Cover Image

Shape and size analysis of calcium alginate particles produced through extrusion method

Alginate is the most widely used biopolymer for bioencapsulation because it can form thermally stable and biocompatible gel particles in the presence of calcium cation by using simple extrusion method. Particles which are spherical in shape and uniform in size are highly desirable in many applicatio...

Full description

Saved in:
Bibliographic Details
Main Author: Lee, Boon Beng
Format: Thesis
Language:English
English
Published: 2008
Subjects:
TP1080-1185 Polymers and polymer manufacture
Online Access:https://eprints.ums.edu.my/id/eprint/41841/1/24%20PAGES.pdf
https://eprints.ums.edu.my/id/eprint/41841/2/FULLTEXT.pdf
https://eprints.ums.edu.my/id/eprint/41841/
Tags: Add Tag
No Tags, Be the first to tag this record!
id my.ums.eprints.41841
record_format eprints
spelling my.ums.eprints.418412024-12-05T03:50:27Z https://eprints.ums.edu.my/id/eprint/41841/ Shape and size analysis of calcium alginate particles produced through extrusion method Lee, Boon Beng TP1080-1185 Polymers and polymer manufacture Alginate is the most widely used biopolymer for bioencapsulation because it can form thermally stable and biocompatible gel particles in the presence of calcium cation by using simple extrusion method. Particles which are spherical in shape and uniform in size are highly desirable in many applications. Formation of particles with these characteristics is influenced by a combination of process variables such as solution properties and operation conditions. The primary objective of this work is to study the inter-relationship of process variables on shape and size of calcium-alginate particles produced through extrusion-dripping method given that no such systematic study has been reported in the past. The first part of this research involved measurement of alginate solutions density, viscosity and surface tension. The second part involved shape and size analysis of travelling Na-alginate solution droplets and calcium-alginate particles produced under various process conditions. Dimensionless number groups were used to develop the inter-relationships between the process variables. The final part involved development of a mathematical model for prediction of particle size. In this research, it was found that the surface tension decreased as the concentration of alginate solution increased. Conversely, the density and viscosity of alginate solution increased as the concentration of alginate solution increased. For shape analysis, the spherity of calcium-alginate particle was found to be affected by the combined influence of the solution properties, the collecting distance and the droplet size. Spherical particle could only be formed when OhI > 0.25. Furthermore, the shape of Ca-alginate particles could be typically distinguished into three phases along the collecting distance. The transition points of the distance between the phases can be described by a shape diagram which is a plot of the impact Reynolds number (ReI) and the impact Ohnesorge number (OhI) of the Na-alginate solution drops at the point of liquid-liquid impact. The diagram also reveals a clear operating region and the process limits within which spherical Ca-alginate particles could be formed. In term of particle size, an overall size reduction factor (K) was introduced to modify the size predicted from Tate’s law by taking into account the Na-alginate solution droplet correction factor (kHB) and shrinkage factor (kS). The Na-alginate solution droplet correction factor (kHB) was independent of the Na-alginate solution physical properties but was dependent on the tip size. It could be described by a quadratic equation within the experimental limits. The shrinkage factor (ks) was found to be affected by the M/G ratio of alginate. The size reduction factor (K) varied from 0.73-0.85 under the experimental conditions and the size prediction model was found to correlate well with the experimental data with an average absolute deviation of less than 5%. In short, the shape diagram and prediction models can be used to produce spherical Ca-alginate particles with desirabed size. 2008 Thesis NonPeerReviewed text en https://eprints.ums.edu.my/id/eprint/41841/1/24%20PAGES.pdf text en https://eprints.ums.edu.my/id/eprint/41841/2/FULLTEXT.pdf Lee, Boon Beng (2008) Shape and size analysis of calcium alginate particles produced through extrusion method. Masters thesis, Universiti Malaysia Sabah.
institution Universiti Malaysia Sabah
building UMS Library
collection Institutional Repository
continent Asia
country Malaysia
content_provider Universiti Malaysia Sabah
content_source UMS Institutional Repository
url_provider http://eprints.ums.edu.my/
language English
English
topic TP1080-1185 Polymers and polymer manufacture
spellingShingle TP1080-1185 Polymers and polymer manufacture
Lee, Boon Beng
Shape and size analysis of calcium alginate particles produced through extrusion method
description Alginate is the most widely used biopolymer for bioencapsulation because it can form thermally stable and biocompatible gel particles in the presence of calcium cation by using simple extrusion method. Particles which are spherical in shape and uniform in size are highly desirable in many applications. Formation of particles with these characteristics is influenced by a combination of process variables such as solution properties and operation conditions. The primary objective of this work is to study the inter-relationship of process variables on shape and size of calcium-alginate particles produced through extrusion-dripping method given that no such systematic study has been reported in the past. The first part of this research involved measurement of alginate solutions density, viscosity and surface tension. The second part involved shape and size analysis of travelling Na-alginate solution droplets and calcium-alginate particles produced under various process conditions. Dimensionless number groups were used to develop the inter-relationships between the process variables. The final part involved development of a mathematical model for prediction of particle size. In this research, it was found that the surface tension decreased as the concentration of alginate solution increased. Conversely, the density and viscosity of alginate solution increased as the concentration of alginate solution increased. For shape analysis, the spherity of calcium-alginate particle was found to be affected by the combined influence of the solution properties, the collecting distance and the droplet size. Spherical particle could only be formed when OhI > 0.25. Furthermore, the shape of Ca-alginate particles could be typically distinguished into three phases along the collecting distance. The transition points of the distance between the phases can be described by a shape diagram which is a plot of the impact Reynolds number (ReI) and the impact Ohnesorge number (OhI) of the Na-alginate solution drops at the point of liquid-liquid impact. The diagram also reveals a clear operating region and the process limits within which spherical Ca-alginate particles could be formed. In term of particle size, an overall size reduction factor (K) was introduced to modify the size predicted from Tate’s law by taking into account the Na-alginate solution droplet correction factor (kHB) and shrinkage factor (kS). The Na-alginate solution droplet correction factor (kHB) was independent of the Na-alginate solution physical properties but was dependent on the tip size. It could be described by a quadratic equation within the experimental limits. The shrinkage factor (ks) was found to be affected by the M/G ratio of alginate. The size reduction factor (K) varied from 0.73-0.85 under the experimental conditions and the size prediction model was found to correlate well with the experimental data with an average absolute deviation of less than 5%. In short, the shape diagram and prediction models can be used to produce spherical Ca-alginate particles with desirabed size.
format Thesis
author Lee, Boon Beng
author_facet Lee, Boon Beng
author_sort Lee, Boon Beng
title Shape and size analysis of calcium alginate particles produced through extrusion method
title_short Shape and size analysis of calcium alginate particles produced through extrusion method
title_full Shape and size analysis of calcium alginate particles produced through extrusion method
title_fullStr Shape and size analysis of calcium alginate particles produced through extrusion method
title_full_unstemmed Shape and size analysis of calcium alginate particles produced through extrusion method
title_sort shape and size analysis of calcium alginate particles produced through extrusion method
publishDate 2008
url https://eprints.ums.edu.my/id/eprint/41841/1/24%20PAGES.pdf
https://eprints.ums.edu.my/id/eprint/41841/2/FULLTEXT.pdf
https://eprints.ums.edu.my/id/eprint/41841/
_version_ 1817843847895449600
score 13.222552

Similar Items