The effect of agitator speed, duration of agitation, xylene concentration in the membrane phase, membrane to external phase (M/E) ratio on the reduction of solute, concentration of biological oxygen demand (BOD) and chemical oxygen demand (COD) in the external phase has been studied.
The effect of contact time is to ensure that the duration of agitation time is sufficient to attain the equilibrium of the adsorption process.
The effects of pH (2 9), ionic strength (0 0.8 mol L−1), dye concentrations (20 500 mg L−1), and duration of agitation (0 180 min) were investigated.
(A, B, C) The effect of duration of homogenization, agitation speed and volume ratio of organic solvent phase to external aqueous phase on the mean particle size.
(D, E, F) The effect of duration of homogenization, agitation speed and volume ratio of organic solvent phase on the (EE)%.
Figure 1D,E,F indicates the effect of duration of homogenization, agitation speed and volume ratio of organic solvent phase to external aqueous phase on entrapment efficiency.
The reaction was carried out in a high pressure kettle, and seven parameters, including the sample to acidic solution ratio, concentration of H2SO4 aqueous solution, volume of extraction solvent, reaction temperature, duration of hydrolysis, agitation speed and boiling point of petroleum ether, were sequentially optimized through single factor experimental design.
Rotatable central composite design (RCCD) and response surface methodology (RSM) were used to investigate and optimize the impact of critical factors, namely duration of homogenization, agitation speed and volume ratio of organic solvent phase to external aqueous phase, on the response properties of the yielded NPs, such as mean particle size and entrapment efficiency [11, 12].
The obtained polynomial equations were further analyzed using RSM, and the three-dimensional surface plots were generated to describe the mathematical models (Figure 1). Figure 1A,B,C displays the effect of duration of homogenization, agitation speed and volume ratio of organic solvent phase to external aqueous phase on the mean particle size.
We documented total duration of PR, Sedation Agitation Scale (SAS) scores and presence of delirium (Intensive Care Delirium Screening Checklist score ≥4).
Figure 1D shows that an increase in either duration of homogenization or agitation speed all results in proportionate decrease in the entrapment efficiency.
