Liquid paraffin

About: Liquid paraffin is a research topic. Over the lifetime, 6185 publications have been published within this topic receiving 52956 citations.

The influence of fatty alcohols on the structure and stability of creams prepared with polyethylene glycol 1000 monostearate/fatty alcohols.

Abstract: Synopsis Liquid paraffin in water emulsions stabilized by PEG 1000 monostearate and alcohols cetostearyl (c/s) myristyl (C(14)), cetyl (C(16)) or stearyl (C(18)) and ternary systems prepared by dispersing each fatty alcohol and surfactant in water were examined during 30 days using a Ferranti-Shirley cone and plate viscometer. Microscopical diffusion experiments investigated interaction between PEG 1000 monostearate solution and each alcohol at high and low temperature. The rheological properties of each ternary system and corresponding emulsion were similar. Formulations prepared from pure C(14), C(16) or c/s alcohols were semisolid immediately after preparation. Flow curves were in the form of anticlockwise hysteresis loops with spur points. On ageing for 24 h, structure built-up over a time scale similar to that observed in diffusion experiments, so that apparent viscosities increased. However, on further ageing the pure C(14) and C(16) alcohol systems were not as stable as those prepared with c/s alcohol. In contrast, the pure C(18) systems were mobile liquids and the emulsion cracked within days. This correlated with diffusion experiments where little interaction was observed between stearyl alcohol and PEG 1000 monostearate.

Ecofriendly demulsification of water in oil emulsions by an efficient biodemulsifier producing bacterium isolated from oil contaminated environment.

Abstract: Water in oil emulsions increase oil processing costs and cause damage to refinery equipment which necessitates demulsification. Since chemical demulsifiers cause environmental pollution, biodemulsifiers have been paid more attention. This study aims to identify biodemulsifier-producing bacteria from petroleum contaminated environments. As a result, several biodemulsifier producing strains were found that Stenotrophomonas sp. strain HS7 (accession number: MF445088) which produced a cell associated biodemulsifier showed the highest demulsifying ratio, 98.57% for water in kerosene and 66.28% for water in crude oil emulsion after 48 h. 35 °C, pH 7, 48 h incubation and ammonium nitrate as nitrogen source were optimum conditions for biodemulsifier production. Furthermore, it was found that hydrophobic carbon sources like as liquid paraffin is not preferred as the sole carbon source while a combination of various carbon sources including liquid paraffin will increase demulsification efficiency of the biodemulsifier. The appropriate potential of this biodemulsifier strengthens the possibility of its application in industries especially petroleum industry.

Short-term effect of microencapsulated hydrocarbons on shell growth of Mytilus edulis

Abstract: Two North Sea crude oils, weathered crude oil, n-alkanes, medical liquid paraffin and a fish oil were microencapsulated and added to seawater. This gave a medium containing both water soluble fractions (WSF) and oil particles, and thus simulated the conditions in natural seawater contaminated with oil. The microencapsulated oils were fed to Mytilus edulis L. in different concentrations, and the growth in terms of shell length of the mussels was measured in intervals of 24 to 48 h for 4 to 12d. With the crude oilss A and B, weathered crude oil and n-alkanes at concentrations≧1 mg l-1, shell growth rate decreased rapidly compared to controls. With liquid paraffin at levels of 1 to 12 mg l-1, a small but significant negative effect on shell growth occurred after 5 d of exposure. Exposure to fish oil at 1 and 4 mg l-1 gave no significant reduction in growth rate. The toxicity of the different hydrocarbons was not related to their content of aromatic fractions. Crude oil B was tested at concentrations ranging from 0.12 to 12 mg l-1. At 0.12 mg l-1 shell growth was not significantly different from the control, while at 0.25 and 0.50 mg l-1 a temporary and significant stimulation of growth was observed. The product concentration (C)xresponse (R) shows a linear regression on exposure time (t). The regression model CxR=75-0.18t is used to estimate EC-values (effect of a given concentration) for given response levels. The model gives a very good fit to observed data.

Rheology of systems containing cetrimide-cetostearyl alcohol: variation with temperature.

Abstract: The viscoelastic gel in the continuous phase of a liquid paraffin in water emulsion (stabilized by the mixed emulsifier cetrimide-cetostearyl alcohol) is similar to that formed by dispersing cetrimide and cetostearyl alcohol in water. The effect of temperature changes on the rheological properties of the emulsion and ternary system have been examined in continuous shear and in creep, and variations in the viscosities and compliances have been correlated with thermal phase transitions determined microscopically. The emulsion and ternary system were of maximum consistency at approximately 38° and 43° respectively; these temperatures respresent the transition from frozen smectic to liquid crystalline phase. At higher temperatures, the compliances rose and the viscosities fell as the network weakened and finally dissolved to form an isotropic solution.

Novel Carbon Nanoparticles Derived from Biodiesel Soot as Lubricant Additives

Abstract: The objective of this study was to investigate the roles and tribological mechanisms of onion-like carbon nanoparticles derived from biodiesel soot (BDS) when applied in water (H2O) and liquid paraffin (LP). In this study, we prepared nitric acid-treated BDS (NA-BDS) as an additive to H2O and NA-BDS modified with oleylamine (NA-BDS-OLA) as an additive to LP. Raman spectroscopy, field-emission transmission electron microscopy, Fourier transform infrared spectroscopy, and zeta potentiometry were used to characterize the results of the nitric acid treatment and oleylamine modification. The tribological behaviors and corresponding mechanisms of the new onion-like carbon nanoparticles were evaluated using a ball-on-disc reciprocating tribometer, as well as field-emission scanning electron microscopy, three-dimensional laser scanning microscopy, and Raman spectroscopy. The results indicated that the additives NA-BDS and NA-BDS-OLA, which were onion-like carbon nanoparticles with sizes ranging from 35 to 40 nm, enhanced the antiwear and friction reduction properties of H2O and LP, respectively. Through tribo-mechanisms, these types of soot can serve as spacers and ball bearings between the rubbing surfaces. Moreover, exfoliation under a high load as a result of the formation of a graphitic layer facilitates easy shearing.