Per-6-O-(tert-butyldimethylsilyl)cyclodextrins (TBDMS-CDs) in Langmuir Monolayers: The Importance of a Spreading Solvent in the Preparation of LB Layers Suitable for Sensor Application

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• 作者：Micha Flasiski ; Marcin Broniatowski ; Nuria Vila Romeu ; Patrycja Dynarowicz-tka ; Amparo Gallardo Moreno ; Antonio Mendez Vilas ; M. Luisa Gonz&aacute ; lez Martí ; n
• 刊名：Journal of Physical Chemistry B
• 出版年：2008
• 出版时间：April 17, 2008
• 年：2008
• 卷：112
• 期：15
• 页码：4620 - 4628
• 全文大小：964K
• 年卷期：v.112,no.15(April 17, 2008)
• ISSN：1520-5207

文摘

Commercially available amphiphilic cyclodextrins, namely per-6-O-(tert-butyldimethylsilyl) mages/gifchars/alpha.gif" BORDER=0>, mages/gifchars/beta2.gif" BORDER=0 ALIGN="middle"> and mages/gifchars/gamma.gif" BORDER=0 >cyclodextrins (TBDMS-mages/gifchars/alpha.gif" BORDER=0>-, -mages/gifchars/beta2.gif" BORDER=0 ALIGN="middle">-, and -mages/gifchars/gamma.gif" BORDER=0 >-CDs) were subjected to a thorough Langmuir monolayercharacterization, using both traditional methods of surface manometry (mages/gifchars/pi.gif" BORDER=0 >/A isotherms, stability experiments)and modern micrometer/nanometer resolution (BAM, AFM) surface techniques. It has been found thatinconsistent behavior regarding the isotherms reproducibility obtained upon compression of TBDMS-mages/gifchars/beta2.gif" BORDER=0 ALIGN="middle">-CDs is due to the aggregation of the investigated molecules in chloroform and hexane, while goodreproducibility ensured a mixed spreading solvent system of hexane/isopropanol 7:3 (v/v). Although the stabilityof films dropped from chloroform and hexane/isopropanol solvents below the equilibrium surface pressure(ESP) was comparable, pronounced differences were observed at pressures above ESP. The investigatedTBDMS-CDs were successfully transferred onto cadmium stearate covered mica substrates. AFM imagesconfirmed the presence of discontinuous multilayered films (10 nm heights) spread from chloroform versusmonomolecular dispersion achieved in hexane/isopropanol.