Polymerization-induced structural transitions have gained attention recently due to the ease of creating and modifying nanostructured materials with controlled morphologies and length scales. Here, we show that order-order and disorder-order nanostructural transitions are possible using in situ polymer grafting from the diblock polymer, poly(styrene)--poly(butadiene). In our approach, we are able to control the resulting nanostructure (lamellar, hexagonally packed cylinders, and disordered spheres) by changing the initial block polymer/monomer ratio. The nanostructural transition occurs by a grafting from mechanism in which poly(styrene) chains are initiated from the poly(butadiene) block via the creation of an allylic radical, which increases the overall molecular weight and the poly(styrene) volume fraction. The work presented here highlights how the chemical process of converting standard linear diblock copolymers to grafted block polymers drives interesting and controllable polymerization-induced morphology transitions.
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http://dx.doi.org/10.1021/acsmacrolett.8b00378 | DOI Listing |
Nanomaterials (Basel)
December 2024
Key Laboratory for Nonferrous Materials (MOE), School of Materials Science and Engineering, Central South University, Changsha 410083, China.
Magnetic one-dimensional nanostructures show great potential in spintronics and can be used as basic building blocks for magnetic materials and devices with multiple functions. In this study, transition group atomic chains (V, Cr, Mn, Fe, Co, and Ni) are introduced into nonmagnetic MoS with a 4|8ud-type grain boundary. Based on first-principles calculations, the V atomic chains show good thermodynamic stability and can self-assemble along the grain boundary direction.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
School of Materials Science & Engineering, Nanyang Technological University, Singapore 639798, Singapore.
This study investigates the effects of homopolymer additives and kinetic traps on the self-assembly of poly(ethylene glycol)-b-poly(lactide) (PEG-PLA) block copolymer (BCP) nanostructures in aqueous environments. By using non-adsorbing PEG homopolymers to kinetically trap PEG-PLA nanostructures, we demonstrate that varying the concentration and molecular weight of the added PEG induces a reversible micelle-to-vesicle transition. This transition is primarily driven by changes in the molecular geometry of the PEG-PLA BCPs due to excluded volume screening effects.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
School of Nuclear Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China.
Transition metal nitrides have extensive applications, including magnetic storage devices, hardware resistance coatings, and low-temperature fuel cells. This study investigated the structural, electrical, and mechanical properties of thin zirconium nitride (ZrN) films by examining the effects of laser irradiation times. Thin ZrN films were deposited on glass substrates using pulsed DC magnetron sputtering and irradiated with a diode laser for 6 and 10 min.
View Article and Find Full Text PDFBiosensors (Basel)
November 2024
Department of BioNano Technology, Gachon University, 1342 Seongnamdae-ro, Sujeong-gu, Seongnam 13120, Republic of Korea.
Choline is an important molecule in monitoring food safety and infant nutrition. Here, we report Ce nanogels synthesized by atom transfer radical polymerization (ATRP) employing Ce-coordinated acryloyl-lysine polymer brushes (Ce@SiO NGs) as highly efficient cascade nanozymes for colorimetric detection of choline. The synthesized Ce@SiO NGs demonstrated remarkable peroxidase-like activity with a porous exterior, which are essential to entrap choline oxidase (COx) to yield COx@Ce@SiO NGs and construct a cascade reaction system to detect choline.
View Article and Find Full Text PDFAnal Chem
December 2024
Phenikaa University Nano Institute (PHENA), Phenikaa University, Hanoi 12116, Vietnam.
Surface-enhanced Raman spectroscopy (SERS) is a powerful analytical technique, yet it faces challenges with certain probe molecules exhibiting weak or inactive signals, limiting their applicability. In a recent study, we investigated this phenomenon using a set of four probe molecules─chloramphenicol (CAP), 4-nitrophenol (4-NP), amoxicillin (AMX), and furazolidone (FZD)─deposited on Ag-based nanostructured SERS substrates. Despite being measured under identical conditions, CAP and 4-NP exhibited SERS activity, while AMX and FZD did not.
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