Adsorption of Aroma Chemicals on Cotton Fabric in Different Aqueous Environments

Abstract

Surfactants enhance adsorption of an aroma chemical on cotton fiber. Strong hydrophobic and electrostatic interactions between surfactant and fiber substrate result in higher adsorption of surfactant/aroma chemical aggregates than for the aroma chemical alone, with higher adsorption for cationic systems than for anionic systems. Adsorption is attributed to solution physical entrapment, hydrophobic interaction, dispersion forces, and interaction with surfactant molecules adsorbed on fiber. Log P and water solubility are important factors in aroma chemical adsorption. Hydrophobicity increased selective partitioning of aroma chemicals on the fiber surface particularly in the presence of surfactants. Statistical analyses indicate some evidence of polar-polar interaction between aroma chemicals and cellulose. With no surfactant, more adsorption is often observed in systems with a higher concentration of NaCl. The screening effect of electrolytes increases with the electrolyte reducing the energy of the liquid-solid interface. Lower interfacial energy results in increased adsorption of an aroma chemical on the fiber surfaces. Electrolyte screening affects aroma chemical adsorption most for anionic surfactant systems. Increase in the concentration of the electrolyte increases the screening effect that reduces the repulsive forces between the anionic molecules and weakly electronegative cotton fiber surfaces. In a cationic system, the screening effect of the electrolyte reduces adsorption of aroma chemicals with increased electrolyte concentration, due to the screening-reducing attraction between cationic surfactant molecules and the fiber surface. Chemical functionality shows a significant effect (alkanol C ketone C aldehyde [ ester) on adsorption. Adsorption increased with increasing molecule ovality. Statistical analyses indicate that molecular shape within a chemical class of compounds influences adsorption of the aroma chemical.

Controlled fragrance release from galactose-based pro-fragrances

“…The protected and therefore more hydrophobic pro-fragrance 2 gave the best results in the soener release test. This observation is also supported by earlier studies for apolar molecules 24 and polymers 13 where the deposition of hydrophobic compounds is more efficient than the one for hydrophilic ones. Taking in account the release data from the direct deposition, profragrance 3 shows the highest release aer three days, due to the more hydrophilic nature of the backbone molecule.…”

“…16,32 Another well-known effect of the surfactant, besides acting as a soener which smoothens the fabric, is its ability to facilitate the deposition of nonpolar molecules onto the cotton surface. 24 Thus, cotton sheets were washed with aqueous mixtures comprising the surfactant and either of the profragrances, wringing the wet tissue to a pre-dened weight, and drying the samples for three days in a dark cupboard (Fig. 1).…”

“…The free hydroxyl groups can serve to covalently attach the payload, as well as auxiliary chemical motifs which may serve as anchors, solubilizing groups, or to change the polarity of the substrate from hydrophilic to hydrophobic. As it has been shown that the polarity of the structure can signicantly inuence the deposition of a pro-fragrance onto a substrate and also affect the release kinetics, 13,24 this latter feature appears to be particularly important for practical applications. The polarity of fragrance molecules can be expressed by the log P o/w which is the logarithmic octanol/water partition coefficient, 25,26 which can be calculated from the chemical structure.…”

Adsorption of alkyl-dimethyl-benzyl-ammonium chloride on differently pretreated non-woven cotton substrates

“…The adsorption of both ionic and non-ionic surfactants onto solid cellulosic surfaces has been extensively studied over the years using a wide variety of experimental techniques. [4][5][6][7][8][9][10][11][12][13][14][15] Factors such as the structure of the surfactant, the structural groups on the solid surface, and the chemical and physical properties of the bulk solution have been found to affect surfactant adsorption on cellulosic surfaces. Early research by Weatherburn and Bayley 16 and Ginn et al 17 has shown that ionic surfactants adsorb more readily than non-ionic compounds, with cationic surfactants having the highest rate of adsorption on cellulosic surfaces.…”

Preparation, vibrational structure and dielectric properties studies of cotton linter and its derivatives

“…Many review articles were studied the dielectric dynamic spectroscopy of the pure polysaccharides like cellulose and their derivatives [13][14][15][16][17][18][19][20][21][22]. Dielectric relaxation separates different molecular groups of a repeating unit of a polymer with respect to the rate of its orientation dynamics were studied [23][24][25][26][27][28].…”