Mechanocatalytic Production of Lactic Acid from Glucose by Ball Milling

ZSM-5 zeolites are commonly used as a heterogeneous catalyst for reactions. Four ZSM-5 catalysts (with various crystallite sizes and a similar ratio of Si/Al) and their ball-milling/surface-poisoning derivates were used to convert L-lactic acid to L, L-lactide. The reaction products were analyzed by three independent analytical methods (i.e., Proton nuclear magnetic resonance (1H NMR), high-pressure liquid chromatography (HPLC), and chiral gas chromatography (GC)) for determining the L, L-lactide yield and L-lactic acid conversion. A clear size effect, i.e., smaller catalysts providing better performance, was observed. Further ball-milling/surface-poisoning experiments suggested that the size effect of the ZSM-5 catalysts originated from the diffusion-controlled nature of the reaction under the investigated conditions.

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Mechanochemical synthesis of poly(lactic acid) block copolymers: overcoming the miscibility of the macroinitiator, monomer and catalyst under solvent-free conditions

Polymer Chemistry ◽

10.1039/c8py01520a ◽

2019 ◽

Vol 10 (4) ◽

pp. 539-545 ◽

Cited By ~ 11

Author(s):

Gue Seon Lee ◽

Bo Reum Moon ◽

Haemin Jeong ◽

Jihoon Shin ◽

Jeung Gon Kim

Keyword(s):

Lactic Acid ◽

Block Copolymers ◽

Ball Milling ◽

Mechanochemical Synthesis ◽

Solvent Free ◽

Poly Lactic Acid ◽

Energy Delivery ◽

Solvent Free Conditions

Efficient mixing and energy delivery by ball-milling promoted the lactide polymer growth from macroinitiators without the use of a solvent.

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Demonstration of Retinal Glycogen with Silver Methenamine

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100066875 ◽

1971 ◽

Vol 29 ◽

pp. 564-565

Author(s):

A. W. Sedar ◽

G. H. Bresnick

Keyword(s):

Lactic Acid ◽

Chromic Acid ◽

Periodic Acid ◽

Müller Cell ◽

External Limiting Membrane ◽

Electron Microscope Level ◽

Reactive Process ◽

Inner Limiting Membrane ◽

Muller Cell ◽

And Migration

After experimetnal damage to the retina with a variety of procedures Müller cell hypertrophy and migration occurs. According to Kuwabara and others the reactive process in these injuries is evidenced by a marked increase in amount of glycogen in the Müller cells. These cells were considered originally supporting elements with fiber processes extending throughout the retina from inner limiting membrane to external limiting membrane, but are known now to have high lactic acid dehydrogenase activity and the ability to synthesize glycogen. Since the periodic acid-chromic acid-silver methenamine technique was shown to demonstrate glycogen at the electron microscope level, it was selected to react with glycogen in the fine processes of the Müller cell that ramify among the neural elements in various layers of the retina and demarcate these cells cytologically. The Rhesus monkey was chosen as an example of a well vascularized retina and the rabbit as an example of a avascular retina to explore the possibilities of the technique.

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