Surface activities and thermodynamic properties of novel cationic surfactants with hydroxymethyl group

<p>A new series of cationic surfactants, <i>N</i>–alkyl–<i>N,N</i>–dimethyl–<i>N</i>–(<i>p</i>–(hydroxymethyl) benzyl) ammonium chlorides (<i>p</i>-DHBA<i>-m</i>), were synthesized and the structures were characterized by ¹HNMR, ¹³CNMR, FT–IR and ESI–MS. The surface activities, thermodynamic properties and aggregation behaviors of <i>p</i>-DHBA<i>-m</i> in aqueous solutions were respectively studied by means of surface tension, isothermal titration calorimetry and steady-state fluorescence methods. Thermodynamic parameters show that the micellization is an entropy-driven process. According to the fluorescence quenching method, the micelle aggregation numbers (<i>N</i>_agg) of <i>p</i>-DHBA-<i>m</i> were calculated and found that the increase of temperature or the elongation of alkyl chain length could lead to the reduction of the <i>N</i>_agg, respectively.</p

The list of <i>static attributes.</i>

<p>The list of <i>static attributes.</i></p

The mechanism of self-scheduling.

<p>The flow lines with the same color represent the same execution flow and the circled numbers show execution orders with the same functional module.</p

The chart of <i>TTG</i>.

<p>The abscissa represents the execution time while the ordinate represents the execution threads. The representation [a]b:c on the ordinate indicates parent thread number, level number and current thread number respectively, which could clearly represent the cases of multiple parallel regions and parallel region nesting. The legend explains the used colors related to various task behaviors shown in this chart. TaskID ([E] indicates explicit task instances while [I] represents implicit ones) will be displayed on the rectangular bar in the graph until its length reaches a threshold. In addition, this chart can be scaled for easy viewing.</p

The case of <i>RDRP</i> instances.

<p>Task0 is the implicit task instance, while the others are explicit ones.</p

The task execution mechanism of GCC.

<p>The task execution mechanism of GCC.</p

The comparison chart with the counts of task instances and taskwait.

<p>The abscissa represents the execution program, while the numbers of task instances and taskwait operation are represented on the ordinate.</p

The list of <i>execution states.</i>

<p>The list of <i>execution states.</i></p

The description of <i>Redundancy Pruning Method</i> (<i>RPM</i>) (Algorithm 1).

<p>Algorithm 1: For each task instance, a property of <i>bar</i> means whether it has a synchronization point caused by barrier directive, while the property of <i>tw</i> means whether it has a synchronization point caused by taskwait directive; <i>n</i>: the number of task instances.</p

The monitoring principle diagram.

<p>The monitoring principle diagram.</p