Non-Fickian Solvent Diffusion in a Solid with Large Dilatation

2013 ◽  
pp. 207-222
Keyword(s):  
Solvent Diffusion

Solvent diffusion mechanism of PMMA/ acetone coated glass fiber fabric during curing process

2021 ◽  
pp. 152808372110362
Author(s):  
Zhenrong Zheng ◽  
Yuejiao Bi ◽  
Lihuan Tong ◽  
Yalan Liu
Keyword(s):  
Glass Fiber ◽  
Diffusion Mechanism ◽  
Coating Film ◽  
Curing Process ◽  
Curing Time ◽  
Solvent Concentration ◽  
Solvent Diffusion ◽  
Coated Glass ◽  
Drying Model ◽  
Fiber Fabric

Fabric it is not an impermeable substrate because of fiber porosity. To study the solvent diffusion mechanism of coated fabric in the curing process, the drying model of PMMA/acetone coated glass fiber fabric was established. This drying model was verified by confocal Raman spectroscopy. Finally, the impact of fabric structure, thickness and porosity on the solvent diffusion process in coated fabrics was studied by the model. It was shown that the predicted solvent concentrations by the model were consistent with the experimental values. This model can be used to quantitatively calculate the solvent concentration at any position and at any time inside the coating film during the drying process. Moreover, it can also predict the curing time and residual solvent concentration of the coating fabric required to reach drying equilibrium. Compared with coated 3/1 twill, 5/3 satin and 2/1 twill, the solvent diffusion of coated plain fabric was faster during curing. Under the same environmental conditions, the thinner the fabric was and the greater the porosity was, the shorter the curing time was. The fitting equations for fabric thickness, fabric porosity and drying time were obtained, which can provide a theoretical guidance for the preparation, performance research and drying conditions optimization of PMMA coated textile materials.

Solid lipid nanoparticles prepared by solvent diffusion method in a nanoreactor system

2008 ◽  
Vol 61 (2) ◽  
pp. 132-137 ◽  
Author(s):  
Hong Yuan ◽  
Ling-Fei Huang ◽  
Yong-Zhong Du ◽  
Xiao-Ying Ying ◽  
Jian You ◽  
...  
Keyword(s):  
Solid Lipid Nanoparticles ◽  
Lipid Nanoparticles ◽  
Diffusion Method ◽  
Solvent Diffusion ◽  
Solid Lipid

scholarly journals PREPARATION, CHARACTERIZATION AND EVALUATION OF POLY (LACTIDE –CO –GLYCOLIDE) MICROSPHERES FOR THE CONTROLLED RELEASE OF ZIDOVUDINE

2017 ◽  
Vol 9 (12) ◽  
pp. 70 ◽  
Author(s):  
Seema Kohli ◽  
Abhisek Pal ◽  
Suchit Jain
Keyword(s):  
Particle Size ◽  
Controlled Release ◽  
Double Emulsion ◽  
Entrapment Efficiency ◽  
Diffusion Method ◽  
Average Particle ◽  
Plga Microspheres ◽  
Good Reproducibility ◽  
Solvent Diffusion ◽  
Emulsion Solvent Diffusion Method

Objective: The purpose of this research work was to develop and evaluate microspheres appropriate for controlled release of zidovudine (AZT).Methods: The AZT loaded polylactide-co-glycolide (PLGA) microspheres were prepared by W/O/O double emulsion solvent diffusion method. Compatibility of drug and polymer was studied by Fourier-transform infrared spectroscopy (FTIR). The influence of formulation factors (drug: polymer ratio, stirring speed, the concentration of surfactant) on particle size encapsulation efficiency and in vitro release characteristics of the microspheres was investigated. Release kinetics was studied and stability study was performed as per ICH guidelines.Results: Scanning electron microscopy (SEM) images show good reproducibility of microspheres from different batches. The average particle size was in the range of 216-306 μm. The drug-loaded microspheres showed 74.42±5.08% entrapment efficiency. The cumulative percentage released in phosphate Buffer solution (PBS) buffer was found to be 55.32±5.89 to 74.42±5.08 %. The highest regressions (0.981) were obtained for zero order kinetics followed by Higuchi (0.968) and first order (0.803).Conclusion: Microsphere prepared by double emulsion solvent diffusion method was investigated and the results revealed that 216-306 μm microsphere was successfully encapsulated in a polymer. FT-IR analysis, entrapment efficiency and SEM Studies revealed the good reproducibility from batch to batch. The microspheres were of an appropriate size and suitable for oral administration. Thus the current investigation show promising results of PLGA microspheres as a matrix for drug delivery and merit for In vivo studies for scale up the technology.

scholarly journals Suggested Procedures for the Reproducible Synthesis of Poly(d,l-lactideco-glycolide) Nanoparticles Using the Emulsification Solvent Diffusion Platform

2018 ◽  
Vol 14 (5) ◽  
pp. 448-453 ◽  
Author(s):  
Shadabul Haque ◽  
Ben J. Boyd ◽  
Michelle P. McIntosh ◽  
Colin W. Pouton ◽  
Lisa M. Kaminskas ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Water Solubility ◽  
Plga Nanoparticles ◽  
Diffusion Method ◽  
Salting Out ◽  
Solvent Diffusion ◽  
Zeta Potentials ◽  
Highly Sensitive ◽  
Nanoparticulate Systems ◽  
Uniform Particle Size

Background: Poly(d,l-lactide-co-glycolide) (PLGA) based biodegradable nanoparticles are of key interest for the development of controlled release drug delivery systems and for other biomedical applications. It has been reported that PLGA polymers can be converted into colloidal nanoparticulate systems by various techniques, such as emulsification-diffusion, emulsificationevaporation, interfacial deposition, salting out, dialysis and nanoprecipitation. Emulsificationevaporation with water immiscible solvents including dichloromethane and chloroform has been the preferred method for the synthesis of PLGA nanoparticles due to the low boiling point and limited water solubility of these solvents. We and others, however, have found that when water-immiscible solvents are used for the synthesis of PLGA nanoparticles, particle aggregation, non-uniform particle size and multimodal size distribution are commonly encountered problems. This suggests that the synthesis of PLGA nanoparticles using water immiscible solvents is highly sensitive to small procedural variations that affect overall reproducibility. Objective: This study presents a simple and robust procedure for the preparation of PLGA nanoparticles with very small batch to batch variability (<5% variability in size (z-average) as determined by dynamic light scattering). Results: The results showed that the emulsification solvent diffusion method teamed with partially water-miscible solvents, such as ethyl acetate, is a versatile approach for the preparation of PLGA nanoparticles with highly reproducible sizes (between 50 and 400 nm) and zeta potentials (between - 30 and +30 mV), with relatively narrow polydispersity. Conclusion: Emulsification-diffusion with ethyl acetate is, therefore, a more reliable alternative to several existing procedures for the reproducible and refined synthesis of PLGA nanoparticles.

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