Vesicular systems are a novel means of drug delivery that can enhance bioavailability of encapsulated drug and provide therapeutic activity in a controlled manner for a prolonged period of time.Liposomes were the firs...Vesicular systems are a novel means of drug delivery that can enhance bioavailability of encapsulated drug and provide therapeutic activity in a controlled manner for a prolonged period of time.Liposomes were the first such system but they suffer from a number of drawbacks including high cost and lack of stability at various pHs.Niosomes are a nonionic surfactant vesicular system,which can be easily and reliably made in the laboratory.Many factors affect noisome formation such as the method of manufacture,nature of surfactant and encapsulated drug,temperature at which the lipids are hydrated and the critical packing parameter.This review describes all aspects of niosomes including their different compositions,the various methods of preparation,the effect of changing manufacturing parameters,methods of characterization,factors that affect their stability,their use by various routes of administration,their therapeutic applications and the most important patents.The review also provides detailed information of the various types of niosomes that provide effective drug delivery.展开更多
Introducing the novel technique for enhancing oil recovery from available petroleum reservoirs is one of the important issues in future energy demands.Among of all operative factors,wettability may be the foremost par...Introducing the novel technique for enhancing oil recovery from available petroleum reservoirs is one of the important issues in future energy demands.Among of all operative factors,wettability may be the foremost parameter affecting residual oil saturation in all stage of oil recovery.Although wettability alteration is one of the methods which enhance oil recovery from the petroleum reservoir.Recently,the studies which focused on this subject were more than the past and many contributions have been made on this area.The main objective of the current study is experimentally investigation of the two nonionic surfactants effects on altering wettability of reservoir rocks.Purpose of this work is to change the wettability to preferentially the water-wet condition.Also reducing the residual oil saturation(Sor)is the other purpose of this work.The wettability alteration of reservoir rock is measured by two main quantitative methods namely contact angle and the USBM methods.Results of this study showed that surfactant flooding is more effective in oil-wet rocks to change their wettability and consequently reducing Sor to a low value.Cedar(Zizyphus Spina Christi)is low priced,absolutely natural,and abundantly accessible in the Middle East and Central Asia.Based on the results,this material can be used as a chemical surfactant in field for enhancing oil recovery.展开更多
In_2O_3 nanorods were prepared by sol-gel technique with nonionic surfactant controlling their morphology,and were characterized by TEM,TG-DSC and XRD.The results indicated that In_2O_3 nanorods had the length of abou...In_2O_3 nanorods were prepared by sol-gel technique with nonionic surfactant controlling their morphology,and were characterized by TEM,TG-DSC and XRD.The results indicated that In_2O_3 nanorods had the length of about 120 nm and diameter of 20 nm.The In_2O(OH)_4 dried gelatin was formed by partial dehydrating of In(OH)_3 molecules.The factors influencing the morphology of In_2O_3 nanorods and their growth mechanism were discussed.The geometry array parameter P of the nonionic surfactant was between 1/3～1/2 through calculation,which confirmed that the shape of the micelle was claviform.展开更多
The aim of this research is to study the effect of hydrophilic silica nanoparticles,sizes as CO_(2) foam stabilizer in the presence of nonionic TX100 surfactant.Two nanosilica sizes,15 and 70 nm,have been examined tho...The aim of this research is to study the effect of hydrophilic silica nanoparticles,sizes as CO_(2) foam stabilizer in the presence of nonionic TX100 surfactant.Two nanosilica sizes,15 and 70 nm,have been examined thoroughly.Physisorption of TX100 on silica nanoparticles(nanosilica)was characterized by adsorption isotherm and surface tension measurement,while CO_(2) foams stability was quantified based on their foamability,foam stability,particle partitioning in the foams,and bubble sizes.Results show that direct contact of TX100 with nanosilica does altered the wettability of hydrophilic nanosilica surface,enable them to lengthen CO_(2) foams life at certain surfactant and nanoparticles concentrations.For 15 nm nanosilica,CO_(2) foam stability shows excellent performance at 0.1 and 0.5 wt%TX100 concentrations.As for 70 nm nanosilica,CO_(2) foam demonstrates longer lifetime at much lower TX100 concentration,0.01 wt%.Without the presence of TX100,CO_(2) foams exhibit undesirable lifetime performances for both nanosilica sizes.Nanosilica partitioning in CO_(2) foams structures demonstrate consistent relation with contact angle measurement.Estimated bubble sizes shows insignificant effect on CO_(2) foams life.With the assists of nanosilica and TX100,enhanced oil recovery via CO_(2) foam injection succeeds in increasing oil production by 13e22%of original oil-in-place(OOIP).展开更多
文摘Vesicular systems are a novel means of drug delivery that can enhance bioavailability of encapsulated drug and provide therapeutic activity in a controlled manner for a prolonged period of time.Liposomes were the first such system but they suffer from a number of drawbacks including high cost and lack of stability at various pHs.Niosomes are a nonionic surfactant vesicular system,which can be easily and reliably made in the laboratory.Many factors affect noisome formation such as the method of manufacture,nature of surfactant and encapsulated drug,temperature at which the lipids are hydrated and the critical packing parameter.This review describes all aspects of niosomes including their different compositions,the various methods of preparation,the effect of changing manufacturing parameters,methods of characterization,factors that affect their stability,their use by various routes of administration,their therapeutic applications and the most important patents.The review also provides detailed information of the various types of niosomes that provide effective drug delivery.
文摘Introducing the novel technique for enhancing oil recovery from available petroleum reservoirs is one of the important issues in future energy demands.Among of all operative factors,wettability may be the foremost parameter affecting residual oil saturation in all stage of oil recovery.Although wettability alteration is one of the methods which enhance oil recovery from the petroleum reservoir.Recently,the studies which focused on this subject were more than the past and many contributions have been made on this area.The main objective of the current study is experimentally investigation of the two nonionic surfactants effects on altering wettability of reservoir rocks.Purpose of this work is to change the wettability to preferentially the water-wet condition.Also reducing the residual oil saturation(Sor)is the other purpose of this work.The wettability alteration of reservoir rock is measured by two main quantitative methods namely contact angle and the USBM methods.Results of this study showed that surfactant flooding is more effective in oil-wet rocks to change their wettability and consequently reducing Sor to a low value.Cedar(Zizyphus Spina Christi)is low priced,absolutely natural,and abundantly accessible in the Middle East and Central Asia.Based on the results,this material can be used as a chemical surfactant in field for enhancing oil recovery.
文摘In_2O_3 nanorods were prepared by sol-gel technique with nonionic surfactant controlling their morphology,and were characterized by TEM,TG-DSC and XRD.The results indicated that In_2O_3 nanorods had the length of about 120 nm and diameter of 20 nm.The In_2O(OH)_4 dried gelatin was formed by partial dehydrating of In(OH)_3 molecules.The factors influencing the morphology of In_2O_3 nanorods and their growth mechanism were discussed.The geometry array parameter P of the nonionic surfactant was between 1/3～1/2 through calculation,which confirmed that the shape of the micelle was claviform.
文摘The aim of this research is to study the effect of hydrophilic silica nanoparticles,sizes as CO_(2) foam stabilizer in the presence of nonionic TX100 surfactant.Two nanosilica sizes,15 and 70 nm,have been examined thoroughly.Physisorption of TX100 on silica nanoparticles(nanosilica)was characterized by adsorption isotherm and surface tension measurement,while CO_(2) foams stability was quantified based on their foamability,foam stability,particle partitioning in the foams,and bubble sizes.Results show that direct contact of TX100 with nanosilica does altered the wettability of hydrophilic nanosilica surface,enable them to lengthen CO_(2) foams life at certain surfactant and nanoparticles concentrations.For 15 nm nanosilica,CO_(2) foam stability shows excellent performance at 0.1 and 0.5 wt%TX100 concentrations.As for 70 nm nanosilica,CO_(2) foam demonstrates longer lifetime at much lower TX100 concentration,0.01 wt%.Without the presence of TX100,CO_(2) foams exhibit undesirable lifetime performances for both nanosilica sizes.Nanosilica partitioning in CO_(2) foams structures demonstrate consistent relation with contact angle measurement.Estimated bubble sizes shows insignificant effect on CO_(2) foams life.With the assists of nanosilica and TX100,enhanced oil recovery via CO_(2) foam injection succeeds in increasing oil production by 13e22%of original oil-in-place(OOIP).
