Two dimensional size controlled confinement of poly(vinyl pyrrolidone) in the interlayer space of swelling clay mineral

2012 ◽  
Vol 3 (4) ◽  
pp. 1069 ◽  
Author(s):  
Minoru Sohmiya ◽  
Shingo Omata ◽  
Makoto Ogawa
Keyword(s):  
Clay Mineral ◽  
Interlayer Space ◽  
Vinyl Pyrrolidone ◽  
Two Dimensional ◽  
Swelling Clay ◽  
Poly Vinyl Pyrrolidone ◽  
Size Controlled

In Situ Synthesis of Size-Controlled Silver/Poly(Methyl Methacrylate) Nanocomposite

2017 ◽  
Vol 727 ◽  
pp. 514-518
Author(s):  
Chun Gu ◽  
Guo Qiang Luo ◽  
Rui Zhi Zhang ◽  
Jian Zhang ◽  
Yuan Li ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Trace Amount ◽  
Reaction System ◽  
Vinyl Pyrrolidone ◽  
Pmma Matrix ◽  
Transmission Electron ◽  
Poly Vinyl Pyrrolidone ◽  
Size Controlled ◽  
Controllable Size

In this work, monodispersed silver nanoparticles with controllable size have been successfully in situ synthesized in PMMA matrix. NaHS, HCl and poly (vinyl pyrrolidone) (PVP) were used to optimize the nucleation and growth of silver nanocrystalline. UV–vis analysis and transmission electron microscopy (TEM) were used to characterize the size and dispersion of silver nanoparticles in the Ag/PMMA nanocomposites. The results show that silver nanoparticles homogeneously distribute in PMMA/DMF sol and the particle size of silver nanoparticles increase with the increasing of time. The nucleation of Ag atoms can be facilitated through the addition of a trace amount of NaHS to generate Ag2S clusters as heterogeneous nuclei. Introducing a trace amount of Cl- into the reaction system can effectively reduce the growth rate of the nanoparticles and thus generating more uniform silver nanoparticles in PMMA matrix.

Relating the dynamics of hydrated poly(vinyl pyrrolidone) to the dynamics of highly asymmetric mixtures and polymer blends

2021 ◽  
pp. 115907
Author(s):  
Kaito Sasaki ◽  
Masanobu Takatsuka ◽  
Naoki Shinyashiki ◽  
Kia L. Ngai
Keyword(s):  
Polymer Blends ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Pyrrolidone

scholarly journals ALD coating of centrifugally spun polymeric fibers and postannealing: case study for nanotubular TiO2 photocatalyst

2021 ◽  
Author(s):  
Martina Rihova ◽  
Oksana Yurkevich ◽  
Martin Motola ◽  
Ludek Hromadko ◽  
Zdeněk Spotz ◽  
...  
Keyword(s):  
Atomic Layer Deposition ◽  
Atomic Layer ◽  
Vinyl Pyrrolidone ◽  
Tio2 Photocatalyst ◽  
Polymeric Fibers ◽  
Layer Deposition ◽  
Centrifugal Spinning ◽  
Poly Vinyl Pyrrolidone

This work describes the synthesis of highly photocatalytically active TiO2 tubes (TiTBs) by combining centrifugal spinning and atomic layer deposition (ALD). Poly(vinyl pyrrolidone) (PVP) fibers were first produced by centrifugal...

scholarly journals Potential Implantable Nanofibrous Biomaterials Combined with Stem Cells for Subchondral Bone Regeneration

Materials ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3087
Author(s):  
Rana Smaida ◽  
Luc Pijnenburg ◽  
Silvia Irusta ◽  
Erico Himawan ◽  
Gracia Mendoza ◽  
...  
Keyword(s):  
Stem Cells ◽  
Bone Regeneration ◽  
Subchondral Bone ◽  
Therapeutic Potential ◽  
Sodium Hyaluronate ◽  
Vinyl Pyrrolidone ◽  
Regenerative Ability ◽  
Poly Vinyl Pyrrolidone

The treatment of osteochondral defects remains a challenge. Four scaffolds were produced using Food and Drug Administration (FDA)-approved polymers to investigate their therapeutic potential for the regeneration of the osteochondral unit. Polycaprolactone (PCL) and poly(vinyl-pyrrolidone) (PVP) scaffolds were made by electrohydrodynamic techniques. Hydroxyapatite (HAp) and/or sodium hyaluronate (HA) can be then loaded to PCL nanofibers and/or PVP particles. The purpose of adding hydroxyapatite and sodium hyaluronate into PCL/PVP scaffolds is to increase the regenerative ability for subchondral bone and joint cartilage, respectively. Human bone marrow-derived mesenchymal stem cells (hBM-MSCs) were seeded on these biomaterials. The biocompatibility of these biomaterials in vitro and in vivo, as well as their potential to support MSC differentiation under specific chondrogenic or osteogenic conditions, were evaluated. We show here that hBM-MSCs could proliferate and differentiate both in vitro and in vivo on these biomaterials. In addition, the PCL-HAp could effectively increase the mineralization and induce the differentiation of MSCs into osteoblasts in an osteogenic condition. These results indicate that PCL-HAp biomaterials combined with MSCs could be a beneficial candidate for subchondral bone regeneration.

scholarly journals Two-dimensional perovskites with alternating cations in the interlayer space for stable light-emitting diodes

Nanophotonics ◽  
2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yiyue Zhang ◽  
Masoumeh Keshavarz ◽  
Elke Debroye ◽  
Eduard Fron ◽  
Miriam Candelaria Rodríguez González ◽  
...  
Keyword(s):  
Thin Films ◽  
Near Infrared ◽  
Light Emitting Diodes ◽  
Interlayer Space ◽  
High Current Density ◽  
Operational Stability ◽  
Infrared Light ◽  
Two Dimensional ◽  
Commercial Development ◽  
Light Emitting

Abstract Lead halide perovskites have attracted tremendous attention in photovoltaics due to their impressive optoelectronic properties. However, the poor stability of perovskite-based devices remains a bottleneck for further commercial development. Two-dimensional perovskites have great potential in optoelectronic devices, as they are much more stable than their three-dimensional counterparts and rapidly catching up in performance. Herein, we demonstrate high-quality two-dimensional novel perovskite thin films with alternating cations in the interlayer space. This innovative perovskite provides highly stable semiconductor thin films for efficient near-infrared light-emitting diodes (LEDs). Highly efficient LEDs with tunable emission wavelengths from 680 to 770 nm along with excellent operational stability are demonstrated by varying the thickness of the interlayer spacer cation. Furthermore, the best-performing device exhibits an external quantum efficiency of 3.4% at a high current density (J) of 249 mA/cm2 and remains above 2.5% for a J up to 720 mA cm−2, leading to a high radiance of 77.5 W/Sr m2 when driven at 6 V. The same device also shows impressive operational stability, retaining almost 80% of its initial performance after operating at 20 mA/cm2 for 350 min. This work provides fundamental evidence that this novel alternating interlayer cation 2D perovskite can be a promising and stable photonic emitter.

scholarly journals In Vitro Drug Release, Permeability, and Structural Test of Ciprofloxacin-Loaded Nanofibers

Pharmaceutics ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 556
Author(s):  
Luca Éva Uhljar ◽  
Sheng Yuan Kan ◽  
Norbert Radacsi ◽  
Vasileios Koutsos ◽  
Piroska Szabó-Révész ◽  
...  
Keyword(s):  
Amorphous State ◽  
Physical Mixture ◽  
Water Soluble ◽  
Vinyl Pyrrolidone ◽  
Amorphous Solid Dispersion ◽  
Release Mechanism ◽  
Dissolution Studies ◽  
In Vitro Diffusion ◽  
Poly Vinyl Pyrrolidone

Nanofibers of the poorly water-soluble antibiotic ciprofloxacin (CIP) were fabricated in the form of an amorphous solid dispersion by using poly(vinyl pyrrolidone) as a polymer matrix, by the low-cost electrospinning method. The solubility of the nanofibers as well as their in vitro diffusion were remarkably higher than those of the CIP powder or the physical mixture of the two components. The fiber size and morphology were optimized, and it was found that the addition of the CIP to the electrospinning solution decreased the nanofiber diameter, leading to an increased specific surface area. Structural characterization confirmed the interactions between the drug and the polymer and the amorphous state of CIP inside the nanofibers. Since the solubility of CIP is pH-dependent, the in vitro solubility and dissolution studies were executed at different pH levels. The nanofiber sample with the finest morphology demonstrated a significant increase in solubility both in water and pH 7.4 buffer. Single medium and two-stage biorelevant dissolution studies were performed, and the release mechanism was described by mathematical models. Besides, in vitro diffusion from pH 6.8 to pH 7.4 notably increased when compared with the pure drug and physical mixture. Ciprofloxacin-loaded poly(vinyl pyrrolidone) (PVP) nanofibers can be considered as fast-dissolving formulations with improved physicochemical properties.

Poly(N-isopropylacrylamide)-block-poly(vinyl pyrrolidone) block copolymer networks: Synthesis and rapid thermoresponse of hydrogels

Polymer ◽  
2013 ◽  
Vol 54 (4) ◽  
pp. 1370-1380 ◽  
Author(s):  
Houluo Cong ◽  
Lei Li ◽  
Sixun Zheng
Keyword(s):  
Block Copolymer ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Pyrrolidone

Effect of Additives on the Formation of SmCo Magnetic Nanoparticles by Chemical Synthesis

2014 ◽  
Vol 809-810 ◽  
pp. 9-16 ◽  
Author(s):  
Jian Jun Tian
Keyword(s):  
Magnetic Nanoparticles ◽  
Vinyl Pyrrolidone ◽  
Polyol Synthesis ◽  
High Coercivity ◽  
Preparation Process ◽  
Effect Of Additives ◽  
Dispersing Agent ◽  
Base Solution ◽  
Poly Vinyl Pyrrolidone ◽  
Inorganic Precursors

Monodispersed magnetic SmCo nanoparticles have been prepared by polyol synthesis using non-toxic inorganic precursors (nitrates). The effect of the additives of NaOH, HNO3, CH3COOH and poly vinyl pyrrolidone (PVP) on the formation of SmCo nanoparticles is studied in this paper. The results indicate that base solution can boost the reduction of Co while acid solution is helpful for the formation of SmCo due to decreasing the reduction velocity of Co. CH3COOH is appropriate additive for the synthesis of SmCo nanoparticles, but more addition of CH3COOH will result in the emergence of CoC2 phase and decrease the coercivity of the resultants. The additive of PVP not only is a dispersing agent, but can prevent them from oxidating during preparation process. The SmCo nanoparticles with a size of 5-8 nm have the ferromagnetic properties of high coercivity (>1000 Oe).

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