Department of Chemistry and Faculty of Pharmacy, University of Montreal, CP 6128 Succursale Centre Ville, Montreal, QC, Canada H3C 3J7.
J Colloid Interface Sci. 2009 Dec 15;340(2):142-52. doi: 10.1016/j.jcis.2009.06.060. Epub 2009 Jul 1.
We describe herein the properties at the air/water (A/W) interface of hydrophobically end-modified (HM) poly(2-isopropyl-2-oxazoline)s (PiPrOx) bearing an n-octadecyl chain on both termini (telechelic HM-PiPrOx) or on one chain end (semitelechelic HM-PiPrOx) for different subphase temperatures and spreading solvents using the Langmuir film balance technique. The polymer interfacial properties revealed by the pi-A isotherms depend markedly on the architecture and molecular weight of the polymer. On cold water subphases (14 degrees C), diffusion of PiPrOx chains onto water takes place for all polymers in the intermediate compressibility region (5mNm(-1)). At higher subphase temperatures (36 and 48 degrees C), the HM-PiPrOx film exhibited remarkable stability with time. Brewster angle microscopy (BAM) imaging of the A/W interface showed that the polymer assembly was not uniform and that large domains formed, either isolated grains or pearl necklaces, depending on the polymer structure, the concentration of the spreading solution and the subphase temperature. The Langmuir films were transferred onto hydrophilic substrates (silica) by the Langmuir-Blodgett (LB) technique and onto hydrophobic substrates (gold) by Langmuir-Schaefer (LS) film deposition, resulting in the formation of adsorbed particles ranging in size from 200 to 500nm, depending on the polymer architecture and the substrate temperature. The particles presented "Janus"-like hydrophilic/hydrophobic characteristics.
我们在此描述了具有两端十八烷基链（端接 HM-PiPrOx）或一端十八烷基链（半端接 HM-PiPrOx）的疏水端修饰（HM）聚 2-异丙基-2-恶唑啉（PiPrOx）在不同亚相温度和铺展溶剂下在气/水（A/W）界面的性质，使用 Langmuir 膜天平技术。pi-A 等温线揭示的聚合物界面性质明显取决于聚合物的结构和分子量。在冷的水亚相（14°C）下，所有聚合物在中间压缩性区域（5mNm（-1））中都会发生 PiPrOx 链扩散到水中。在较高的亚相温度（36 和 48°C）下，HM-PiPrOx 膜表现出显著的时间稳定性。A/W 界面的掠入射反射显微镜（BAM）成像表明，聚合物组装不均匀，形成大的域，取决于聚合物结构、铺展溶液的浓度和亚相温度，这些域可以是孤立的颗粒或珍珠项链。Langmuir 膜通过 Langmuir-Blodgett（LB）技术转移到亲水基底（硅）上，通过 Langmuir-Schaefer（LS）膜沉积转移到疏水基底（金）上，形成大小在 200 到 500nm 之间的吸附颗粒，这取决于聚合物结构和基底温度。这些颗粒呈现出“Janus”型亲水/疏水特性。
