate Raman system for this special application of LB film diagnosis.
Wu
Yuqing
Y
Key Laboratory for Supramolecular Structure and Material of the Ministry of Education, Jilin University, 130023, Changchun, People's Republic of China.
Zhao
Bing
B
Xu
Weiqing
W
Li
Guowen
G
Li
Bofu
B
D000473:Alkanes / Q000737:chemistry*; D001391:Azo Compounds / Q000737:chemistry*; D002124:Calcium Fluoride / Q000494:pharmacology; D002244:Carbon / Q000737:chemistry; D008956:Models, Chemical; D009281:Naphthalenes / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D012967:Sodium Dodecyl Sulfate / Q000031:analogs & derivatives / Q000737:chemistry*; D013059:Spectrum Analysis, Raman / Q000379:methods*
D000473:Alkanes; D001391:Azo Compounds; C479864:C(10)AzoNaphC(4)N-SDS cpd; C479863:C(16)NaphOH cpd; D009281:Naphthalenes; D011108:Polymers; D012967:Sodium Dodecyl Sulfate; D002244:Carbon; D002124:Calcium Fluoride