Wong Lucas N, Jones Seamus D, Wood Kathleen, de Campo Liliana, Darwish Tamim, Moir Michael, Li Hua, Segalman Rachel A, Warr Gregory G, Atkin Rob
School of Molecular Sciences, The University of Western Australia, Crawley, Perth 6009, Australia.
Chemical Engineering Department and Materials Department, University of California, Santa Barbara, California 93106, USA.
Phys Chem Chem Phys. 2022 Feb 16;24(7):4526-4532. doi: 10.1039/d1cp05354j.
The conformation of the polycation in the prototypical polymeric ionic liquid (PIL) poly(3-methyl-1-aminopropylimidazolylacrylamide) bis(trifluoromethylsulfonyl)imide (poly(3MAPIm)TFSI) was probed using small-angle neutron scattering (SANS) and ultra-small-angle neutron scattering (USANS) at 25 °C and 80 °C. Poly(3MAPIm)TFSI contains microvoids which lead to intense low scattering that can be mitigated using mixtures of hydrogen- and deuterium-rich materials, allowing determination of the polycation conformation and radius of gyration (). In the pure PIL, the polycation adopts a random coil conformation with = 52 ± 0.5 Å. In contrast to conventional polymer melts, the pure PIL is not a theta solvent for the polycation. The TFSI anions, which comprise 48% v/v of the PIL, are strongly attracted to the polycation and act like small solvent molecules which leads to chain swelling analogous to an entangled, semi-dilute, or concentrated polymer solution in a good solvent.
在25℃和80℃下，使用小角中子散射（SANS）和超小角中子散射（USANS）对典型的聚合离子液体（PIL）聚（3-甲基-1-氨基丙基咪唑基丙烯酰胺）双（三氟甲基磺酰基）亚胺（聚（3MAPIm）TFSI）中的聚阳离子构象进行了探测。聚（3MAPIm）TFSI含有微孔，这会导致强烈的低散射，使用富含氢和氘的材料混合物可以减轻这种散射，从而确定聚阳离子的构象和回转半径（）。在纯PIL中，聚阳离子采用无规线团构象，= 52 ± 0.5 Å。与传统聚合物熔体不同，纯PIL对于聚阳离子而言不是θ溶剂。占PIL体积分数48%的TFSI阴离子被强烈吸引到聚阳离子上，并起到小溶剂分子的作用，导致链膨胀，类似于在良溶剂中的缠结、半稀或浓聚合物溶液。
