high purity fluorapatite (fa) with rod-like and spherical-like morphology was synthesized via sol-gel method. chemical characterization of fa powders was done by xrd and ftir analyses. crystallite samples were calculated using scherer method. morphology of fa powders was investigated with tem and sem images. the results revealed that increasing the time of hydrolysis of phosphate sols significa...

high purity fluorapatite (FA) with rod-like and spherical-like morphology was synthesized via sol-gel method. Chemical characterization of FA powders was done by XRD and FTIR analyses. Crystallite samples were calculated using Scherer method. Morphology of FA powders was investigated with TEM and SEM images. The results revealed that increasing the time of hydrolysis of phosphate sols significa...

in this paper, polyacrylamide/chromium acetate gel polymer system was prepared as water shut-off system to control water production in one of the iranian oil reservoirs condition. effect of various parameters such as temperature (90 °c) and water formation from view point of salinity and divalent cations, was evaluated on the gelation kinetic and gel strength using bottle testing method. the re...

In this paper, polyacrylamide/chromium acetate gel polymer system was prepared as water shut-off system to control water production in one of the Iranian oil reservoirs condition. Effect of various parameters such as temperature (90 °C) and water formation from view point of salinity and divalent cations, was evaluated on the gelation kinetic and gel strength using bottle testing method. Th...

The clinical effectiveness of tissue conditioners is influenced by their gelation characteristics and viscoelastic properties after gelation. The purpose of this study was to evaluate the effect of addition of ethyl alcohol (EtOH) on these properties, and to compare the effect of EtOH with that of the powder/liquid (P/L) ratio. Three tissue conditioners were used in this study. The gelation tim...

GELATION of hydrophilic colloids has frequently been studied in regard to its 'gelation time' (usually called the coagulation time) i.e. the time necessary for the gelatinising of a sol. The definition of 'gelation time,' however, is somewhat arbitrary and differs with the observer. Some observers consider a sol is gelatinised, when the vessel containing it can be inverted without spilling. Oth...

A two-site spatial coagulation model is considered. Particles of masses m and n at the same site form a new particle of mass m + n at rate mn . Independently, particles jump to the other site at a constant rate. The limit (for increasing particle numbers) of this model is expected to be non-deterministic after the gelation time, namely, one or two giant particles randomly jump between the two s...

The various molecular weight (MW) regenerated silk fibroins were prepared with different dissolution condition and the effect of MW on the gelation behavior of regenerated aqueous silk fibroin (SF) solution was investigated. The result of gelation time measurement indicated that the gelation of SF aqueous solution was accelerated by the increase of MW and SF concentration. When formic acid was ...

Among the methods available to reduce water production, injecting a gelling system composed of a polymer and a crosslinker has been widely used. In this work, a hydrogel was prepared by crosslinking of an aqueous solution containing hexamethylenetetramine (HMTA) as crosslinker, hydrochloric acid (HCl) as an activator, and the co-polymer of 2-acrylamido-2methyl-propanesulfonic-acid sodium salt (...

Kinetics as well as the evolution of the agarose gel topology is discussed, and the agarose gelation mechanism is identified. Aqueous high melting (HM) agarose solution (0.5% w/v) is used as the model system. It is found that the gelation process can be clearly divided into three stages: induction stage, gelation stage, and pseudoequilibrium stage. The induction stage of the gelation mechanism ...