Preparation of Hydroxypropylcellulose Membranes using Slow Ionotropic Reactions Configured in an Experimental Design

Abstract

This study applied a Face-Centered Central Composite Design to prepare various hydroxypropylcellulose (HPC) membranes using slow ionotropic reactions. After the assessment of various salting-out agents, sodium carbonate was selected as the ideal electrolyte capable of inducing sufficient membrane growth. The factors studied included the concentration of hydroxypropylcellulose [HPC] (1-2%w/v), concentration of salt [Salt] (10-20%w/v) and the salting-out reaction time (SORT) (96-144 hours). The experimental and predicted responses in the design included the measurement of the Brinell Hardness Number (BHN), gel thickness, moisture absorption and membrane erosion. Surface morphological examination revealed that the membranes varied from highly porous to closely packed networks. Statistically, the experimental and predicated response values showed no significant differences (p 0.05) based on a one way ANOVA. A significant decrease in BHN was observed as the [HPC] was increased. This was attributed to an increase in the elasticity of the membrane. The increase in moisture absorption was accompanied by an increase in gel thickness and subsequently an increase in membrane erosion around the peripheral areas of the gel structure. In the case of the [Salt], all response values were reduced above 15%w/v, except in the case of the BHN. In the case of SORT, there was a substantial increase in the responses above 120 hours, except once again for BHN. Above 120 hours the matrix became loose due to extensive infiltration and crystallization of salt ions. The interactions plots indicated that the changes among the different factor levels were found to be significant (p 0.05). The average p-values for the changes between levels for each response were: BHN - p 0.035, moisture absorption - p 0.029, gel thickness - p 0.011, and erosion - p 0.042. This technology may be applicable in the development of membrane scaffolds for interconnecting tissues via their role in cell seeding, adhesion and regeneration.