Interplay between Crystallization and Phase Separation in PS‑<i>b</i>‑PMMA/PEO Blends: The Effect of Confinement

Interplay between phase separation and crystallization under confinement for the blends of PEO homopolymers with different molecular weight and PS-<i>b</i>-PMMA block copolymer is studied. Phase structures of the blends are investigated by atomic force microscope (AFM) and theoretically simulated by the dissipative particle dynamics (DPD) method, and a phase diagram describing the phase structure is established. Low molecular weight PEO (PEO2) disperses uniformly in the PMMA block domain and causes a transition from cylinder phase to perforated lamellar phase, while high molecular weight PEO (PEO20) causes expansion of the cylinder domains and formation of disordered domains. Crystallization and melting behavior of the blends are detected by differential scanning calorimetry (DSC). The results show the liquid–liquid phase separation between PEO homopolymer and PMMA block under PS-<i>b</i>-PMMA microphase-separated structure is suppressed due to the hard confinement caused by glassy PS block. As a result, in the blends of PS-<i>b</i>-PMMA/PEO2, PEO2 is unable to crystallize, and in the blends of PS-<i>b</i>-PMMA/PEO20, PEO20 shows a more obvious melting point depression compared with the homopolymer blends of PMMA/PEO20

Interplay between Crystallization and Phase Separation in PS‑<i>b</i>‑PMMA/PEO Blends: The Effect of Confinement

Interplay between phase separation and crystallization under confinement for the blends of PEO homopolymers with different molecular weight and PS-<i>b</i>-PMMA block copolymer is studied. Phase structures of the blends are investigated by atomic force microscope (AFM) and theoretically simulated by the dissipative particle dynamics (DPD) method, and a phase diagram describing the phase structure is established. Low molecular weight PEO (PEO2) disperses uniformly in the PMMA block domain and causes a transition from cylinder phase to perforated lamellar phase, while high molecular weight PEO (PEO20) causes expansion of the cylinder domains and formation of disordered domains. Crystallization and melting behavior of the blends are detected by differential scanning calorimetry (DSC). The results show the liquid–liquid phase separation between PEO homopolymer and PMMA block under PS-<i>b</i>-PMMA microphase-separated structure is suppressed due to the hard confinement caused by glassy PS block. As a result, in the blends of PS-<i>b</i>-PMMA/PEO2, PEO2 is unable to crystallize, and in the blends of PS-<i>b</i>-PMMA/PEO20, PEO20 shows a more obvious melting point depression compared with the homopolymer blends of PMMA/PEO20

Interplay between Crystallization and Phase Separation in PS‑<i>b</i>‑PMMA/PEO Blends: The Effect of Confinement

Interplay between phase separation and crystallization under confinement for the blends of PEO homopolymers with different molecular weight and PS-<i>b</i>-PMMA block copolymer is studied. Phase structures of the blends are investigated by atomic force microscope (AFM) and theoretically simulated by the dissipative particle dynamics (DPD) method, and a phase diagram describing the phase structure is established. Low molecular weight PEO (PEO2) disperses uniformly in the PMMA block domain and causes a transition from cylinder phase to perforated lamellar phase, while high molecular weight PEO (PEO20) causes expansion of the cylinder domains and formation of disordered domains. Crystallization and melting behavior of the blends are detected by differential scanning calorimetry (DSC). The results show the liquid–liquid phase separation between PEO homopolymer and PMMA block under PS-<i>b</i>-PMMA microphase-separated structure is suppressed due to the hard confinement caused by glassy PS block. As a result, in the blends of PS-<i>b</i>-PMMA/PEO2, PEO2 is unable to crystallize, and in the blends of PS-<i>b</i>-PMMA/PEO20, PEO20 shows a more obvious melting point depression compared with the homopolymer blends of PMMA/PEO20

Interplay between Crystallization and Phase Separation in PS‑<i>b</i>‑PMMA/PEO Blends: The Effect of Confinement

Interplay between phase separation and crystallization under confinement for the blends of PEO homopolymers with different molecular weight and PS-<i>b</i>-PMMA block copolymer is studied. Phase structures of the blends are investigated by atomic force microscope (AFM) and theoretically simulated by the dissipative particle dynamics (DPD) method, and a phase diagram describing the phase structure is established. Low molecular weight PEO (PEO2) disperses uniformly in the PMMA block domain and causes a transition from cylinder phase to perforated lamellar phase, while high molecular weight PEO (PEO20) causes expansion of the cylinder domains and formation of disordered domains. Crystallization and melting behavior of the blends are detected by differential scanning calorimetry (DSC). The results show the liquid–liquid phase separation between PEO homopolymer and PMMA block under PS-<i>b</i>-PMMA microphase-separated structure is suppressed due to the hard confinement caused by glassy PS block. As a result, in the blends of PS-<i>b</i>-PMMA/PEO2, PEO2 is unable to crystallize, and in the blends of PS-<i>b</i>-PMMA/PEO20, PEO20 shows a more obvious melting point depression compared with the homopolymer blends of PMMA/PEO20

Constructing Novel Si@SnO₂ Core–Shell Heterostructures by Facile Self-Assembly of SnO₂ Nanowires on Silicon Hollow Nanospheres for Large, Reversible Lithium Storage

Developing an industrially viable silicon anode, featured by the highest theoretical capacity (4200 mA h g^–1) among common electrode materials, is still a huge challenge because of its large volume expansion during repeated lithiation–delithiation as well as low intrinsic conductivity. Here, we expect to address these inherent deficiencies simultaneously with an interesting hybridization design. A facile self-assembly approach is proposed to decorate silicon hollow nanospheres with SnO₂ nanowires. The two building blocks, hand in hand, play a wonderful duet by bridging their appealing functionalities in a complementary way: (1) The silicon hollow nanospheres, in addition to the major role as a superior capacity contributor, also act as a host material (core) to partially accommodate the volume expansion, thus alleviating the capacity fading by providing abundant hollow interiors, void spaces, and surface areas. (2) The SnO₂ nanowires serve as a conductive coating (shell) to enable efficient electron transport due to a relatively high conductivity, thereby improving the cyclability of silicon. Compared to other conductive dopants, the SnO₂ nanowires with a high theoretical capacity (790 mA h g^–1) can contribute outstanding electrochemical reaction kinetics, further adding value to the ultimate electrochemical performances. The resulting novel Si@SnO₂ core–shell heterostructures exhibit remarkable synergy in large, reversible lithium storage, delivering a reversible capacity as high as 1869 mA h g^–1@500 mA g^–1 after 100 charging–discharging cycles