| 1. |
- Cao, W., et al.
(författare)
-
In Situ Study of FePt Nanoparticles-Induced Morphology Development during Printing of Magnetic Hybrid Diblock Copolymer Films
- 2022
-
Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 32:4, s. 2107667-
-
Tidskriftsartikel (refereegranskat)abstract
- The development of magnetic hybrid films containing diblock copolymers (DBCs) and magnetic nanoparticles (NPs) by printing is a highly promising method for scalable and low-cost fabrication. During printing, the drying and arrangement kinetics of the DBC and magnetic NPs play an important role in the film formation concerning morphology and magnetic properties. In this study, the morphology evolution of ultrahigh molecular weight DBC polystyrene-block-poly(methyl methacrylate) and magnetic iron platinum (FePt) NPs is investigated with grazing-incidence small-angle X-ray scattering (GISAXS) in situ during printing. For comparison, a pure DBC film is printed without FePt NPs under the same conditions. The GISAXS data suggest that the addition of NPs accelerates the solvent evaporation, leading to a faster film formation of the hybrid film compared to the pure film. As the solvent is almost evaporated, a metastable state is observed in both films. Compared with the pure film, such a metastable state continues longer during the printing process of the hybrid film because of the presence of FePt NPs, which inhibits the reorganization of the DBC chains. Moreover, investigations of the field-dependent magnetization and temperature-dependent susceptibility indicate that the printed hybrid film is superparamagnetic, which makes this film class promising for magnetic sensors.
|
|
| 2. |
- Beladi-Mousavi, S. M., et al.
(författare)
-
Poly(vinylferrocene)-Reduced Graphene Oxide as a High Power/High Capacity Cathodic Battery Material
- 2016
-
Ingår i: Advanced Energy Materials. - : Wiley. - 1614-6840 .- 1614-6832. ; 6:12
-
Tidskriftsartikel (refereegranskat)abstract
- The preparation and performance of a new cathodic battery material consisting of a composite of poly(vinylferrocene) (PVFc) and reduced graphene oxide (rGO) is described. It shows the highest charge/discharge efficiency (at a rate of 100 A g(-1)) ever reported for ferrocene-polymer materials. The composite allows for specific capacities up to 0.21 mAh cm(-2) (770 mC cm(-2), 29 mu m film thickness) at a specific capacity density of 114 mAh g(-1) and less than 5% performance decay over 300 cycles. The composite material is binder free and the charge storing PVFc accounts for 88% of the total weight of the cathodic material. The superb performance is based on (i) perfect self-assembling of oxidized PVFc on graphene oxide (GO) leading to PVFc@GO, (ii) its stepwise (n steps) transfer onto a current collector (CC) (PVFc@GO)(n) @CC (n = drop casting steps), and (iii) the efficient electrochemical transformation of GO into rGO in the composite using viologen as homogeneous electrocatalyst. The self-assembling step is analyzed by zeta potential and atomic force microscopy (AFM) studies, demonstrating heavy ferrocene loading on GO and a mesoporous composite structure, respectively. Complete GO/rGO transition and quantitative ClO4- on breathing of the composite are found by electrochemical quartz crystal microbalance and by electrochemical AFM.
|
|
| 3. |
- Schottner, S., et al.
(författare)
-
Amine-Containing Block Copolymers for the Bottom-Up Preparation of Functional Porous Membranes
- 2019
-
Ingår i: Macromolecules. - : American Chemical Society (ACS). - 0024-9297 .- 1520-5835. ; 52:7, s. 2631-2641
-
Tidskriftsartikel (refereegranskat)abstract
- The remarkable ability of biological systems to specifically recognize, sort, and process molecules encourages the development of novel bio-inspired membranes and interfaces. Herein, we focus on the functionalization of amphiphilic polystyrene-block-poly(2-hydroxyethyl methacrylate) (PS-b-PHEMA) with the amino acid glycine yielding polar block segments with primary amine functionalities. Excellent control over the tailored block copolymer (BCP) synthesis and functionalization is proven by size exclusion chromatography (SEC), H-1 solution NMR, and N-15 solid state NMR spectroscopy. For the first time, BCPs containing primary amines were used for the self-assembly and non-solvent induced phase separation (SNIPS) process for the preparation of isoporous and integral asymmetric membranes. Hexagonally arranged open pores with diameters of 19 rim were obtained as shown by scanning electron microscopy (SEM), atomic force microscopy (AFM), and pH-dependent water flux measurements. Additionally, the primary amine was subjected to convenient postmodification protocols. For instance, (fluorescent) dye molecules could be easily incorporated into the membrane structure, and peptide synthesis on the inner pore wall of the membrane could be accomplished. These novel and tailored porous materials will pave the way to a new generation of BCP membranes containing bio-inspired moieties and functionalities at the interfaces.
|
|
