Conformation statistics of macromolecules in dilute solution is one of the fundamental issues in polymer physics. Herein, we experimentally explore the average conformation of model randomly hyperbranched chains composed of uniform subchains near the θ point (T_θ,_hyper). We have, for the first time, experimentally verified the size-mass scaling relation for model hyperbranched chains near T_θ,_hyper. Quantitatively, the Flory exponent (ν) in the size-mass scaling <R> ∼ N_t^νN_b^μ is determined to be ν ≈ 0.46 in good solvent toluene and to be 0.40 ≤ ν ≤ 0.47 in theta solvent cyclopentane. Our result agrees well with the theoretical prediction by Daoud and Joanny (ν = 7/16) near the θ point. Further, using molecular dynamics simulation, we demonstrate that probing the specific temperature region, at which model hyperbranched polymers exhibit a ν ≈ 0.5 size-mass scaling, would be a more appropriate way to find the real theta temperature for the highly branched systems in the simulation study. Overall, the present study clearly reveals that the size-mass scaling exponent of hyperbranched chains with uniform subchains is very close to 0.5 near the theta condition, which unambiguously illustrates the non-negligible role of three-body interaction in dominating the conformation of hyperbranched chains under the θ solvent condition.

中文翻译：

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θ点附近的稀溶液中具有均匀分支支链的超支化聚合物的链构型

稀溶液中大分子的构象统计是高分子物理学中的基本问题之一。在此，我们探索实验模型中的θ点附近均匀子链（构成随机超支化链的平均构象Ť _θ，_超）。我们，第一次，实验验证了模型的大小，质量缩放关系超支近链牛逼_θ，_超。定量地，在尺寸质量缩放<弗洛里指数（ν）- [R >〜Ñ_吨^ν Ñ _b ^μ在良好的溶剂甲苯中测定为ν≈0.46，在θ溶剂环戊烷中测定为0.40≤v≤0.47。我们的结果与Daoud和Joanny（ν= 7/16）在θ点附近的理论预测非常吻合。此外，使用分子动力学模拟，我们证明探测模型超支化聚合物表现出ν≈0.5尺寸-质量标度的特定温度区域，将是一种更合适的方法，可以找到高支化体系中真实theta温度。模拟研究。总体而言，本研究清楚地表明，在theta条件下，具有均匀亚链的超支链的大小质量缩放指数非常接近0.5，