Authors: Miriam M. Unterlass | Shinji Ando | Ophelia K. C. Tsui
Source: Macromolecular Chemistry and Physics (article, 2018-02-01)
Field: Chemistry — Spectroscopy

Polymer Characterization and Morphology Polymers belong to a materials class of the utmost importance. In the form of proteins or polysaccharides, polymers constitute the very building blocks of life. Artificial polymers, on the other hand, are involved in various other aspects of our daily life, most prominently in the form of plastic. Our shelves at home, the materials that fill our toys and CDs, the paint that makes our floor shine—everything is made out of polymers. The ever increasing presence of polymers in our daily lives is based on a set of striking features, most importantly their low weight imparted by being composed of light elements (mostly C, H, N, S, and halogens); abundance of these elements (that drives the cost down); and the relatively easy ways to process them, as enabled by their macromolecular nature generating viscoelasticity and ductility. Nowadays, polymer synthesis and (nano-)structuring have become more and more refined and allow for increasingly fine-tuned properties that generate both the necessity for fundamental understanding of structure-property relations and advanced characterization techniques. Therefore, we have with this special issue set out to assemble and highlight recent developments in polymer characterization and morphology. This issue features excellent contributions showcasing novel and sophisticated polymer characterization techniques that allow for further understanding of long-standing problems in polymer physics as well as recent developments of novel polymer materials. The topics covered include conducting polymers and their characterization via electrically detected magnetic resonance (EDMR) spectroscopy (Naoki Asakawa) and solid-state nuclear magnetic resonance, NMR (Michael Ryan Hansen). There are also additional sophisticated NMR experiments that could help to understand the coupled dynamics between the crystalline and amorphous regions in polymers (solid-state NMR, Toshikazu Miyoshi); chemical structure of natural rubber end-groups (Takehiro Kitaura, cryo-NMR); and polymer co-network formation (Kay Saalwächter, low-field multiple-quantum NMR). One can also find recent advances in the fundamental understanding of confinement-induced perturbations to the glassy behaviors of polymers as probed by (ultrafast) thermal analyses (Wenbing Hu, Dongshan Zhou), and by fluorescence techniques (Connie Roth: Local Tg profile near the interface between two polymers; Keiji Tanaka: time-resolved fluorescence anisotropy measurement; Rodney Priestley: a review on fluorescence techniques). Additional characterization topics covered in this issue include atomic force microscopy (AFM), characterizations of irreversibly adsorbed polymer nanolayers (Tadanori Koga), single-chain globule-coil transition (Ken Nakajima), and polymer crystallization (James Forrest); variable-temperature p-polarized multiple-angle incidence resolution spectroscopy, VT pMAIRS, a study of chain orientations in thin-film aromatic polyimides (Ryohei Ishige); transmission electron microscopy (TEM) for polymer morphology visualization (Sophie Norvez); a study on factors that influence the creep resistance of almost molten polyethylene blends (Christian Müller); a review on microrheology (Wei Liu); and a structure-anisotropic thermal expansion study on aromatic polyimide films (Shinji Ando). Nucleation, crystallization, and crystallinity of polymers are studied in several contributions (Christoph Schick: polarized optical microscopy and fast scanning chip calorimetry; Günter Reiter: control of polymer crystallization kinetics; Paola Rizzo: IR and Raman vibrational spectroscopic study of polymer chains in the mesomorphic phase; and Miriam Unterlass: morphology control of crystalline polyimides). Other morphologies investigated range from fibrous gels (Yasuhiro Matsuda) and hollow microcapsules (Bongjun Yeom) to PVA films with improved water solubility (Jun Hua), water absorbing foams (Yuanpeng Li), and microphase-separated structures in liquid-crystalline polymers (Masatoshi Tokita). Finally, this special issue also covers several exciting contributions in the field of materials design, including polymers for fuel cells (Xiuhua Li), polymer crystallization at curved interfaces (Christopher Li), irreversibly adsorbed polymer layers (Simone Napolitano), and supramolecular assembly of nano-building blocks (Stephen Cheng). We are grateful for the opportunity to guest-edit this special issue, which in its present form reflects the breadth of current trends in polymer materials research around the globe. We would like to give special thanks to Mara Staffiliani and her team for providing us unwavering support and guidance throughout the process. Above all, we are indebted to all the authors of this special issue for their inspirational contributions, which we believe will make this special issue a useful reference for many years to come. Characterization (materials science) ; Polymer ; Polymer science ; Materials science ; Nanotechnology ; Composite material Advanced NMR Techniques and Applications ; NMR spectroscopy and applications ; Advanced MRI Techniques and Applications