Gel-like state

The liquid-ordered gel-like state of liposomes is stabilized by S-layer coating [123]... 

UHMWPE gels have been studied mainly for their processability into high modulus/strength products. The viscoelastic behavior of this polymer/solvent system, as well as others which are capable of forming a gel-like state at some suitable concentration, has received little attention. Previous studies have been carried out by Ferry et al. (6,7) with gel systems of cellulose derivatives and polyvinychloride... 

S.P. Papkov. Gel-like State of Polymers. Moscow, Khimiya, 1974. 

The hose is extruded from the polymer and plasticizer mixture (Fig. 2.5c). Liquid Cl are fed to the extruder mandrel, where the hose serves as a cavity for the inhibiting liquid using a special device. Upon cooling the hose is transferred into a gel-like state in which Cl together with PI are encapsulated into... 

Papkov SP (1974) Gel-like state of polymers. Khimiya, Moscow, in Russian... 

In a major part of the used concentrations, the system is in gel-like state since small Ys values are observed. The gel is decomposed with decreasing content of gelatin that appears as an increase in the WBW amounts and the Ys value. However, the complete decomposition of the gel at low gelatin content does not occur and the Ys value remains smaller the maximal value (202 J/g) observed at Cy=3 wt% and Co=0 (Table 7.5). 

Egelhaaf, W.C.K. Poon, personal communication). The appearance of the particle gel can be explained as follows. When the attraction becomes sufficiently strong the particles stick irreversibly and form a space-spanning network. In such cases the phase separation process will not reach its equilibrium state but rather a nonequilibrium gel-like state is encountered. This has been well-studied for small q (see Sect. 4.5.2) but its appearance for q > 0.3 has not received much attention yet. 

Barrett and Thomas (1) have made an extensive study of nucleation and particle growth in dispersion polymerisationo They conclude that for poly (methyl methacrylate) in aliphatic hydrocarbon the threshold degree of polymerisation is sufficiently low so that nearly all oligomers form nuclei or are captured by particles before their radicals are terminated. In consequence nearly all polymerisation takes place within the particles, the concentration of polymer in the diluent phase remains extremely low and nearly all radicals pass into the particles. Polymerisation proceeds in the swollen particles and is greatly accelerated because of the reduction in the diffusion controlled termination rate, due to the high viscosity or gel-like state of the particle. It is usual to add an... 

Coagulation n (1) A physical or chemical action inducing transition from a fluid to a semi-solid or gel-like state, or the bringing together of small, individual particles into clumps. (2) Process whereby a fluid liquid is changed into a thickened, curdled or congealed mass. 

Typically if a material is stretched in one axis, it will contract in the perpendicular directions, with the ratio of perpendicular contraction to extension being described by Poisson s ratio. It is expected to be between 0.3 and 0.4, but can be -0.5 (constant volume condition) when the polymer is in a gel-like state. The response to stress in three axes on the strain in one axis (e.g., x) in an isotropic material at small strain is given by... 

The functions of liposomes, such as interaction, incorporation, recognition, and stabilization, are attributed to the microfluidity of a membrane and its ttansitional state [2], Lipids dispersed in water can form a variety of structures, for example, the liposome-type structure at low lipid/water ratios. As temperature increases, the lipid phase shifts from a crystalline to a condensed gel-like state and then to a fluidic, expanded state, and such a transition state at the corresponding temperature can be determined by various methods [2,16]. 

---