Application of Alginate in Water Treatment and Drug Delivery Systems

Author: Wafa Algothmi

Algothmi, Wafa, 2015 Application of Alginate in Water Treatment and Drug Delivery Systems, Flinders University, School of Chemical and Physical Sciences

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Abstract

This thesis covers both the use of Ca-Alg2 hydrogels in water treatment and drug delivery system. Ca-Alg2 and Ca-Alg2/GO gel bead adsorbents fabricated for the removal of Cu2+ ions from aqueous solution. The influence of the use of different adsorbent doses, Cu2+ concentrations and contact time on the adsorption process was demonstrated that the larger surface area of GO and oxygen containing functional groups on the GO surface plays a strong role in increasing the adsorption capacity of Ca-Alg2. Chapter two discusses the loading of RB, Rubpy and CPT into Ca-Alg2 hydrogel using the in situ addition method. The influence of the pH of the released medium affected on the release of both of dye and drug from Ca-Alg2 hydrogel. The molecular weight and the charge of the dye or drug play an important role in the releas process from Ca-Alg2 hydrogel. Furthermore, the release kinetic studies for both of dye and drug revealed that the release mechanisms of the three molecules at pH ~ 2.4 occurred via Fickian diffusion and Case II transport. However, at pH ~ 7.4, the release mechanisms was an anomalous transport. This thesis also focused on synthesis and characterisation of β-CD-g-Alg. The characterisation of the CPT inclusion complexes (CPT/β-CD and CPT/β-CD-g-Alg) confirmed that the inclusion complexes were produced, and the results indicated that the amino quinoline group for CPT molecule is included into the β-CD cavity. Furthermore, the thermal analysis shows that the ratio of Na-Alg to β-CD appears to be 2:1. The last section details the release profile of CPT from both inclusion complexes using the dialysis technique, and Fick's second law was used to analyse the release data. It was found that β-CD prolonged the release of CPT with initial burst release and reached the equilibrium after 9 days. However, the release of CPT from the CPT/β-CD-g-Alg inclusion complex did not show the initial burst release and the equilibrium was reached after 13 days. This result indicates that Na-Alg increased the solubility of CPT/β-CD inclusion complex and enhanced the formation of CPT/β-CD.

Keywords: Sodium alginate,Na-Alg,alginic acid,H-Alg,polysaccharide,guluronic acid,mannuronic acid,copolymer,ionotropic gels,cross-linking,Egg-box,junction zone,membrane,diffuse,diffusion method,internal method,gelation,intermolecular,interamolecular,anionic hydrogels,chains,sp2-bonding,graphite oxide,water treatment,graphene oxide,GO,calcium alginate,Ca-Alg2,Ca-Alg2/GO,beads,dropping method,encapsulated,naphthalene,weight loss,pore size,copper,heavy metal,divalent metal,adsorption,adsorbent,equilibrium,agitation time,contact time,ion exchange,homopolymeric,Langmuir equation,adsorption capacity,adsorption percentage,adsorption sites,removal efficiency,chelation,pseudo-second-order,adsorption kinetics,rose Bengal,RB,Tris (2,2-bipyridyl) dichlororuthenium(II)hexahydrate,Rubpy,camptothecin,drug,CPT,hydrogel,release,addition method,Fluorescence,UV-Vis absorption,lactone form,carboxylate form,cross-linking,Tris buffer,fractional release,swelling,shrinkage,Fick's second law,electrostatic attraction,electrostatic repulsion,positive charged,negative charged,hydrophilic,hydrophobic,diffusion coefficients,protonated,sol-gel transformation,delivery system,beta-cyclodextrin,camptotheca acuminate,active,inactive,inclusion complex,host-guest complex,cavity,guest molecule,chemical shifts,controlled,prolonged,sustained
Subject: Chemistry thesis

Thesis type: Doctor of Philosophy
Completed: 2015
School: School of Chemical and Physical Sciences
Supervisor: Prof. Amanda Ellis