Preparation and properties of wet-spun microcomposite filaments from cellulose nanocrystals and alginate using a microfluidic device

BioResources ◽  
2021 ◽  
Vol 16 (3) ◽  
pp. 5780-5793
Author(s):  
Ji-Soo Park ◽  
Chan-Woo Park ◽  
Song-Yi Han ◽  
Eun-Ah Lee ◽  
Azelia Wulan Cindradewi ◽  
...  
Keyword(s):  
Tensile Properties ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Microfluidic Device ◽  
Cellulose Nanocrystals ◽  
Average Diameter ◽  
Coagulation Bath ◽  
Al Content ◽  
Orientation Index ◽  
Cacl2 Solution

Cellulose nanocrystals (CNCs) were wet-spun in a coagulation bath for the fabrication of microfilaments, and the effect of sodium alginate (AL) addition on the wet-spinnability and properties of the microcomposite filament was investigated. The CNC suspension exhibited excellent wet-spinnability in calcium chloride (CaCl2) solution, and the addition of AL in CNC suspension resulted in the enhancement of the wet-spinnability of CNCs. As the AL content increased from 3% to 10%, the average diameter of the microcomposite filament decreased, and its tensile properties deteriorated. The increased spinning rate caused an increase in the orientation index of CNCs, resulting in an improvement in the tensile properties of the microcomposite filament.

scholarly journals Wet-Spun Composite Filaments from Lignocellulose Nanofibrils/Alginate and Their Physico-Mechanical Properties

Polymers ◽  
2021 ◽  
Vol 13 (17) ◽  
pp. 2974
Author(s):  
Ji-Soo Park ◽  
Song-Yi Han ◽  
Rajkumar Bandi ◽  
Eun-Ah Lee ◽  
Azelia-Wulan Cindradewi ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Choline Chloride ◽  
Cellulose Nanofibrils ◽  
Deep Eutectic Solvent ◽  
Average Diameter ◽  
Al Content ◽  
Pure Cellulose ◽  
Orientation Index ◽  
Lignocellulose Nanofibrils ◽  
Cacl2 Solution

Lignocellulose nanofibrils (LCNFs) with different lignin contents were prepared using choline chloride (ChCl)/lactic acid (LA), deep eutectic solvent (DES) pretreatment, and subsequent mechanical defibrillation. The LCNFs had a diameter of 15.3–18.2 nm, which was similar to the diameter of commercial pure cellulose nanofibrils (PCNFs). The LCNFs and PCNFs were wet-spun in CaCl2 solution for filament fabrication. The addition of sodium alginate (AL) significantly improved the wet-spinnability of the LCNFs. As the AL content increased, the average diameter of the composite filaments increased, and the orientation index decreased. The increase in AL content improved the wet-spinnability of CNFs but deteriorated the tensile properties. The increase in the spinning rate resulted in an increase in the orientation index, which improved the tensile strength and elastic modulus.

scholarly journals Fabrication of Microparticles with Front–Back Asymmetric Shapes Using Anisotropic Gelation

Micromachines ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 1121
Author(s):  
Dongkyu Lee ◽  
Hiroyuki Kitahata ◽  
Hiroaki Ito
Keyword(s):  
Velocity Field ◽  
Sodium Alginate ◽  
Stagnation Point ◽  
Calcium Chloride ◽  
Aqueous Phase ◽  
Microfluidic Device ◽  
Organic Phase ◽  
Fabrication Technique ◽  
Flow Focusing ◽  
Asymmetric Shape

Droplet-based microfluidics is a powerful tool for producing monodispersed micrometer-sized droplets with controlled sizes and shapes; thus, it has been widely applied in diverse fields from fundamental science to industries. Toward a simpler method for fabricating microparticles with front–back asymmetry in their shapes, we studied anisotropic gelation of alginate droplets, which occurs inside a flow-focusing microfluidic device. In the proposed method, sodium alginate (NaAlg) aqueous phase fused with a calcium chloride (CaCl2) emulsion dispersed in the organic phase just before the aqueous phase breaks up into the droplets. The fused droplet with a front–back asymmetric shape was generated, and the asymmetric shape was kept after geometrical confinement by a narrow microchannel was removed. The shape of the fused droplet depended on the size of prefused NaAlg aqueous phase and a CaCl2 emulsion, and the front–back asymmetry appeared in the case of the smaller emulsion size. The analysis of the velocity field inside and around the droplet revealed that the stagnation point at the tip of the aqueous phase also played an important role. The proposed mechanism will be potentially applicable as a novel fabrication technique of microparticles with asymmetric shapes.

scholarly journals Investigation of the Shear Thickening Fluid Encapsulation in an Orifice Coagulation Bath

Polymers ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 519 ◽  
Author(s):  
Xing Liu ◽  
Jun-Li Huo ◽  
Ting-Ting Li ◽  
Hao-Kai Peng ◽  
Jia-Horng Lin ◽  
...  
Keyword(s):  
Sodium Alginate ◽  
Mass Concentration ◽  
Chloride Concentration ◽  
Optimal Solution ◽  
Shear Thickening ◽  
Average Diameter ◽  
Coagulation Bath ◽  
Shear Thickening Fluid ◽  
Preparation Conditions ◽  
Alginate Concentration

The orifice coagulation bath method is proposed to encapsulate shear thickening fluid (STF) to form STF capsules, in an attempt to improve the combination of STF and the matrix as well as strengthen the flexibility and stability of the STF composites. By varying the calcium chloride concentration (10, 20 mg/ml), sodium alginate concentration (5, 7, 10 mg/ml) and the surfactant dosage (10%, 20%, 30%), optimal preparation conditions were studied, considering the capsule strength and encapsulation rate. The capsules were also characterized using a scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR) and a thermogravimetric analyzer (TGA). The results show that the optimal solution for the preparation of the capsules is composed of 30% surfactant, 10 mg/ml mass concentration of CaCl2, and 10 mg/ml mass concentration of sodium alginate. The rough surface and porous interior was observed by SEM. The average diameter of the capsules was 1.93 mm. The TGA curves indicate an improvement on the capsule thermal stability. This study thus provides a promising STF capsule preparation method.

scholarly journals Conservation, Regeneration and Genetic Stability of Regenerants from Alginate-Encapsulated Shoot Explants of Gardenia jasminoides Ellis

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1666
Author(s):  
Stefanos Hatzilazarou ◽  
Stefanos Kostas ◽  
Theodora Nendou ◽  
Athanasios Economou
Keyword(s):  
Sodium Alginate ◽  
Calcium Chloride ◽  
Genetic Stability ◽  
Nutrient Medium ◽  
Shoot Tips ◽  
Mother Plant ◽  
Short Term ◽  
Alginate Encapsulation ◽  
Gardenia Jasminoides ◽  
Regeneration Response

The present study demonstrates the potential of the alginate encapsulation of shoot tips and nodal segments of Gardenia jasminoides Ellis, the short-term cold storage of artificial seeds and subsequent successful conversion to desirable, uniform and genetically stable plantlets. Shoot tips and first-node segments below them, derived from shoots of in vitro cultures, responded better than second-to-fourth-node segments on agar-solidified Murashige and Skoog (MS) nutrient medium and thus, they were used as explants for alginate encapsulation. Explant encapsulation in 2.5% sodium alginate in combination with 50 mM of calcium chloride resulted in the production of soft beads, while hardening in 100 mM of calcium chloride formed firm beads of uniform globular shape, suitable for handling. The addition of liquid MS nutrient medium in the sodium alginate solution doubled the subsequent germination response of the beads. The maintenance of alginate beads under light favored their germination response compared to maintenance in darkness. Encapsulated shoot tip explants of gardenia, which were stored at 4 °C for 4, 8 or 12 weeks, showed a gradual decline in their regeneration response (73.3, 68.9, 53.3%, respectively), whereas, non-encapsulated explants (naked), stored under the same time durations of cold conditions, exhibited a sharp decline in regeneration response up to entirely zeroing (48.9, 11.1, 0.0%, respectively). Shoots, derived from 12-week cold-stored encapsulated explants, were easily rooted in solid MS nutrient medium with the addition of 0.5 μM of Indole-3-acetic acid (IAA) and after transplantation of the rooted plantlets individually to pots containing a peat–perlite (3:1, v/v) substrate, they were successfully acclimatized in the greenhouse under the gradual reduction of 75 or 50% shading with survival rates of 95–100%. The genetic stability of the acclimatized plantlets was assessed and compared with the mother plant using inter simple sequence repeat (ISSR) markers. ISSR analysis confirmed that all regenerated plantlets were genetically identical to the mother plant. This procedure of artificial seed production could be useful for the short-term storage of germplasm and the production of genetically identical and stable plants as an alternative method of micropropagation in Gardenia jasminoides.

scholarly journals DESIGN AND EVALUATION OF CONTROLLED-RELEASE OCULAR INSERTS OF BRIMONIDINE-TARTRATE AND TIMOLOL MALEATE

2016 ◽  
Vol 9 (1) ◽  
pp. 79 ◽  
Author(s):  
Preethi G. B. ◽  
Prashanth Kunal
Keyword(s):  
Controlled Release ◽  
Drug Release ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Release Kinetics ◽  
Water Soluble ◽  
Moisture Loss ◽  
Timolol Maleate ◽  
Brimonidine Tartrate

<p><strong>Objective: </strong>The current work was attempted to formulate and evaluate a controlled-release matrix-type ocular inserts containing a combination of brimonidine tartrate and timolol maleate, with a view to sustain the drug release in the cul-de-sac of the eye.<strong></strong></p><p><strong>Methods: </strong>Initially, the infrared studies were done to determine the drug–polymer interactions. Sodium alginate-loaded ocuserts were prepared by solvent casting technique. Varying the concentrations of polymer—sodium alginate, plasticizer—glycerine, and cross-linking agent—calcium chloride by keeping the drug concentration constant, made a total of nine formulations. These formulations were evaluated for its appearance, drug content, weight uniformity, thickness uniformity, percentage moisture loss, percentage moisture absorption, and <em>in vitro </em>release profile of the ocuserts. Finally, accelerated stability studies and the release kinetics were performed on the optimised formulation.<strong></strong></p><p><strong>Results: </strong>It was perceived that polymer, plasticizer, and calcium chloride had a significant influence on the drug release. The data obtained from the formulations showed that formulation—F9 was the optimised formulation, which exhibited better drug release. The release data of the optimised formulation tested on the kinetic models revealed that it exhibited first-order release kinetics. <strong></strong></p><p><strong>Conclusion: </strong>It can be concluded that a natural bioadhesive hydrophilic polymer such as sodium alginate can be used as a film former to load water soluble and hydrophilic drugs like brimonidine tartrate and timolol maleate. Among all formulations, F9 with 400 mg sodium alginate, 2% calcium chloride and 60 mg glycerin were found to be the most suitable insert in terms of appearance, ease of handling, thickness, <em>in vitro</em> drug release and stability.</p>

scholarly journals Micropipette-Based Microfluidic Device for Monodisperse Microbubbles Generation

Micromachines ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 387
Author(s):  
Carlos Toshiyuki Matsumi ◽  
Wilson José da Silva ◽  
Fábio Kurt Schneider ◽  
Joaquim Miguel Maia ◽  
Rigoberto E. M. Morales ◽  
...  
Keyword(s):  
Electric Fields ◽  
Microfluidic Device ◽  
Soft Lithography ◽  
Low Cost ◽  
Characteristic Curve ◽  
Microfluidic Devices ◽  
Average Diameter ◽  
Internal Diameter ◽  
Medical Diagnostic ◽  
Average Size

Microbubbles have various applications including their use as carrier agents for localized delivery of genes and drugs and in medical diagnostic imagery. Various techniques are used for the production of monodisperse microbubbles including the Gyratory, the coaxial electro-hydrodynamic atomization (CEHDA), the sonication methods, and the use of microfluidic devices. Some of these techniques require safety procedures during the application of intense electric fields (e.g., CEHDA) or soft lithography equipment for the production of microfluidic devices. This study presents a hybrid manufacturing process using micropipettes and 3D printing for the construction of a T-Junction microfluidic device resulting in simple and low cost generation of monodisperse microbubbles. In this work, microbubbles with an average size of 16.6 to 57.7 μm and a polydispersity index (PDI) between 0.47% and 1.06% were generated. When the device is used at higher bubble production rate, the average diameter was 42.8 μm with increased PDI of 3.13%. In addition, a second-order polynomial characteristic curve useful to estimate micropipette internal diameter necessary to generate a desired microbubble size is presented and a linear relationship between the ratio of gaseous and liquid phases flows and the ratio of microbubble and micropipette diameters (i.e., Qg/Ql and Db/Dp) was found.

scholarly journals STANDARDIZATION OF MEDIUM FOR SYNTHETIC SEED GERMINATION OF SALVIA SCLAREA L.

2015 ◽  
Vol 2 (1) ◽  
pp. 118-120
Author(s):  
Durgha H ◽  
Ramya G ◽  
Gogul Ramanth M ◽  
Thirugnanasampandan R
Keyword(s):  
Seed Germination ◽  
Sodium Alginate ◽  
Calcium Chloride ◽  
Multiple Shoot ◽  
Nodal Explants ◽  
Synthetic Seed ◽  
Ms Medium ◽  
Shoot Induction ◽  
Multiple Shoot Induction ◽  
Salvia Sclarea

Young nodal explants (0.5-1cm) of Salvia sclarea L. was used for synthetic seed preparation.Synthetic seeds were prepared using 5% sodium alginate and 1.11% calcium chloride. Seed germination was observed on MS medium fortified with 1.4µM GA3+4.4µM BA after twenty days of culture. Further multiple shoot induction was observed after fifteen days of shootinduction.

Sign in / Sign up

Export Citation Format

Share Document