Numerical analysis of film-loaded silicon nanowire optical rectangular waveguide: an effective optical sensing

Micro & nano letters

article

Ritu Raj Singh¹  Vishnu Priye¹ 

[1] Department of Electronics, Indian Institute of Technology (Indian School of Mines)

关键词: refractive index;    elemental semiconductors;    silicon;    finite element analysis;    rectangular waveguides;    nanowires;    silicon-on-insulator;    integrated optics;    nanophotonics;    optical sensors;    nanosensors;    semiconductor thin films;    thin film sensors;    optical waveguide theory;    Si;    SiO2;    size 220.0 nm;    waveguide sensitivity;    confinement factor;    guiding phenomena;    finite-element method;    optimised dimension;    low refractive indexed gapping region;    photonic integrated circuits;    SiO2 substrate;    film-loaded silicon nanowire optical rectangular waveguide;    silicon-on-insulator platform;    subwavelength waveguide;    effective optical sensing;    numerical analysis;    optical sensing element;    standard 220 nm silicon height technology;    silicon nanowire waveguides;    silicon film;   

DOI  :  10.1049/mnl.2018.0140

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Silymarin (SM) is a plant extract obtained from Silybum marianum( milk thistle) . It is class II type drug according to  Biopharmaceutics Classification System with low bioavailability due to its low solubility. Micro/nanonization during crystallization, surface modification and crystal structure modification may improve the dissolution rate of poorly water-soluble drugs. The aim of this study was to increase the water solubility and dissolution rate of SM by in-situ micronization using solvent change either by stirring or ultrasonic method. Stabilizers like Gelatin, PVP-K30, HPMC15, Pulullan were used to stabilize the prepared ultrafine crystals. Effect of type and concentration of hydrophilic polymer, solvent: antisolvent volume ratio and the effect of ultrasonic irradiation were studied. The prepared  microcrystals were evaluated for their %yield,  water solubility, crystals structure by XRD,DSC, and SEM. Particle size and  dissolution rate were also tested . Silymarin microcrystals prepared by ultrasonic method and stabilized by 0.1%gelatin using 1:2 solvent: anti-solvent volume ratio showed the best results with particle size reduction from mean diameter of 1.5µm (untrated silymarin) to 0.43µm with uniform morphology and enhanced solubility and  dissolution.

【 授权许可】

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