Nanofibers of 1,3-diphenyl-2-pyrazoline induced by cetyltrimethylammonium bromide micelles
Nanofibers of 1,3-diphenyl-2-pyrazoline induced by cetyltrimethylammonium bromide micelles
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DOI：
10.1002/anie.200350961
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发表时间：
2003-01-01
影响因子：
16.6
通讯作者：
Yang, GQ
中科院分区：
文献类型：
--
作者：
Fu, HB;Xiao, DB;Yang, GQ
近年来，低分子量（MW）活性化合物的有机纳米颗粒[1-7]越来越受到无机胶体晶体广泛研究的关注。[8-10]由于分子间范德华相互作用的存在，ONPs的电子和光学性质与无机纳米颗粒有着根本的不同此外，无机晶体中构造单元的取向是相同的，因为原子可以看作是硬球体；相比之下，有机分子的堆叠方式对ONPs的性能起着重要的作用。[4b， 6]就应用而言，ONPs的光学和电光性质的改变只能在中纳米或更低的纳米范围（50-500纳米）内实现，这使得材料合成和纳米颗粒制备具有更大的可变性和灵活性。[1-7]然而，对onp的调查仅处于初始阶段。到目前为止，合成控制onp形状的挑战取得了有限的成功在此，我们报道了在十六烷基三甲基溴化铵（CTAB）分子存在的水相中，自诱导模板生长产生1,3 -二苯基-2-吡唑啉（DP）纳米纤维。首先，DP分子溶入球形CTAB胶束的碳氢核心，诱导了CTAB胶束从球到棒的转变；然后诱导棒状CTAB胶束引导柱状DP纳米纤维模板的生长。结果表明，晶体充填力驱动DP分子在纳米纤维中以j型聚集体自组装。j型聚集体形成时伴随的性能变化以及通过纤维状形状的载流子迁移的自然路径可以被探索，以提高许多领域的器件性能。将DP/乙醇原液（100 μL, 5.0 mm）注入CTAB （5 mL）胶束水溶液中，搅拌5分钟，制备稳定的DP纳米颗粒。由于粒子的光散射，DP纳米颗粒在水中的分散表现出灰白色的浊度。有趣的是，DP颗粒的形态强烈依赖于CTAB （CCTAB）的浓度。水相中没有CTAB分子或CCTAB小于第一个临界胶束浓度（CMC, 0.9 mm）， DP分子会快速沉积。为了阐明CTAB分子的作用，我们选取了5个样品，分别标记为1-5，CCTAB= 5.4、4.0、2.7、1.8和0.9 mm。
In recent years, organic nanoparticles (ONPs) of low-molecular-weight (MW) active compounds [1–7] have increasingly become of interest in view of the extensive studies with inorganic colloidal crystals.[8–10] The electronic and optical properties of ONPs are fundamentally different from those of inorganic nanoparticles, because of the presence of van der-Waals intermolecular interactions.[11] Furthermore, the orientation of building units in inorganic crystals is identical since atoms can be regarded as hard spheres; in contrast, the stacking mode of organic molecules plays an important role in the properties of ONPs.[4b, 6] As far as the application is concerned, the modification of optical and electro-optical properties in ONPs, which are achievable only with particle sizes in the middle or lower nanometer range (50–500 nm), allows much more variability and flexibility in both material synthesis and nanoparticle preparation.[1–7] Investigations of ONPs, however, are only at their initial stages. Until now, the challenge of synthetically controlling the shape of ONPs has been met with limited success.[5] Herein, we report a self-inducing template growth to produce nanofibers of 1, 3-diphenyl-2-pyrazoline (DP) in the presence of cetyltrimethylammonium bromide (CTAB) molecules in an aqueous phase. Firstly, the solubilization of DP molecules into the hydrocarbon core of spherical CTAB micelles induces the sphere-to-rod transition of CTAB micelles; then the induced rodlike CTAB micelles direct the growth of cylindrical DP nanofibers like templates. It is found that the crystal packing forces drive DP molecules self-assembling as J-type aggregates in nanofibers. The concomitant property changes upon the formation of J-type aggregates as well as the natural path to carrier mobility through the fiberlike shape may be explored to enhance device performance in many fields.Stable DP nanoparticles were prepared by injecting a stock DP/ethanol solution (100 μL, 5.0 mm) to an aqueous micellar solution of CTAB (5 mL) and stirred for 5 minutes. The dispersions of DP nanoparticles into water exhibited an off-white turbidity because of the light scattering of the particles. Interestingly, the morphology of DP particles strongly depends on the concentration of CTAB (CCTAB). Without CTAB molecules in the aqueous phase or CCTAB is less than the first critical micelle concentration (CMC, 0.9 mm), DP molecules would deposit quickly. To elucidate the role played by CTAB molecules, five samples, labeled as 1–5, with CCTAB= 5.4, 4.0, 2.7, 1.8 and 0.9 mm, respectively, were used in our experiments.