Surfactant and nonionic

That is, nonionic surfactants caused an increase in the Stokes radius (R) of the particles due to penetration of the phospholipid surface layer and unfolding of apoprotein B molecules leading to particle assymetry at molar ratios of surfactant LDL2 of ca. 1000/1. At higher molar ratios, corresponding to 1-2 moles surfactant per mole of phospholipid, ionic surfactants and nonionics with HLB values < 14.6 caused rapid decreases in the Stokes radius due to breakdown of LDL2 into the lipid surfactant and protein surfactant micelles. 

Surfactants are divided into three main groups, based on their ionization in water these are anionic surfactants, cationic surfactants, and nonionic surfactants. If on ionization, one end of the molecule becomes a negative ion, the surfactant is known as an anionic surfactant as shown in Figure 2.3. 

Mixed solutions of cationic surfactants and nonionic poly(ethylene glycol) or block copolymers were employed for the synthesis of monolithic trimodal porous silica.[176] Lyotropic mixtures of block copolymers of different lengths with hydrophilic linear PEO chains were also applied to their nanocasting into bimodal micro-mesoporous silica to formulate the dependence of the mesopore sizes and the microporosity on the lengths or sizes of the hydrophobic and the hydrophilic blocks, but the mesostructures were worm-type in morphology and several hundred nanometers or more in size. 

Liquid cleaning compositions based on cationic surfactant, nonionic surfactant and nonionic polymer... 

Nonsubstantive photofilters, such as salicylic acid derivatives and octyl methoxycinnamate or benzophenone derivatives, have been included in leave-on formulations for skin and hair. Revlon possesses a patent describing the use of benzophenone and PABA derivatives with cationic surfactants and nonionic film formers in a mousse for hair protection [84], L Oreal has included camphorbenzalkonium sulfate as a proprietary photofilter in hair and skin care formulations [85-92],... 

A major disadvantage of microemulsions that contain cosurfactant is their instability on dilution with aqueous biological fluids, which generally occurs after in vivo administration through most routes of administration. Use of cosurfactants may also cause irritancy. Microemulsion systems devoid of cosurfactants could be prepared by using double alkyl chain surfactants and nonionic... 

Antonietti et al. described the preparation of mesoporous silica in systems containing mixtures of nonionic fluorinated surfactants and nonionic hydrocarbon block copolymer surfactants [60], The fluorinated surfactant was CF3(CF2)6-i6 C2H4(E0)4 5 and the hydrocarbon-based copolymer was poly(ethylene-co-bulylene)-block-poly(ethylene oxide). 

Due to the negatively charged zeolite surface at alkaline pH values, cationic surfactants are strongly adsorbed on to zeolite A (Figure 3.21). For mixtures of cationic and nonionic surfactants, a strong increase of the adsorbed amounts is observed in a certain concentration range (17). Because of hydrophobic interactions between the adsorbed cationic surfactants and nonionic surfactant molecules, additional nonionic surfactant molecules are probably adsorbed in a second layer from mixtures. These effects have an impact on the behaviour of zeolites in waste water. 

According to the electrical charge of their polar head, the three main classes of surfactants are anionic surfactants, cationic surfactants, and nonionic surfactants. A fourth class is added for the amphoteric and/or multifunctional surfactants [3],... 

Mixtnres of snrfactants and water-solnble polymers are of both fimdamental and practical interest. If one excludes hydrophobically modified polymers, whieh have hydrocarbon chains attached periodically to rather hydrophilie baekbones, polymer-surfactant complexes oecur only for (a) ionie surfactants and nonionic polymers and (b) ionic snrfactants and poly electrolytes having opposite eharges. In the former simation, for instance, mixtnres of SDS and PEO, the EO segments can penetrate the micelle snrfaee and separate the charged surfactant ions in much the same way as described above for ionic-nonionic smfactant mixtures. The EO segments also prevent water molecules from coming into direct contact with any... 

In the United States and Europe, the mildness concept is led by isethionate for a cleansing bar by Lever Brothers (Unilever Affiliate), followed by an amphoteric surfactant and nonionic alkylglycocide, which are really secondary surfactants to reduce the potential for irritation with a combination of typical anionics. The utilization of acylamino acid surfactants has just started in Western markets. In Europe, Biersdorf was the first company to use acylglutamate in a product for the mass market, although several upscale cosmetic cleansers pioneered its use on a small scale. 

When sterical effects dominate nonionic surfactant and nonionic... 

The amounts of the surfactants adsorbed [67] indicate that the formation of mixed bilayers between anionic (hydrocarbon or fluorocarbon) surfactants and nonionic (hydrocarbon or fluorocarbon) surfactants is more favorable than the formation of mixed bilayers between anionic fluorocarbon and anionic hydrocarbon surfactants on ferric hydrosols. 

Mixtures containing cationic fiuorinated surfactants and nonionic or cationic hydrocarbon surfactants have not been investigated extensively. 

The authors state that the anionic surfactants, cationic surfactants and nonionic surfactants in common use today are acceptable from the point of view of human toxicology. 

Probably the largest volume of published work in the field of surfactant-polymer interactions has involved surfactants and nonionic polymers such as polyvinylpyrrolidone (PVP), polyvinyl alcohol (PVA), polyvinyl acetate (PVAc), polypropylene glycol (PPG), methyl cellulose (MC), and polyethylene oxide (POE). The preferred surfactant has been (of course ) the classic—sodium dodecylsulfate (SDS). The results of most studies with SDS and similar surfactants indicate that the more hydrophobic the polymer, the greater is the interaction with anionic surfactants. For a given anionic surfactant, it has been found that adsorption progresses in the order PVP > PPG > PVAc > MC > PEG > PVA. In such systems, the primary driving force for surfactant-polymer interaction will be van der Waals forces and... 

The interactions between nonionic surfactants and nonionic polymers has been much less intensively studied than those for ionic surfactants. The limited number of reports available indicate that there is little evidence to indicate extensive direct surfactant-polymer association in such systems. Considering the size of the hydrophilic groups of most nonionic surfactants, their low erne s, and the absence of significant possibilities for head group-polymer interactions, the apparent absence of substantial interactions is not conceptually difficult to accept. An assertion that binding does not occur under any circumstance, however, would be foolish, given the complexities of polymer and surfactant science in general. 

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