Cation-Exchange Resin Catalyzed Ketalization Reaction of Cyclohexanone with 1,4-Butanediol: Thermodynamics and Kinetics

The thermodynamics and kinetics for the ketalization reaction of cyclohexanone with 1,4-butanediol catalyzed by 732 cation-exchange resin were studied for the first time. The reaction equilibrium compositions were obtained from 293.15 to 333.15 K at atmospheric pressure, and the equilibrium constants was estimated using the UNIFAC model. The thermodynamic properties of the ketalization reaction were evaluated: Δ<i>H</i>⁰ = −12.85 kJ mol^–1, Δ<i>G</i>⁰ = −1.04 kJ mol^–1, Δ<i>S</i>⁰ = −39.61 J K^–1 mol^–1. The influences of various experimental parameters like agitation speed, initial molar ratio of reactants, temperature, catalyst loading, and particle size on the conversion of limiting reactant were studied. Different kinetic models were tested against the experimentally measured kinetic data and the results show that the Eley–Rideal model with chemisorption of 1,4-butanediol on the active sites predict the kinetics best. The <i>E</i>_a value for the overall ketalization reaction is found to be 43.89 kJ mol^–1

Calculated trapping efficiencies of a spherical particle by annular beams with different widths.

<p><b>A.</b> Axial trapping efficiency, <b>B.</b> lateral trapping efficiency. The trapping wavelength is 491 nm, the sphere radius is 2 µm, and the numerical aperture of the objective is 0.6.</p

Simulated intensity distributions of the focused annular beam with different widths.

<p><b>A.</b> Lateral intensity distribution, <b>B.</b> axial intensity distribution. The numerical aperture of the objective is 0.6.</p

Experimental layout of the trapping system.

<p>The inset gives the annular beam shape captured on Mirror 4.</p

Trapping and moving a silica microsphere axially by an objective lens with much lower NA(0.45).

<p><b>A–D</b> moving upward, <b>E–G</b> moving backward. (Video S3).</p

Pushing a silica microsphere out of the focus with the focused TEM₀₀ beam.

<p>Using a long working distance microscope objective (20X/NA0.6). (Video S2).</p

Trapping and moving a silica microsphere in 5 mm depth axially with the focused annular beam.

<p><b>A–F</b> show the trapped microsphere at different axial planes. Using a long working distance microscope objective (20X/NA0.6) (Video S1).</p

Scheme of the DMD-based LED-illumination optical sectioning SIM system.

<p>The binary fringe pattern on DMD is de-magnified and projected onto the specimen through a collimating lens and a microscope objective lens. Higher orders of spatial frequencies of the binary fringe are naturally blocked by the optics, leading to a sinusoidal fringe illumination in the sample plane. Fluorescence light from the specimen is then imaged onto the sCMOS camera.</p

3-D reconstructed images of the mixed pollen grains by using the RMS algorithm (Left) and the SHT algorithm (Right).

<p>The scale bar is 30 μm. (<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0120892#pone.0120892.s001" target="_blank">S1 Video</a>)</p

Raw image frames (a) (b) under structured illumination of the pollen grain with phase-shift by 2π/3, and the input image (c) obtained by subtracting (a) and (b).

<p>The scale bar is 5μm.</p