Synthesis of trisiloxane-tailed surface active ionic liquids and their aggregation behavior in aqueous solution

Modern Room Temperature Ionic Liquids, a Simple Guide to Understanding Their Structure and How It May Relate to Dynamics

“…We now have task specific ionic liquids, [1][2][3][4][5][6][7][8][9][10][11] ionic liquid drugs, 12-16 ionic liquids for energy applications such as batteries and supercapacitors, 17-31 those that capture carbon dioxide 3,32-38 and those that dissolve cellulose [39][40][41][42][43][44] and proteins. [45][46][47][48][49] In terms of their structure, interesting work has surfaced on protic ionic liquids, [50][51][52][53][54][55][56][57][58][59] ILs that are highly fluorinated, 59-63 ILs with polar tails, [64][65][66][67] ILs with paramagnetic ions, 68,69 those containing silicon, [70][71][72][73][74] and some that are triphillic 59,61-63 just to mention a few examples. Not all ionic liquids but a vast number of them can be categorized as having both charged components and also apolar components.…”

Synthesis and Aggregation Behavior of Trisiloxane Ionic Liquids in Aqueous Solution

“…As seen in Table , the CMC value of Si 3 PyCl‐EO 3 (4.3 mM) was smaller than that of Vi‐Si 3 PyCl (13.5 mM), caused by the introduction of two CH 2 CH 2 SCH 2 CH 2 groups for the hydrophobic parts. However, the surface tension at CMC ( γ CMC ) was 33.5 mN m −1 and higher than that of Vi‐Si 3 PyCl and even trisiloxane and tetrasiloxane ionic liquids reported by Du et al () and Tan and Feng (). Generally, siloxane surfactants have lower γ CMC values attributed to the unique flexibility of the Si–O–Si backbone, which causes siloxane surfactants to adopt various configurations and form dense surface films packed with methyl groups on the air/solution interface (Tan et al, , ).…”

“…A higher Α min value or a lower Γ max value revealed a looser arrangement of trisiloxane ionic liquids molecules at the surface (Tan et al, ). The Α min value of Si 3 PyCl‐EO 3 was 127.8 Å 2 , and is larger than those of cationic trisiloxane surfactants, i.e., 1‐methyl‐1‐[bis(trimethylsiloxy)methyl]silylpropylpyridinium chloride ( Α min = 111 Å 2 ) (Du et al, ) and Vi‐Si 3 PyCl ( Α min = 81.8 Å 2 ). The reason may be that the steric hindrance of CH 2 CH 2 SCH 2 CH 2 for Si 3 PyCl‐EO 3 .…”

“…Similar to hydrocarbon IL surfactants, siloxane IL surfactants have attracted considerable attention attributed to their high surface activity, low toxicity, and biocompatibility (Hill, ; Hill, ). Du et al () demonstrated that the surface activities of trisiloxane‐based ionic liquids were superior to that of 1‐dodecyl‐3‐methylimidazolium chloride (C 12 mimCl) and that trisiloxane‐based ionic liquids can form vesicular‐like aggregates. Tan and Feng () prepared tetrasiloxane‐based ionic liquids with different counterions, NO 3 − , Cl − , and CH 3 COO − , in general, the structure of counterions could greatly affect the surface activities and aggregation behavior of the ionic liquid.…”

Effect of Sodium Halide on Micellar and Surface Properties of Cationic Silicone Surfactants

“…The aggregation behavior of cationic silicone surfactants in aqueous solution has been widely investigated in recent years. Du et al () and Li et al () reported that trisiloxane cationic surfactants can form vesicular aggregates with diameters from 20 to 200 nm. Fang et al (, ), Tan et al (, ) and Tan and Feng () reported that a series of cationic silicone surfactants have excellent surface activities.…”