Factors affecting cmc of surfactants pdf
Factors affecting cmc of surfactants pdf
The cmc values of dissymmetric surfactants designated as m–6–6 are about one order of magnitude higher than those of the corresponding m–6–m symmetric surfactants and the cmc decreases as the m/n ratio increases.
Abstract: The laboratory experiments described in this work present the CMC-determination of some surfactants by following three different methods, which require the use of the very common techniques in physical chemistry laboratories, such as UV-Vis spectroscopy,
The critical micelle concentration (CMC) values and the surface tension at CMC of PGML and C 12 EO n increased linearly with an increase in the number of glycerol and oxyethylene units, respectively; the slope of the increase was greater for PGML than C 12 EO n.
Factors affecting CMC and micelle size 1) Effect of hydrophobic group. -if hydrophobic group is aromatic, micelle does not formed. -length of hydrocarbon chain is directly proportional to micelle size & inversely proportional to CMC. We express this in mathematical term, Log [CMC] = A – Bm where, A & B are homologous series constant. m is the no. of carbon atom in chain.
FACTORS AFFECTING THE CMC OF NONIONIC SURFACTANTS 124 A. Alkyl Chain Length 124 B. Temperature 133 C. Connecting Group in Structure 139 D. Pressure 144 E. Salts and Solvents 150 V. MIXED-SURFACTANT SYSTEMS 157 A. Mixtures of Homogeneous Nonionic Surfactants 158 B. Mixtures of Anionic and Nonionic Surfactants 159 C. Mixtures of Cationic and Nonionic Surfactants …
Critical micelle concentration (CMC) is defined as the concentration of surfactants in which micelles are spontaneously formed. Below the CMC point surfactant molecules tend to accumulate at the interface, reducing surface tension. At CMC, the surface tension of the solution does not change but remains constant, as the gas-liquid interface is already saturated with the surfactant molecules
01Surfactant concentration CMC Factors affecting the cmc: molecular structure of the surface active agent. Factors affecting the cmc: effect of additives. HLB of surfactants • HLB ca. 1 to 3: Antifoams / inverse micelles • HLB ca. 3 to 8: Water-in-Oil Emulsifiers • HLB ca. 7 to 9: Wetting and spreading agents • HLB ca. 8 to 16: Oil-in-Water Emulsifiers • HLB ca. 13 to 16
In this study, non-ionic surfactants, polyoxyethylene sorbitan fatty acid esters (polysorbate) are chosen to examine the temperature effect on the CMC over a wide temperature range. The enthalpy and entropy of micelle formation are evaluated according to the phase separation model. The surface tension of solutions was determined by means of Du
CHEMISTRY PAPER No.10 : TITLE: Physical Chemistry MODULE No.28 : TITLE: Factors affecting CMC of Micelle Table 2 List of CMC values for non-ionic surfactants
National Institute of Technology Rourkela CERTIFICATE This is to certify that the thesis entitled, “EFFECT OF SURFACTANT ON EVAPORATION OF WATER” submitted by Shri Rupam Ranjan Biswal in partial fulfillments for the
The critical micelle concentration CMC is the surfactant concentration at and above which micelles are formed. It can be determined for surfactant solutions by measuring the surface tension at …
compared to nonionic surfactants Ionic surfactants cmc= 10-3 –10-2 M Nonionic surfactants cmc= 10-4 –10-3 M. Solubility of surfactants-The Krafft temperature • Solubility of surfactants highly T dependent • Solubility is usually low at low T, rising rapidly in narrow range • No micelles possible above a certain temperature • The point where solubility curve meets CMC curve is the
Removal of PAHs with surfactant-enhanced soil washing
and Ionic-Nonionic Surfactants in Aqueous Media Mixed
surfactant is compared with the surfactants of known HLB values. The HLB scale can be constructed by assigning a value of 1 to oleic acid and a value of 20 to sodium oleate; intermediate values are derived by mixing oleic acid and oleate in
PDF The surface tension (ST) of 30 mg L solutions of estuarine, lacustrine and Aldrich humic acids (HA) was monitored under varied conditions of pH (2 to 12), ionic strength (up to 0.3 with NaCl
surfactant concentration must be above the CMC. The SlO-7 dialyzed almost as rapidly as cholate and The SlO-7 dialyzed almost as rapidly as cholate and far more rapidly than Brij 58 and Triton X-100.
Above a certain surfactant concentration, termed the critical micelle concentration (CMC), surfactants tend to form colloidal-sized association structures, or micelles. Within these structures, the hydrophilic heads are directed outwards towards the solvent with the hydrophobic tails of the surfactants associate and are pointed towards the center or interior of the micelle [ 65 ].
2. Aggregation and adsorption at interfaces Surfactants, literally, are active at a surface and that includes any of the liquid/liquid, liquid/gas or liquid/solid systems, so that the subject is quite
Among all identified factors affecting γ CMC of sugar-based surfactants (polar head size, alkyl chain length and branching), polar head size was found to exhibit the …
Abstract: An important part of the wound healing process is the removal of necrotic tissue from a wound to promote healing. Enzymatic debridement is one of the widely used methods to accomplish this goal.
conventional surfactants, which may be the reason for more lowering of surface tension at CMC by geminis. The higher surface activity means that lower [surfactant]
Concept of MIcelle & CMC 1. Presented by Akshay A. Pawar M. Pharm 1st Sem Department of Pharmaceutics R. C. Patel Institute of Pharmaceutical Education & Research, Shirpur 1 2. 2 CONTENT Introduction Surfactant Concept of Micelle Micelle formation Critical micelle concentration (CMC) Determination of the CMC Factors affecting CMC Micelle Solubilization Conclusion 3. Introduction In …
To estimate the CMC of the cationic and anionic surfactants two plots of conductivity as a function of the concentration of DPC and SDS in aqueous solutions at different temperatures were made.
Langmuir 1997, 13, 6683-6688 6683 Theoretical Model and Phase Behavior for Binary Surfactant Mixtures I ~ Lei Huang and P. Somasundaran* Langmuir Center for Colloids and Interfaces, Columbia University,
In order to elucidate the mechanisms involved in the sorption of the surfactants on the clay, their sorption was also performed at added concentrations of the surfactant below the cmc for the same clay concentration (1.6 g L −1); the amount of surfactant in solution was determined by …
Anik Yusuf TextileTuts Soap ManufacturingMicelle FormationFactors Affecting CMC CMC: The concentration above which micelle formation becomes appreciable is termed as the Critical micelle concentration (C.M.C.). At low surfactant concentration the surfactant molecules arrange on the surface. When more surfactant is added the surface tension of the solution starts to rapidly decrease …
Factors affecting the development of RDS Figure 1. Incidence of RDS and surfactant requirement at RPA Newborn Care, 1992-1998 . Evidence for Surfactant in Preterm Infants The following summarises the evidence for exogenous surfactant in preterm infants. Natural versus synthetic surfactant Both natural and synthetic surfactants are effective in the treatment and prevention of RDS. They reduce
Surfactants International Union of Pure and Applied
The cmc values obtained using the turbidity method were compared with cmc values obtained by the surface tension method and with data given in the literature. Values obtained by our simple method have comparable accuracy with data obtained from more elaborate experiments.
The effectiveness of a surfactant in enhancing the removal of a contaminant from the subsurface can be expected to be a function not only of the surfactant’s interaction with the contaminants, but
8/03/2008 · CMC values of surfactants in water were taken as reference from literature, as SDS , ASC-8 and SLES . All the surfactants were investigated using increasing concentrations, i.e. from CMC …
is called critical micelle concentration. A graph of surface tension Figure 2. Surface tension against the surfactant concentration (logaritmic scale). 2 ATTENSION TN 3 1) At very low surfactant concentration only slight change in surface tension is detected. 2) Addition of surfactant decreases the surface tension drasti-cally 3) At CMC point, surface becomes saturated and the addition of
Factors Affecting Surfactant Mikko Hallman’, T. Allen Merritt2s3, Anneli Responsiveness Kari4 and Kristina By1 There is a wide variability in the therapeutic responsiveness to exogenous surfactant, a drug that has become generally available for the treatment of lung immaturity and respiratory distress syndrome. Recent studies have demonstrated evidence that thera- pies decreasing lung edema
The excess free energy of micellization at the first CMC and the second CMC as a function of the surfactant mixture composition. Curves are eye guides Both figures show that the interaction is different in the NaOL-rich system than in the CTAB-rich one.
Critical Micelle Concentration and HLB of the Sodium
Factors Affecting the Critical Micelle Concentration (CMC) Factors Affecting Head-to-Head Repulsion Factors Affecting Chain/Chain Attraction • Head Group Charge
process can affect particle size. For exam- ple, the effect of monomer type is com- plex and often sensitive to other ingredi- ents and the polymerization procedure. However, the quantity and nature of the surfactants are major factors. In general, a surfactant molecule con- tains both polar (hydrophilic) and non- Surfactant examples: Anionic surfactant sodium Nonionic surfactant resulting
PDF Version. Abstract. In this work, we provide a review of micellar solubilization of drugs in surfactant systems, blending it with basic information on surfactants structure and properties, as well as the applications for drug delivery. Surfactants and Micelles. Surfactants are amphiphilic molecules composed of a hydrophilic or polar moiety known as head and a hydrophobic or nonpolar
Micellar solubilization of drugs. Page Not Found
Soap Manufacturing|Micelle Formation|Factors Affecting CMC
cmc of nonionic surfactants calculated from implicit-solvent simulations monotonically increases with temperature, 39 unless there is a temperature dependent parameter. 20,42 For
Factors affecting the choice of aquatic surfactants Kim Patten WSU Long Beach *Caveats*
concerned with the study of various factors affecting this equilibrium. The most common way of investigating the thermodynamics of micellar systems is to determine the changes in the CMC with temperature or in the presence of various additives or cosolvents.
One classic method to determine CMC is to measure the surface tension of the solutions (at several surfactant concentrations) with a tensiometer.
Plot graphs of Λ versus c 1/2 (CMC 1), or γ versus c, and γ versus ln c (CMC 2). Determine a value for the c.m.c. (i.e. the concentration at which a discontinuity occurs) in each case and compare values.
Surfactant Parameter Effect on Cleaning Efficiency
The Influence of Metal Salts Surfactants and Wound Care
Article (PDF Available) CMC values for surfactants [23, 24]. In general, almost. linear dependencies of HLB on log CMC are obtained, with . the form [11, 12]: Log CMC ¼ a þ b: HLB ð 2 Þ
Hydrophile-Lipophile Balance and Critical Micelle Concentration as Key Factors Influencing Surfactant Disruption of Mitochondrial Membranes* (Received for publication, January 26, 1976) ROBERT W. EGAN$ From The Merck Institute for Therapeutic Research, Rahway, New Jersey 07065 MARJORIE A. JONES AND ALBERT L. LEHNINGER From the Department of Physiological Chemistry, The Johns …
surfactants, Cbulk, and the surface concentration, Γ, both increase with C until C reaches cmc. After C After C reaches cmc, all added ‘excess’ surfactants form micelles so that the bulk concentration of the
3. Surfacemodification (mainly) using surfactants Monika Österberg Spring 2017 CHEM-E2150 Interfacial Phenomena in Biobased Systems Outline Recap on the self-assembly of amphiphiles into micelles and factors affecting the cmc Examples on applications of surfactants Surface modification methods – how to alter the chemistry or morphology of a (solid) surface. 1/19/2017 2 Effect of of …
This law is valid for the C8~C16 members. the CMC of ionic surfactant is larger than non-ionic.Factors affecting critical micelle concentrations • Structure of the surfactant When the hydrophobe is same.Bm where m is the number of carbon atoms in the chain and A and B are constants for a homologous series . Above the C18 member the CMC tends to be approximately constant. The CMC is
organic compounds that can affect the observed cmc value. Oil-soluble dyes readily soluble in micellar solutions ( 4 ), or changes produced by surfactants in the UV–visible spectrum
Surfactant selection is key to many emulsion polymer
Factors Affecting Critical Micelle Concentration II (a). Surfactant Structure : Presence of electrolyte in the aqueous solution affect CMC of surfactants .Effect is greater in case of cationic and anionic surfactant in comparison to amphoteric surfactants, which further has more effect than non-ionic surfactants [10, 11]. III. Materials And Methods All the chemicals such as CTAB, NaCl, CKC
the nature of interactions and factors affecting them in aqueous media so as to understand how these control the product performance. The tendency of different surfac-tants to form mixed micelles is governed by their attractive (synergistic) or repulsive (antagonistic) interactions and is often explained from the β parameter estimated using Rubingh’s regular solution theory (6). Extensive
upon various factors. Micelles are spontaneously formed ddition of and a more surfactant leads to formation of more micelles increasing the micellar concentration or the micellar growth while the surfactant monomers in the system remain more or less unchanged. The result is a decrease in the average distance between the micelles and hence an increase in inter-micellar repulsion. In order to
General Factors Affecting Surfactant Self-Assembly and cmc. The fundamental physical chemistry which underpins the behaviour of surfactants and (micro)emulsions has been extensively covered e.g.3-5 .
interest has been to identify the basic properties of nonionic surfactants that may affect cleaning processes. In (CMC) of a surfactant is the concentration at which micelles begin to form. At this point, several properties of the solution change abruptly, including surface tension and solubilization. The surface tension decreases with increasing
Dow surfactants include some of the most familiar anionic and nonionic products in the industry, known worldwide for excellent emulsification and dispersion.
Effect of temperature With non ionic surfactants.FACTORS AFFECTING CMC 5. At temperatures up to the cloud point there is an increase in micellar size and a corresponding decrease in CMC. Aqueous solutions of many non-ionic surfactants become turbid at a …
Precipitation and Critical Micelle Concentration (CMC) of three sulfated-based anionic extended surfactants and one pyridinium-based cationic surfactant mixtures to improve efficiency of surfactant-based groundwater remediation. Cetylpyridinium Chloride was used as cationic surfactant and Alkyl propoxylated sulfate surfactant with difference in number of propylene oxide(PO) group (4 and 8
In colloidal and surface chemistry, the critical micelle concentration (CMC) is defined as the concentration of surfactants above which micelles form and all additional surfactants added to the system go to micelles.
its CMC, and the studies and industrial applications of a 2 surfactant are always based on the value of its CMC. Also, micelle formation enables emulsification, solubili-
10/01/2014 · Read Online >> Read Online An ionic surfactants pdf files. factors affecting critical micelle concentration pdf. solubilisation by the use of surfactants. factors affecting cmc of surfactants. surfactant chemistry pdf. surfactants and their applications ppt. surfactants and their applications . application of surfactants in pharmacy. surfactant types and uses. 18 Feb 2013 …
FACTORS AFFECTING SURFACTANT RESPONSIVENESS Influence of mode of administration and ventilation, disease stage and type of surfactant FAKTOREN DIE DE WERKING V AN SURFACTANT …
Some surfactants (e.Krafft point.g.based surfactants) dehydrate and phase separate upon temperature elevation (“cloud point”). Factors affecting the cmc: molecular structure of the surface active agent .
(1) Above the CMC, any additional surfactant molecule is incorporated into the micelles, and the concentration of the free molecules, i.e., the non-associated surfactant, remains constant.
Factors Affecting Site Remediation of diesel contaminated soils using surfactants A.K.DARBAN*, H. GANJIDUST, and E. SALEHIAN Faculty of Engineering,Tarbiat Modares University,Modares Environmental Research
In colloidal and surface chemistry, thecritical micelle concentration (CMC) is defined as the concentration of surfactants above which micelles form and all additional surfactants added to the system go to micelles. The CMC is an important characteristic of a surfactant.
The critical micellar concentration (CMC) of these two surfactants was determined as 156 and 59 mg L 1 using the meth- od of Du Nouy tensiometer (Harkmgs, 1959), respectively.
FACTORS AFFECTING DISSOLUTION RATE Divided into five classes- a. Physicochemical Properties of Drug b. Drug Product Formulation Factors c. Processing Factors
Surfactant properties of purified polyglycerol
Investigating the impact of sugar-based surfactants
A Simplified Method for the Determination W of Critical
Theoretical Model and Phase Behavior for Binary Surfactant
Hydrophile-Lipophile Balance and Critical Micelle