With the use of viscometry, the cloud-point method, polarization microscopy, the turbidity-spectrum
method, and a polarization photoelectric apparatus, the relaxation pattern of the rheological behaviors,
phase transitions, and structures of the systems hydroxypropyl cellulose–ethanol and hydroxypropyl cellulose–
dimethyl sulfoxide are studied. The regions of existence of isotropic and anisotropic phases and the
concentration dependence of the sizes of supramolecular particles are determined. It is found that a magnetic
field increases the viscosities of solutions. The concentration dependences of viscosity and particle size are
described by curves with maxima.