Thiol–ene addition enables tailored synthesis of poly(2‐oxazoline)‐ graft ‐poly(vinyl pyrrolidone) copolymers for binder jetting 3D printing

2020 ◽  
Vol 69 (10) ◽  
pp. 902-911 ◽  
Author(s):  
Emily M Wilts ◽  
Timothy E Long
Keyword(s):  
3D Printing ◽  
Vinyl Pyrrolidone ◽  
Poly Vinyl Pyrrolidone ◽  
Binder Jetting ◽  
Ene Addition

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 Printability and Setting Time of CSA Cement with Na2SiO3 and Gypsum for Binder Jetting 3D Printing

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2811
Author(s):  
Okpin Na ◽  
Kangmin Kim ◽  
Hyunjoo Lee ◽  
Hyunseung Lee
Keyword(s):  
3D Printing ◽  
Sodium Silicate ◽  
Setting Time ◽  
Sodium Silicate Solution ◽  
Preliminary Test ◽  
Silicate Solution ◽  
Calcium Sulfoaluminate Cement ◽  
Calcium Sulfoaluminate ◽  
Parametric Studies ◽  
Binder Jetting

The purpose of this study is to optimize the composition of CSA (calcium sulfoaluminate) cement with sodium silicate (Na2SiO3) and gypsum for binder jetting 3D printing. The preliminary test was carried out with an applicator to decide the proper thickness of one layer before using the 3D printer. A liquid binder was then selected to maintain the shape of the particles. Based on the results, the optimal mixture of dry materials and a liquid activator was derived through various parametric studies. For dry materials, the optimum composition of CSA cement, gypsum, and sand was suggested, and the liquid activator made with sodium silicate solution and VMA (viscosity modified agent) were selected. The setting time with gypsum and sodium silicate was controlled within 30 s. In case of the delayed setting time and the rapid setting mixture, the jetting line was printed thicker or thinner and the accuracy of the printout was degraded. In order to adjust the viscosity of the liquid activator, 10% of the VMA was used in 35% of sodium silicate solution and the viscosity of 200–400 cP was suitable to be sprayed from the nozzle. With this optimal mixture, a prototype of atypical decorative wall was printed, and the compressive strength was measured at about 7 MPa.

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 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.

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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