Zur Kenntnis der lyophilen Kolloide

Holleman, L. W. J.; Jong, H. G. Bungenberg de; Modderman, R. S. Tjaden

doi:10.1007/bf02557071

Cited by 14 publications

(1 citation statement)

References 9 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The initial reference to interpolymer complexes (IPCs) (also referred to as polymerpolymer complexes in some sources) can be traced back to the research documented in [1]. Subsequently, Bungenberg de Jong extended these investigations, as indicated in references [2][3][4][5]. The systematic studies in this field were first undertaken by Liquori, as evidenced by works [6,7].…”

Section: Introductionmentioning

confidence: 99%

Interpolymer Complexes Based on Cellulose Ethers: Application

Keldibekova,

Suleimenova,

Nurgozhina

et al. 2023

Polymers

View full text Add to dashboard Cite

Interpolymer complexes based on cellulose ethers have gained significant interest in recent years due to their versatile applications. These complexes are formed by combining different polymers through non-covalent interactions, resulting in stable structures. This article provides an overview of the various fields where IPCs based on cellulose ethers find application. IPCs based on cellulose ethers show great potential in drug delivery systems. These complexes can encapsulate drugs and enable controlled release, making them suitable for sustained drug delivery. They offer advantages in terms of precise dosage and enhanced therapeutic efficacy. Coatings and adhesives also benefit from IPCs based on cellulose ethers. These complexes can form films with excellent mechanical strength and enhanced water resistance, providing durability and protection. They have applications in various industries where coatings and adhesives play a crucial role. In food packaging, IPCs based on cellulose ethers are highly relevant. These complexes can form films with effective barrier properties against oxygen and water vapor, making them ideal for packaging perishable foods. They help extend to shelf life of food products by minimizing moisture and oxygen transfer. Various methods, such as solvent casting, coacervation, and electrostatic complexation, are employed to synthesize IPCs based on cellulose ethers.

show abstract

Section: Introductionmentioning

confidence: 99%

Interpolymer Complexes Based on Cellulose Ethers: Application

Keldibekova,

Suleimenova,

Nurgozhina

et al. 2023

Polymers

View full text Add to dashboard Cite

show abstract

Phase separation of polyelectrolyte solutions

1957

View full text Add to dashboard Cite

It is shown theoretically that phase separation may arise in solutions of polyelectrolytes due to electrostatic interactions alone. Two models are considered thermodynamically. In both models the free energy is represented as the sum of an entropy of mixing term and an electrostatic free energy term, while the van der Waals attractions are neglected. In the one model, electrically charged rigid cylindrical rods are in solution with an equivalent amount of counterions but without additional electrolyte. The free electrical energy, in this case, is given by the expression of Lifson and Katchalsky. In the other model the solution contains two types of macroions of opposite charge. The macroions are flexible coils carrying a number of univalent charges, the charge density being sufficiently low. The electrical free energy in this case may be approximated by the Debye‐Hückel expression. For both models, it is shown that the decrease in the electrical free energy in a phase separation can, at given temperature and pressure, more than compensate for the increase in the entropy of mixing term. The effects of polymer concentration, dielectric constant, charge density, and salt content follow directly from the thermodynamic treatment of the models.

show abstract

Complex coacervation. I. General theoretical considerations

Voorn

1956

Recl. Trav. Chim. Pays‐Bas

View full text Add to dashboard Cite

Some characteristics of complex coacervation are briefly discussed. A general phase diagram is given, showing the influence of electrolytes on the composition of the two-phase system at constant charge density and mixing ratio of the two poly-electrolytes. The applicability of the phaserule is discussed.A model for calculations on complex coacervation is proposed, based on the interaction of oppositely charged coils in a sslt solution. I n t r o d u c t i o n .In homogeneous liquid systems, a demixing into two liquid, isotropic layers takes place under certain conditions. In most cases both layers are quite different in composition (e.g. in the system ether-water).A phase separation also occurs sometimes in solutions of colloids, for example in solutions of gelatin upon addition of alcohol or salts 1). The two phases in this case differ mainly in the concentration of gelatin.For this kind of phase separation, Bungenberg de Jong and Kruyt 1) introduced the name coacervation. The most conc. solution is called coacervate. The diluted phase is called equilibrium liquid.The above mentioned phase separation is considered by Bungenberg de Jong as caused by the dehydrating action of the added alcohol, leading to a reduction in solubility of the gelatin. The presence of charged groups plays little or no part in the phenomenon.On the other hand, if one mixes solutions of oppositely charged poly-electrolytes (e.9. gelatin and gum arabic between pH 1.7 and pH 4.7) coacervation is observed even without addition of alcohol.From these two examples we see, that coacervation may be sub. divided into two main groups: a. Simple coacervation (charged groups play no part) for phase separation). This classification is due to Bungenberg de Jong and K r u y t l ) . A discussion on this terminology has been given by Dervichian 2).Bungenberg de Jong 3 ) and his school carried out a great number of experiments on complex coacervation, especially on the system gelatin-gum arabic. He also suggested a theory for the mechanism of phase separation 4 ) . (See par. 2). Further experimental results on the same system have been given by Deroichian 5 ) and Bourgoin 6). A rather extensive list of literature on reactions between polymeric acids and bases has been given by Deuel 7 ) .Coacervation in non aqueous systems is of common occurrence and is extensively used in the fractionation of polymeric substances 8 ) .Calculations on phase equilibria in these systems have been given by Tompa 9 ) and Bamiord and Tompa 10).It is our purpose to give calculations on complex coacervation. Although it is exceptionally observed in systems containing only microions 11). we confine ourselves to the case of two (or more) polyelectrolytes in aqueous salt solution. Before going into detail, however, we have to mention in short some characteristics of complex coacervation and their qualitative explanation given by Bungenberg de S o m e a s p e c t s of c o m p l e x c o a c e r v a t i o n .To get complex coacervation, one mixes together two aqueous solutions of oppos...

show abstract

Zur Kenntnis der lyophilen Kolloide

Cited by 14 publications

References 9 publications

Interpolymer Complexes Based on Cellulose Ethers: Application

Interpolymer Complexes Based on Cellulose Ethers: Application

Phase separation of polyelectrolyte solutions

Complex coacervation. I. General theoretical considerations

Contact Info

Product

Resources

About