Local Glass Transition Temperature T g ( z ) Within Polystyrene Is Strongly Impacted by the Modulus of the Neighboring PDMS Domain
Local Glass Transition Temperature T g ( z ) Within Polystyrene Is Strongly Impacted by the Modulus of the Neighboring PDMS Domain
复制标题
聚苯乙烯内的局部玻璃化转变温度 Tg (z) 受到邻近 PDMS 域模量的强烈影响
DOI：
10.1021/acsmacrolett.0c00659
复制
发表时间：
2020
影响因子：
7.015
通讯作者：
Roth, Connie B.
中科院分区：
文献类型：
--
作者：
Gagnon, Yannic J.;Roth, Connie B.
用局域荧光法测定了聚二甲基硅氧烷（PDMS）微区附近聚苯乙烯（PS）的局部玻璃化转变温度Tg（z）曲线。通过改变碱与交联剂的比例，我们改变了交联密度，从而改变了PDMS的杨氏模量（Sylgard 184）。当PDMS模量在0.9 ~ 2.6MPa范围内变化时，离PS/PDMS界面z = 50 nm处的PS局部Tg（z）发生了40 K的位移，表明这种现象对邻近区域的刚性有很强的敏感性。与以前研究的弱不混溶体系相比，这种强不混溶体系的Tg（z）扰动在远离PS/PDMS界面处持续的程度（z = 65-90 nm）短得多，这归因于PS/PDMS的χ参数大一个数量级，界面宽度较小。
Profiles in the local glass transition temperatureTg(z) within polystyrene (PS) next to polydimethylsiloxane (PDMS) domains were determined using a localized fluorescence method. By changing the base to cross-linker ratio, we varied the cross-link density and, hence, the Young’s modulus of PDMS (Sylgard 184). The localTg(z) in PS at a distance ofz= 50 nm away from the PS/PDMS interface was found to shift by 40 K as the PDMS modulus was varied from 0.9 to 2.6 MPa, demonstrating a strong sensitivity of this phenomenon to the rigidity of the neighboring domain. The extent theTg(z) perturbation persists away from the PS/PDMS interface,z≈ 65–90 nm before bulkTgis recovered, is much shorter for this strongly immiscible system compared with the weakly immiscible systems studied previously, which we attribute to a smaller interfacial width, as the χ parameter for PS/PDMS is an order of magnitude larger.