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Core–shell structured poly(vinylidene fluoride)- <i>grafted</i> -BaTiO <sub/>3</sub> nanocomposites prepared <i>via</i> reversible addition–fragmentation chain transfer (RAFT) polymerization of VDF for high energy storage capacitors
摘要： Core–shell structured poly(vinylidene fluoride)-grafted-barium titanate (PVDF-g-BaTiO3) nanocomposites were prepared by surface-initiated reversible addition–fragmentation chain transfer (RAFT) polymerization of VDF from the surface of functionalized BaTiO3 nanoparticles. The ceramic fillers were first surface-modified with xanthate functions to further allow the RAFT grafting of VDF. A series of structured core shells were synthesized by tuning the feed [initiator functionalized nanoparticles]0 : [monomer]0 ratio, varying from 3 to 5, 10 and 20 wt%. Fourier transform infrared spectroscopy (FTIR), high resolution magic angle spinning (HRMAS) NMR and thermogravimetric analysis (TGA) confirmed the successful surface functionalization of the ceramic filler and the grafting of the PVDF shell onto the surface of the BaTiO3 cores. Transmission electron microscopy results revealed that BaTiO3 nanoparticles are covered by thin shells of PVDF, with thickness varying from 2.2 to 5.1 nm, forming a core–shell structure. HRMAS 19F indicated a grafting of 39–50 units of VDF. X-ray diffraction measurements together with FTIR measurements revealed that PVDF was present in the α form. Thermal properties also indicated that the addition of a small amount of the BaTiO3 filler to the PVDF matrix increased the melting temperature from 168 °C for neat PVDF to 173 °C for PVDF-g-BaTiO3 (20 wt%) and decreased the crystallinity of PVDF from 47% to 21%.
关键词： Nanocomposites,Core-Shell Structure,BaTiO3,PVDF,RAFT Polymerization,Polymer Chemistry,Dielectric Materials
更新于2025-09-19 17:15:36
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Donor–acceptor type black phosphorus nanosheets covalently functionalized with a conjugated polymer for laser protection
摘要： Covalent functionalization of two-dimensional black phosphorus (BP) with conjugated polymers would be favorable to improve its environmental stability and solubility in organic solvents, and thereby to open a way to explore more applications of BP in the fields of optoelectronics, electronics and photonics. As a proof-of-concept application, soluble donor–acceptor type BP nanosheets covalently functionalized with poly[(1,4-diethynyl-2,5-bis(hexyloxy)benzene)-alt-benzo[c]thiadiazole] (hereafter called PDBT-BP) were synthesized through Sonogashira–Hagihara coupling polymerization, and embedded into an optically nonactive transparent poly(methylmethacrylate) (PMMA) matrix to produce the PMMA-based PDBT-BP film for nonlinear optics. In contrast to BP/PMMA, PDBT-BP/PMMA and PDBT/BP blends/PMMA films, the annealed PDBT-BP/PMMA film, which was heated at 150 °C under dry argon for 1 h, shows more excellent reverse saturable absorption (RSA) behavior, with a larger nonlinear absorption coefficient (βeff ) of 208.16 cm GW?1 and an imaginary third-order susceptibility (Im χ(3)) of 8.89 × 10?11 esu at a pulse energy of 400 μJ. The achieved optical limiting (OL) threshold is 4.44 J cm?2 (0.74 GW cm?2), smaller than that of the non-annealed PDBT-BP/PMMA film (5.64 J cm?2). The SA (saturable absorption) to RSA transition observed at a low incident laser intensity could be used to realize all-optical intensity-dependent logic gates in the near future.
关键词： Conjugated Polymer,Laser Protection,Polymer Chemistry,Black Phosphorus,Nonlinear Optics
更新于2025-09-16 10:30:52
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Precisely Controlled Microsphere Design via Visible‐Light Cross‐Linking of Functional Prepolymers
摘要： A new strategy for particle synthesis is enabled by utilizing modern synthetic, polymer, and photochemical techniques to facilitate the synthesis of highly narrow–disperse multifunctional microspheres from visible-light induced crosslinking of prepolymers in both a single and dual polymer system. The approach requires no stabilizers, bases, or initiators, and proceeds at ambient temperature to yield microspheres with a tunable size range (0.25–5 μm) in less than 4 h, depending largely on solvent composition, but also polymer concentration (2–10 mg mL?1), ratio, and irradiation intensity (3–20 W). Critically, the visible-light induced dimerization reaction exploited herein enables simple functional particle syntheses via a single polymer system. Underpinned by an in-depth kinetic analysis of the particle formation as well as a detailed small molecule study, the mechanism for particle formation is also elucidated. Importantly, inherent advantages of the system are exploited for surface functionalization of residual acrylate and hydroxyl groups (generating inherently fluorescent particles).
关键词： polymer chemistry,photochemistry,materials chemistry,precipitation polymerization,particle synthesis
更新于2025-09-11 14:15:04
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Functional Macromolecule‐Enabled Colloidal Synthesis: From Nanoparticle Engineering to Multifunctionality
摘要： The synthesis of well-defined inorganic colloidal nanostructures using functional macromolecules is an enabling technology that offers the possibility of fine-tuning the physicochemical properties of nanomaterials and has contributed to a broad range of practical applications. The utilization of functional reactive polymers and their colloidal assemblies leads to a high level of control over structural parameters of inorganic nanoparticles that are not easily accessible by conventional methods based on small-molecule ligands. Recent advances in polymerization techniques for synthetic polymers and newly exploited functions of natural biomacromolecules have opened up new avenues to monodisperse and multifunctional nanostructures consisting of integrated components with distinct chemistries but complementary properties. Here, the evolution of colloidal synthesis of inorganic nanoparticles is revisited. Then, the new developments of colloidal synthesis enabled by functional macromolecules and practical applications associated with the resulting optical, catalytic, and structural properties of colloidal nanostructures are summarized. Finally, a perspective on new and promising pathways to novel colloidal nanostructures built upon the continuous development of polymer chemistry, colloidal science, and nanochemistry is provided.
关键词： polymer chemistry,nanochemistry,multifunctionality,colloidal synthesis,functional macromolecules,nanoparticle engineering,colloidal science
更新于2025-09-11 14:15:04