Surface Chemistry in Environmental Degradation of Polymeric Solids.

Microplastics (MPs) cause significant adverse environmental effects. To address this issue, a scientific approach for understanding the formation of MPs is essential. In this Perspective, we summarize the three typical degradation behaviors of polymeric solids from a surface chemistry perspective: chemical degradation, biodegradation, and mechanical degradation.

Critical Involvement of Environmental Carbon Dioxide Fixation to Drive Wax Ester Fermentation in Euglena.

Accumulation profiles of wax esters in Euglena gracilis Z were studied under several environmental conditions. The highest amount of total wax esters accumulated under hypoxia in the dark, and C28 (myristyl-myristate, C14:0-C14:0) was prevalent among all conditions investigated. The wax ester production was almost completely suppressed under anoxia in the light, and supplying exogenous inorganic carbon sources restored wax ester fermentation, indicating the need for external carbon sources for the wax ester fermentation.

Novel SiO2-deposited CaF2 substrate for vibrational sum-frequency generation (SFG) measurements of chemisorbed monolayers in an aqueous environment.

A novel SiO(2)-deposited CaF(2) (SiO(2)/CaF(2)) substrate for measuring vibrational sum-frequency generation (SFG) spectra of silane-based chemisorbed monolayers in aqueous media has been developed. The substrate is suitable for silanization and transparent over a broad range of the infrared (IR) probe. The present work demonstrates the practical application of the SiO(2)/CaF(2) substrate and, to our knowledge, the first SFG spectrum at the solid/water interface of a silanized monolayer observed over the IR fingerprint region (1780-1400 cm(-1)) using a back-side probing geometry.

Dimerization and double proton transfer-induced tautomerism of 4(3H)-pyrimidinone in solution studied by IR spectroscopy and quantum chemical calculations.

The tautomerism and dimerization of 4(3H)-pyrimidinone (4(3H)Pyr) in carbon tetrachloride (CCl4) and chloroform (CHCl3) solutions were investigated using IR spectroscopy and quantum chemical calculations. The observed IR spectra in the NH and OH stretching regions clearly revealed the predominance of the keto tautomer in both solvent systems. The enol form only exists in a very small proportion in the CCl4 solution.

Melting behavior of poly(3-hydroxybutyrate) investigated by two-dimensional infrared correlation spectroscopy.

The melting behavior of a bacterially synthesized biodegradable polymer, poly(3-hydroxybutyrate) (PHB), was investigated by using generalized two-dimensional infrared (2D IR) correlation spectroscopy. Temperature-dependent spectral variations in the regions of the C-H stretching (3100-2850 cm(-1)), C=O stretching (1800-1680 cm(-1)), and C-O-C stretching (1320-1120 cm(-1)) bands were monitored during the melting process. The asynchronous 2D correlation spectrum for the C=O stretching band region resolved two crystalline bands at 1731 and 1723 cm(-1).