STUDYING THE FORMATION CONDITIONS AND PROPERTIES OF POLYELECTROLYTE COMPLEXES BASED ON CARBOXYMETHYL-CELLULOSE AND POLY-DIALLYL-DIMETHYL-AMMONIUM CHLORIDE
This paper deals with studying the polyelectrolyte complexes based on polysaccharide carboxymethyl-cellulose (CMC) and poly-diallyl-dimethyl-ammonium chloride (PDADMAC). The topicality is related to the fact that, based on the polyelectrolyte complexes of water-soluble polymers, various biomedical materials can be created, such as targeted drug delivery means, biologic substance encapsulation systems, gene therapy substrates, etc. Forming a stable polyelectrolyte complex and changing its composition are reversible processes that depend on some factors, such as polyelectrolyte nature, molecular weight, molecular-weight distribution, ionic strength, electrolytes proportions, and the sequence of mixing the solutions. Therefore, using the turbidimetric titration method for each concentration of polymers CMC and PDADMAC (0.08% and 0.1%), we found the range of molar ratios z(∆z=0.45 for 0.08% and ∆z=0.4 for 0.1% solutions), in which stable aqueous dispersions of the polyelectrolyte PDADMAC-CMC complex are formed. Similarly, for each concentration for polymers CMC and PDADMAC (0.08% and 0.1%), the range of molar ratios (∆z=0.45 for 0.08% and ∆z=0.4 for 0.1% solutions), in which stable aqueous dispersions of the CMC-PDADMAC complex are formed. It is shown that, at the polymer concentrations of above 0.1%, the PDADMAC-CMC and CMC-PDADMAC systems are unstable in terms of aggregate state, and that precipitations are formed. It is found that, for the PDADMAC-CMC system within the range of z=0.4-0.8 at increasing the molar ratios of polyelectrolytes, the particle sizes increase averagely from 100 to 155 nm; while for the CMC-PDADMAC system within the range of z=0.2-0.6 at increasing the molar ratios of polyelectrolytes, the particle sizes increase averagely from 110 to 161 nm. Aggregative stability was investigated in time. Within 4 days from the time of obtaining, the particle sizes change slightly. Therefore, the conditions are defined, in which various types of polyelectrolyte complexes for the CMC-PDADMAC and PDADMAC-CMC systems can exist, which will allow defining the area of their applications and developing the techniques of obtaining various materials based on them.