Effect of chain length and

S. K. Kumar, M. Vacatello, D. Y. Yoon. Off-lattice Monte Carlo simulations of polymer melts confined between two plates. 2. Effects of chain length and plate separation. Macromolecules 25 2189-2197, 1990. 

Effects of chain length and substitution. Comparing the stabiiity of alkyl nitrates or aliphatic nitrated derivatives, in spite of instability to the extent of making it hazardous to handle them, stability increases rapidly with the number of alkyl groups. So nitroethanes, especially nitropropanes and nitrobutanes, are commonly used industrial raw materials. 

Influence of subphase temperature, pH, and molecular structure of the lipids on their phase behavior can easily be studied by means of this method. The effect of chain length and structure of polymerizable and natural lecithins is illustrated in Figure 5. At 30°C distearoyllecithin is still fully in the condensed state (33), whereas butadiene lecithin (4), which carries the same numEer of C-atoms per alkyl chain, is already completely in the expanded state (34). Although diacetylene lecithin (6) bears 26 C-atoms per chain, it forms both an expanded and a condensed phase at 30°C. The reason for these marked differences is the disturbance of the packing of the hydrophobic side chains by the double and triple bonds of the polymerizable lipids. At 2°C, however, all three lecithins are in the condensed state. Chapman (27) reports about the surface pressure area isotherms of two homologs of (6) containing 23 and 25 C-atoms per chain. These compounds exhibit expanded phases even at subphase temperatures as low as 7°C. 

Cyclic olefins and diolefins form much more aerosol than 1-alkenes that have the same number of carbon atoms (for example, cyclohexene 1-hexene, and 1,7-octadiene 1-octene). The same effect of chain length and double-bond position is observed for diolefins (1,7-octadiene > 1,6-heptadiene > 1,5-hexadiene, and 1,7-octadiene 2,6-octadiene). Heavier unsaturated cyclic compounds, such as indene and terpenes, form even more aerosol. 

Figure 3. Effect of chain length and saturation on relative burning velocities of straight-chain (or nonsubstituted ring) hydrocarbons at 25° C. and 1 atmosphere (30, 32, 48)...

ALIPHATIC OLEFINS. The effects of chain length and chain branching described for paraffins apply for olefins. 

V. Molinier, P. J. J. Kouwer, J. Fitremann, A. Bouchu, G. Mackenzie, Y. Queneau, and J. W. Goodby, Self-organizing properties of monosubstituted sucrose fatty acid esters The effects of chain length and unsaturation, Chem. Eur. J., 12 (2006) 3547-3557. 

Cho, D.W., Choi, J.H., Oh, S.W., Quan, C., Yoon, U.C., Wang, R., Yang, S., and Mariano, P.S. (2008) Single electron transfer-promoted photocydization reactions of linked acceptor-polydonor systems effects of chain length and type on the effidencies of macrocydic ringforming photoreactions of tethered a-silyl... 

Liu,FY.,Kildsig,D. O., and Mitra,A. K. (1992),Complexation of 6-acyl-O-P-cyclodextrin derivatives with steroids, effects of chain length and substitution degree, Drug Del. Ind. Pharm., 18,1599-1612. 

An overall comparison of the results of tests using brine indicates that ethoxylated alcohols and ethoxylated alcohol sulfates were superior for mobility control in enhanced oil recovery. It was found that the optimum hydrophobe for ethoxylated alcohol is a mixture with an average chain length of about 13 carbon atoms. The degree of ethoxylation is also important. It was found that 6 ethoxy late groups is close to the optimum. The formation of the sulfate ester tended to lessen the effect of chain length and reduce the optimum number of ethoxylate groups to 5. 

Blok, M. C. et al. The effect of chain length and lipid phase transitions on the selective permeability properties of liposomes. Biochimica et Biophysica Acta 406 187-196, 1975. 

TABLE 3. Melting Points of Some Fatty Acids and Methyl Esters Illustrating the Effect of Chain Length and Unsaturation. 

Hecht, S. Vladimirov, N. Erechet, J.M. Encapsulation of functional moieties within branched star polymers effect of chain length and solvent on site isolation. J. Am. Chem. Soc. 2001,123, 18-25. 

SET induced cyclisations have been carried out on a series of non-conjugated dienes one component of which is a silyl ether. Irradiation in acetonitrile of dienes such as (330, R = H) using DCA as the electron accepting sensitiser results in the formation of the radical-cation of the diene which on cyclisation affords the cyclic ketone (331) in 25% yield. The reaction is solvent sensitive and in a mixture of acetonitrile/propan-2-ol yields three products which are identified as (331, 30%) and two minor products (332, 11%) and (333, 9%). The reaction is suggested to have some considerable synthetic potential and the effect of chain length and substituents on the reaction has been evaluated. Thus (334) is converted into (335, 11%) while (330, R = Me) affords an isomeric mixture of products (336). Other studies with silyl ether derivatives have examined the electron transfer-induced ring opening processes encountered with the cyclopropane derivatives (337). ... 

Wang, J. et al.. Effects of chain length and structure of cationic surfactants on the adsorption onto Na-kaolinite, J. Colloid Interf. Sci., 213, 596, 1999. 

Rawicz W. Olbrich KC, McIntosh T, Needham D, Evans E. Effect of chain length and unsaturation on elasticity of lipid bilayers. Biophys J 2000 79 328-339. 

The process involves cyclization within the radical cation 23. Several other examples of this type of cyclization have been reported, again using the same reaction conditions. This has helped to demonstrate the scope of the process. Thns the parent system 24, R = H, affords the cyclic ketone 25 in 25% yield. The effect of chain length and substituents on the reaction has also been evaluated. Thus 24, R = Me, is converted into the mixture of isomers 26 while 27 affords 28. Tricyclic products such as 29 can also be obtained in moderate yields from the cyclization of 30. The basic reaction of 24 is solvent-sensitive. This is demonstrated by the formation of three products when the reaction is carried out in acetonitrile/propan-2-ol. These were identified as the original product (25, 30%) and two minor products 31 formed in 11% and 32 formed in 9%. ... 

Fig. 2.20. Effect of chain length and concentration of amine acetates on the flotation recovery of quartz (Fuerstenau, 1964).

Hagemann, J.W. W.H. Tallent K.E. Kolb. Differential scanning calorimetry of single acid tryglyc-erides Effect of chain length and unsaturation./. Am. Oil Chem. Soc. 1972, 4% 118-123. 

Barber, D. C., Whitten, D. G. (1987). Metalation of surfactant porphyrins at anionic interfaces in micelles and reversed micelles Dramatic effects of chain length and atro-pisomer structure on reactivity, /. Am. Chem. Soc., 109 6842. 

Grozema, F.C., et al. 2002. Theoretical and experimental studies of the opto-electronic properties of positively charged oligojphenylene vinylenejs Effects of chain length and alkoxy substitution. 7 Chem Phys 117 11366. 

Bazan, G.C., et al. 1996. Fluorescence quantum yield of poly(p-phenylenevinylene) prepared via the paracyclophene route Effect of chain length and interchain contacts. / Am Chem Soc 118 2618. 

MEY Meyer, D.E. and Chilkoti, A., Quantification of the effects of chain length and concentration on the thermal behavior of elastin-like polypeptides. Biomacromolecules, 5, 846, 2004. 

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