Efficient and Tunable White‐Light Emission Using a Dispersible Porous PolymerJames, Alex M.; Dawson, Robert
doi: 10.1002/marc.202000176pmid: 32449562
A dispersible porous polymer (PEG113‐b‐DVB800‐co‐AA200) based on the controlled radical polymerization of divinylbenzene and acrylic acid with a poly(ethylene glycol) (PEG) macrochain transfer agent (macro‐CTA) is synthesized and postsynthetically modified with anthracene. This blue‐emitting porous polymer is used to encapsulate the yellow‐emitting fluorophore rhodamine B into its core, resulting in a white‐light emitting dispersion with a quantum yield of 38% and commission internationale de l’éclairage coordinates of (X = 0.33, Y = 0.32).
PEGylation of Fluorescein by Enzyme‐Catalyzed “Click” Michael AdditionShrikhande, Gayatri; Mulay, Prajakatta; Puskas, Judit E.
doi: 10.1002/marc.202000163pmid: 32431048
This paper reports the first “Click” Michael addition catalyzed by Candida antarctica lipase B (CALB) between fluorescein o‐acrylate and thiol‐functionalized poly(ethylene glycol)s (HS‐PEG‐SH, Mn = 1200 g mol−1, Đ = 1.14, and Mn = 2200 g mol−1, Đ = 1.09). The progress of the reactions is monitored with 1H‐NMR spectroscopy. In the absence of CALB, the reaction does not go to completion even after 18 h but completes in less than 2 min when CALB is added. Similarly, the reaction with HS‐PEG‐SH having Mn = 2200 g mol−1 and Đ = 1.09 completes in less than 2 min by CALB catalysis. The structures of the products are also confirmed by 13C‐NMR. This enzyme‐catalyzed “Click” Michael addition is found to be a powerful tool to synthesize fluorescein‐based polymeric conjugates for a wide variety of applications.
Electrophoretic Adhesion of Conductive HydrogelsAsoh, Taka‐Aki; Nakamura, Megumi; Shoji, Tatsuya; Tsuboi, Yasuyuki; Uyama, Hiroshi
doi: 10.1002/marc.202000169pmid: 32400894
For the development of next‐generation wearable and implantable devices that connect the human body and machines, the adhesion of a conductive hydrogel is required. In this study, a conductive hydrogel is adhered using an electrophoretic approach through polyion complex formation at the interface of the hydrogels. Cationic and anionic conductive hydrogels adhere to anionic and cationic hydrogels, respectively. Moreover, the cationic and anionic conductive hydrogels adhere strongly to each other and the adhered conductive hydrogels exhibit conductivity. De‐adhesion is possible by adding a salt and re‐adhesion is demonstrated under aqueous conditions. It is believed that this innovative adhesion strategy for conductive hydrogels will be a fundamental technology for the connecting “soft” people and “hard” machines.
Distinctive Optical Properties of Hierarchically Ordered Nanostructures Self‐Assembled from Multiblock Copolymer/Nanoparticle MixturesLiu, Zaojin; Xu, Zhanwen; Wang, Liquan; Lin, Jiaping
doi: 10.1002/marc.202000131pmid: 32329165
Hybrid materials with hierarchical nanostructures are of great interest for their advanced functions. However, the effect of the formation of hierarchical nanostructures on properties is not well understood. Here, through combining dissipative particle dynamics simulation and the finite‐difference time‐domain method, the optical properties of hierarchically ordered nanostructures formed by mixtures of A(BC)n multiblock copolymers and nanoparticles (NPs) are investigated. A series of hierarchically ordered nanostructures with multiple small‐length‐scale hybrid domains are obtained from the self‐assembly of A(BC)n/NP. An increase and blueshift in optical absorption are observed when the number of small‐length‐scale hybrid domains increases. The small‐length‐scale hybrid domains enhance light scattering, which consequently contributes to the improved optical performance. These findings can yield guidelines for designing hierarchically ordered functional nanocomposites with light‐harvesting characteristics.
Selective Bond Cleavage in Informational Poly(Alkoxyamine Phosphodiester)sCavallo, Gianni; Clément, Jean‐Louis; Gigmes, Didier; Charles, Laurence; Lutz, Jean‐François
doi: 10.1002/marc.202000215pmid: 32449253
The collision‐induced dissociation (CID) of sequence‐defined poly(alkoxyamine phosphodiester)s is studied by electrospray ionization mass spectrometry. These informational polymers are synthesized using three different nitroxide building blocks, namely proxyl‐, SG1‐, and TEMPO‐derivatives. For a polymer containing TEMPO‐ and SG1‐based main chain alkoxyamines, it is found that both types of alkoxyamines break in CID tandem mass spectrometry (MS/MS). However, SG1‐sites are preferentially cleaved and this predominance can be increased by reducing collision energy, even though selective bond fragmentation is not observed. On the other hand, for a polymer containing proxyl‐ and SG1‐alkoxyamines, selective bond cleavage is observed at all studied collision energies. The SG1‐alkoxyamines can be first cleaved in MS/MS conditions and secondly the proxyl‐alkoxyamines in pseudo‐MS3 conditions. These results open up interesting new avenues for the design of readable, erasable or programmable informational polymers.
Isocyanoacetate‐Aldehyde Polymerization: A Facile Tool toward Functional Oxazoline‐Containing PolymersCheng, Tianyu; Chen, Yizhao; Ding, Jie; Qin, Anjun; Tang, Ben Zhong
doi: 10.1002/marc.202000179pmid: 32463567
As an important nitrogen source, isocyanides have been involved in numerous organic reactions. As a result, many complicated compounds have been successfully synthesized through isocyanide chemistry. However, compared with its popular research in organic reactions, the application of isocyanides in polymerization is less investigated. In this work, a new polymerization based on isocyanide monomers is established. By simply mixing diisocyanoacetates and dialdehydes in the presence of a catalytic system of CuCl/PPh3/organobase in dichloromethane at room temperature readily produces soluble and thermally stable oxazoline‐containing polymers with moderate weight‐averaged molecular weights (Mw up to 11 200) in excellent yields (up to 97%) after 6 h. Furthermore, introducing the tetraphenylethene moiety into the main chains endows the resultant polymers with aggregation‐induced emission, which can function as fluorescent probes for Fe3+ ion detection with high sensitivity and selectivity. This work not only enriches the family of isocyanide‐based polymerizations but also provides an efficient tool for the preparation of functional heterocycle‐containing polymers.