Synthesis and Surface Activities of Novel Succinic Acid Double‐Tailed Sulfonate Fluorinated Surfactants

Abstract

In this study, four environmentally friendly succinic acid double-tailed sulfonate fluorinated surfactants were synthesized from maleic anhydride, fluoroalkyl alcohols, namely 1-(1H,1H,7H-Dodecafluoroheptyloxy) ethanol, 1-(1H,1H,5H -octafluoropentyloxy) ethanol, 1-(1H,1H,3H-tetrafluoropropoxy) ethanol, and 1-(1H,1Htrifluoroethyoxy) ethanol, and sodium hydrogensulfite. The surfactant structure was characterized by FT-IR, 1 H NMR, and 19 F NMR . Thermogravimetric results showed that the fluorinated surfactants were stable up to relatively high temperature. The Krafft points of the four novel succinic acid double-tailed sulfonate fluorinated surfactants were all below 0°C. The lowest CMC value for the synthesized four double-tailed fluorine surfactants is about 0.076 mmol L -1 , far less than that of ammonium perfluorooctanoate (PFOA), demonstrating that double-tailed surfactants have higher surface activity than surfactants with one fluoroalkyl chain. The replacement of alkyl groups with oxyethylene groups enhances the hydrophilicity of the obtained fluorinated surfactants. Based on these findings, the synthesized surfactants may be environmentally friendly alternatives to PFOA and exhibit promising potential in industry applications.

Preparation and Insights of Smart Foams with Phototunable Foamability Based on Azobenzene-Containing Surfactants

“…The surface excess concentrations (Γ) of trans and cis-STGMAzo at the interface was calculated according to the Gibbs adsorption eq 1 17,38,39…”

“…By means of the invertible photoisomerization of the azobenzene, there exist photoswitchable surface properties of STGMAzo corresponding to a trans -rich state or cis -rich state. To research the phototriggered surface performance change phenomenon of STGMAzo, a hanging ring method was used to obtain surface tension of the STGMAzo solution with distinct concentrations. , As illustrated in Figure , the surface tension of the initial trans -STGMAzo solution decreased obviously with increasing the solution concentration and achieved a minimum equilibrium value when the solution concentration increased to 4.59 mmol·L –1 . This solution concentration (4.59 mmol·L –1 ) is defined as the CMC, and the matching surface tension at the CMC (γ CMC ) was about 47.48 mN·m –1 .…”

“…The surface excess concentrations (Γ) of trans and cis -STGMAzo at the interface was calculated according to the Gibbs adsorption eq ,, where R represents the gas constant with a value of 8.314 J·mol –1 ·K –1 , T is the absolute temperature (298.15 ± 2 K), γ shows the surface tension at different concentrations, and c expresses the concentration of STGMAzo. Among that, Γ max is defined as the maximum adsorption of STGMAzo.…”

“…The minimum area ( A min ) of per STGMAzo molecule in the surface is acquired by the maximum adsorption and Avogadro’s number ( N A ) by following eq , …”

Aggregation Behavior of “Linear” Trisiloxane Surfactant with Different Terminal Groups (CH3–, ClCH2–, and CF3−) in Aqueous Solution

“…Fluorinated surfactants, one kind of amphiphilic molecules with at least one fluorine atoms coupled to the hydrophobic group, show lower surface tension and critical micelle concentration compared with hydrocarbon and siloxane surfactants. The extraordinary physicochemical properties of fluorinated surfactants were attributed to (1) the lower polarizability of fluorine compared with hydrogen and (2) the larger molecular volume of a fluorocarbon chain. − However, the aggregation behavior of fluorinated surfactants is less often reported owing to the poor solubility, bioconcentration, and bioaccumulation. − Even so, fluorinated materials, such as fluoroalkyl sulfonates, , fluorosilicone material, − and so on, are of great interest.…”