APPLICATION OF THE QUARTZ-CRYSTAL MICROBALANCE TO CHARACTERIZE THE INTERACTION OF SOLUTES WITH MODIFIED INTERFACES

被引:15
作者
ROUSH, JA [1 ]
THACKER, DL [1 ]
ANDERSON, MR [1 ]
机构
[1] VIRGINIA POLYTECH INST & STATE UNIV,DEPT CHEM,BLACKSBURG,VA 24061
关键词
D O I
10.1021/la00018a003
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
Piezoelectric quartz crystals, modified by the spontaneous adsorption of either 4-aminothiophenol or octadecanethiol, were utilized to investigate the selective interactions that exist between solutes and the surface modification layer. It is found that the exposed amine functionality of the 4-aminothiophenol monolayer increases the sensitivity of the quartz crystal microbalance to phenols relative to the response found at either a crystal modified with an octadecanethiol monolayer or an unmodified quartz crystal. Protonation of the amino group decreases the sensitivity of the 4-aminothiophenol modified crystal toward the phenol solutes, to a level approximately the same as seen for the octadecanethiol monolayer and the unmodified quartz crystal. The response of the three quartz interfaces studied to structurally similar aniline molecules is nearly the same for each interface and is approximately the same as observed for the phenols at both the octadecanethiol modified interface and the unmodified quartz crystal. These results indicate that a selective interaction between the solute and monolayer leads to increased sensitivity of the quartz crystal microbalance to the solute. For the phenols, the principal mode of interaction at the interface likely involves hydrogen bonding with the basic 4-aminothiophenol. Theoretical fit of the adsorption data to Langmuir isotherms provides a mechanism to determine the free energy of adsorption for the phenols at the 4-aminothiophenol modified quartz crystal. The free energy of adsorption was found to be -16.2 +/- 0.5 kJ/mol for 4-tert-butylphenol, -14.4 +/- 0.6 kJ/mol for 4-isopropylphenol, and -14.8 +/- 0.8 kJ/mol for 4-ethylphenol when interacting with a 4-aminothiophenol modifed surface.
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页码:1642 / 1646
页数:5
相关论文
共 34 条
[1]  
ATKINS PW, 1978, PHYSICAL CHEM, P938
[2]   FORMATION OF MONOLAYER FILMS BY THE SPONTANEOUS ASSEMBLY OF ORGANIC THIOLS FROM SOLUTION ONTO GOLD [J].
BAIN, CD ;
TROUGHTON, EB ;
TAO, YT ;
EVALL, J ;
WHITESIDES, GM ;
NUZZO, RG .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1989, 111 (01) :321-335
[3]   BIFUNCTIONAL MONOMOLECULAR LANGMUIR-BLODGETT-FILMS AT ELECTRODES - ELECTROCHEMISTRY AT SINGLE MOLECULE GATE SITES [J].
BILEWICZ, R ;
MAJDA, M .
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 1991, 113 (14) :5464-5466
[4]   EXPERIMENTAL ASPECTS OF USE OF THE QUARTZ CRYSTAL MICROBALANCE IN SOLUTION [J].
BRUCKENSTEIN, S ;
SHAY, M .
ELECTROCHIMICA ACTA, 1985, 30 (10) :1295-1300
[5]   DETERMINATION OF SURFACE PKA VALUES OF SURFACE-CONFINED MOLECULES DERIVATIZED WITH PH-SENSITIVE PENDANT GROUPS [J].
BRYANT, MA ;
CROOKS, RM .
LANGMUIR, 1993, 9 (02) :385-387
[6]   SYNTHESIS AND CHARACTERIZATION OF SIMPLE SELF-ASSEMBLING, NANOPOROUS MONOLAYER ASSEMBLIES - A NEW STRATEGY FOR MOLECULAR RECOGNITION [J].
CHAILAPAKUL, O ;
CROOKS, RM .
LANGMUIR, 1993, 9 (04) :884-888
[7]   DETERMINATION OF ORGANIC-ACIDS IN DILUTE HYDROCARBON SOLUTION USING POLY(ETHYLENIMINE)-COATED PIEZOELECTRIC-CRYSTALS [J].
CHARLESWORTH, JM .
ANALYTICAL CHEMISTRY, 1990, 62 (01) :76-81
[8]   FREE-ENERGY AND TEMPERATURE-DEPENDENCE OF ELECTRON-TRANSFER AT THE METAL-ELECTROLYTE INTERFACE [J].
CHIDSEY, CED .
SCIENCE, 1991, 251 (4996) :919-922
[9]  
DOBBS DA, 1990, CHEM ENG NEWS, V68, P2
[10]   APPLICATION OF POLARIZATION MODULATION FOURIER-TRANSFORM INFRARED-SPECTROSCOPY FOR THE IN-SITU STUDY OF SPONTANEOUSLY ADSORBED MONOLAYERS [J].
GATIN, M ;
ANDERSON, MR .
VIBRATIONAL SPECTROSCOPY, 1993, 5 (03) :255-261