AbstractThe properties of a dendronized linear polymer (DP) in dilute solutions depending on solvent quality and temperature are described. The polymer has a contour length of Lc = 1,060 nm. The sample of the fourth generation (PG4) was analyzed in the thermodynamically good solvents dioxane, chloroform, and methanol. The wormlike macromolecule has a persistence length lp = 7 nm in dioxane and a cross-section radius determined by small angle X-ray scattering (SAXS) of Rc (SAXS) = 2.8 nm. The bulk density of PG4 determined by SAXS was compared with solution density. Evidence for substantial swelling of the cross-section was found. Toluene acts as a thermodynamically poor solvent (θ solvent). Above the θ temperature Tθ, a strong temperature dependence of the size and the Young’s modulus E was observed. Following Odijk, E/kBT ∼1 was found. Below Tθ, a regime characterized by unswelling of the wormlike chains was observed. The results suggest that DPs can be described as soft colloid filaments, which are subject to commonly observed interactions in colloidal systems. A phase diagram indicates a regime below Tθ in which fluctuations of osmotic pressure inside the filaments result in periodic undulation of the chains. In summary, introducing a dense dendritic shell around the backbone converts conventional polymers into molecular colloids. Figureᅟ

中文翻译：

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树枝化线性聚合物中的溶剂诱导现象


摘要描述了稀溶液中树枝化线性聚合物（DP）的性质取决于溶剂质量和温度。该聚合物的轮廓长度为 Lc = 1,060 nm。第四代 (PG4) 样品在热力学良好溶剂二恶烷、氯仿和甲醇中进行分析。蠕虫状大分子在二恶烷中的持久长度lp = 7 nm，截面半径由小角X射线散射(SAXS)确定，Rc (SAXS) = 2.8 nm。将 SAXS 测定的 PG4 堆积密度与溶液密度进行比较。发现了横截面大幅膨胀的证据。甲苯充当热力学不良溶剂（θ溶剂）。在 θ 温度 Tθ 以上，观察到尺寸和杨氏模量 E 具有很强的温度依赖性。继 Odijk 之后，发现了 E/kBT ∼1。在 Tθ 以下，观察到以蠕虫状链不膨胀为特征的状态。结果表明，DP 可被描述为柔软的胶体丝，在胶体系统中会发生常见的相互作用。相图表明低于 Tθ 的状态，其中丝内渗透压的波动导致链的周期性波动。总之，在主链周围引入致密的树枝状壳可将传统聚合物转化为分子胶体。图ᅟ