The effect of polyoxypropylene chain length in nonionic surfactants on their adsorption at the aqueous solution-air interface was written by Sokolowski, A.;Chlebicki, J.. And the article was included in Tenside Detergents in 1982.Reference of 20324-33-8 This article mentions the following:
Surface tension isotherms were determined for alkyl monoethers CnH2n+1(OCH2CH(CH3))zOH (n = 1-4; z = 1-7) at the aqueous solution- air interface by the maximum bubble pressure method at 293.2 K. A quant. correlation was found between adsorption free energy and monoether structure for surface tension decrease of â?0 Ã 10-3 Nm-1. Interaction of both alkyl and polyoxypropylene chains is statistically significant and affects the adsorption free energy. The CH2 and P:O group contributions to the free energy of adsorption were calculated for various values of surface tension decrease. In the experiment, the researchers used many compounds, for example, 1-((1-((1-Methoxypropan-2-yl)oxy)propan-2-yl)oxy)propan-2-ol (cas: 20324-33-8Reference of 20324-33-8).
1-((1-((1-Methoxypropan-2-yl)oxy)propan-2-yl)oxy)propan-2-ol (cas: 20324-33-8) belongs to ethers. Ether is less polar than esters, alcohols or amines because of the oxygen atom that is unable to participate in hydrogen bonding due to the presence of bulky alkyl groups on both sides of the oxygen atom. Ethers feature bent C–O–C linkages. In dimethyl ether, the bond angle is 111° and C–O distances are 141 pm. The barrier to rotation about the C–O bonds is low. The bonding of oxygen in ethers, alcohols, and water is similar. In the language of valence bond theory, the hybridization at oxygen is sp3.Reference of 20324-33-8
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem