Dependence of the dimension of the associates of water-soluble tris-malonate of light fullerene C60[=C(COOH)2]3 in water solutions at 25 °C

Abstract

Dependence of the dimension of the associates of water-soluble tris-malonate of light fullerene -C 60 [= C(COOH) 2 ] 3 in water solutions at 25 • C Investigation of the concentration dependence of the size and type C 60 [=C(COOH) 2 ] 3 aggregation in aqueous solutions at 25 • C was accomplished with the help of a dynamic light scattering method. It was determined that three types of aggregates are realized in the solutions. The average number of C 60 [=C(COOH) 2 ] 3 molecules in smaller aggregates and all types of aggregates were calculated. One can see that over the whole concentration range, from 0.01 to 10 g/dm 3 , aqueous solutions of C 60 [=C(COOH) 2 ] 3 are characterized by sub-micro-heterogeneous behavior (because second-type aggregates with the linear dimensions -hundreds of nm are formed in all solutions). Additionally, the most concentrated solution (C = 10 g/dm 3 ) is characterized by micro-heterogeneous or colloid behavior (because third-type aggregates with the linear dimensions on the order of µm -are formed). In order to describe or explain such behavior, a stepwise aggregation model was invoked.Keywords: tris-malonate of light fullerene, method of the dynamic light scattering.

Mass transport properties of water soluble light fullerene tris-malonate C60[=C(COOH)2]3 in aqueous solutions

“…In the case of our water soluble light fullerene derivatives, one can expect a higher degree of association and hydration, which was proven earlier by light scattering experiments [5]. In that work, the formation of three types of aggregates was observed with the following characteristic radii: r D ≈ 20 -40 nm (for type 1 aggregates), r D ≈ 150 -250 nm (for type 2 aggregates), r D ≈ 2000 -3000 nm (for type 3 aggregates).…”

“…This article furthers the investigations which were initiated previously [1][2][3][4][5], devoted to describing the synthesis and identification of the C 60 [=C(COOH) 2 ] 3 tris-malonate [1] (the original synthesis of this water soluble derivative was described earlier in [5]), the investigation of volume and refraction properties of its aqueous solutions at 25…”

“…• C [2], poly-thermal solubility and complex thermal analysis [3], the concentration dependence of electric conductivity and pH for aqueous solutions [4], and concentration dependence of the last-mentioned properties for C 60 [=C(COOH) 2 ] 3 aggregates [5].…”

Cryometry and excess functions of fullerenols and trismalonates of light fullerenes – C60(OH) and C70[=C(COOH)2]3 aqueous solutions

“…Visible light scattering analysis in light fullerenols (trismalonates) -H 2 O solutions at room temperature was provided repeatedly (see [1,5,14]). In all cases, one can see the following:…”

“…This article is the continuation of a series of articles devoted to the synthesis, identification and physico-chemical properties investigation of nanoclusters, which represented the moderately water soluble derivatives of light fullerenes C 60 and C 70 [1][2][3][4][5][6][7][8][9][10][11][12][13][14] -poly-hydroxyl fullerenols (fullerenol-d C 60 (OH) 24±2 and malonic ester -trismalonate C 70 [=C(COOH) 2 ] 3 ). In previous articles' authors have reported on the volume, refraction, electrical, transport properties of these water soluble nanoclusters and their aqueous solutions, also investigations of solubility in water in poly-thermal conditions and in some ternary water-salt systems and complex thermal analysis of nanocluster crystal-hydrates were performed.…”