Super-resolution study of polymer mobility fluctuations near c*.
Super-resolution study of polymer mobility fluctuations near c*.
复制标题
c* 附近聚合物迁移率波动的超分辨率研究。
DOI：
10.1021/nn502856t
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发表时间：
2014
期刊：
影响因子：
17.1
通讯作者：
S. Granick
中科院分区：
文献类型：
--
作者：
J. T. King;Changqiang Yu;W. Wilson;S. Granick
合成聚合物溶液中的纳米尺度动态不均匀性是使用超分辨率光学显微镜检测。为此，我们映射的空间分辨率低于衍射极限的聚苯乙烯-甲苯溶液中的浓度波动，专注于聚合物重叠浓度附近的临界波动，c*。双光子超分辨显微镜适用于有机溶剂，并使用自制的STED-FCS系统与受激发射耗尽（STED）进行荧光相关光谱（FCS）。将用作示踪剂探针的聚苯乙烯（670 kg mol（-1），回转半径RG = 35 nm，用bodipy衍生物发色团末端标记）在室温下溶解在甲苯中（良溶剂），并与基质聚苯乙烯（3，840 kg mol（-1），RG = 97 nm，Mw/Mn = 1.04）混合，基质聚苯乙烯的浓度从稀到大于10 c * 变化。而对于稀溶液的强度强度相关函数遵循一个单一的扩散过程，它分裂开始在c* 意味着一个额外的松弛过程，提供的实验聚焦面积不大大超过聚合物滴的大小。我们确定较慢的模式为自扩散和越来越快的模式为相关的段波动，反映了合作扩散系数，Dcoop。这些真实空间的测量发现从动态测量推断的相关长度和那些从确定的限制，低于该限制扩散系数是独立的斑点大小之间的定量协议。这项研究被认为是说明潜在的进口到聚合物科学的超分辨率成像技术。
Nanoscale dynamic heterogeneities in synthetic polymer solutions are detected using super-resolution optical microscopy. To this end, we map concentration fluctuations in polystyrene-toluene solutions with spatial resolution below the diffraction limit, focusing on critical fluctuations near the polymer overlap concentration, c*. Two-photon super-resolution microscopy was adapted to be applicable in an organic solvent, and a home-built STED-FCS system with stimulated emission depletion (STED) was used to perform fluorescence correlation spectroscopy (FCS). The polystyrene serving as the tracer probe (670 kg mol(-1), radius of gyration RG ≈ 35 nm, end-labeled with a bodipy derivative chromophore) was dissolved in toluene at room temperature (good solvent) and mixed with matrix polystyrene (3,840 kg mol(-1), RG ≈ 97 nm, Mw/Mn = 1.04) whose concentration was varied from dilute to more than 10c*. Whereas for dilute solutions the intensity-intensity correlation function follows a single diffusion process, it splits starting at c* to imply an additional relaxation process provided that the experimental focal area does not greatly exceed the polymer blob size. We identify the slower mode as self-diffusion and the increasingly rapid mode as correlated segment fluctuations that reflect the cooperative diffusion coefficient, Dcoop. These real-space measurements find quantitative agreement between correlation lengths inferred from dynamic measurements and those from determining the limit below which diffusion coefficients are independent of spot size. This study is considered to illustrate the potential of importing into polymer science the techniques of super-resolution imaging.
影响因子：
10.8
作者：
C. Ullal;R. Schmidt;S. Hell;A. Egner
通讯作者：
C. Ullal;R. Schmidt;S. Hell;A. Egner
影响因子：
64.8
作者：
Eggeling, Christian;Ringemann, Christian;Hell, Stefan W.
通讯作者：
Hell, Stefan W.
影响因子：
8.6
作者：
Enderlein, Joerg
通讯作者：
Enderlein, Joerg