The influence of solid-state drawing on the morphology of melt-spun poly(L-lactic acid) (PLLA) tapes, and the accompanying changes in mechanical and degradation behaviour have been studied. Mechanical properties are found to be strongly dependent on both applied draw ratio and drawing temperature. Moduli of these highly oriented tapes are significantly increased compared to as-extruded tapes at...

In the solid-state photodimerization of cinnamic acid polymorphs, can mechanical properties tell us whether Schmidt 'minimal molecular movement' or Kaupp 'molecular migration' is more important?

Cr-Tm-YAG, Cr-Tm-Ho-YAG, and Er-YAG lasers at 2.01 pm, 2.1 2pm, and 2.94 pm, resp., are compared regarding single-shot and high-repetition rate efficiency. The 2 pm lasers are intrinsically limited at higher operation temperatures, the Er-laser only shows thermal lensing. Th~n (3 mm) Tmand Ho-laser rods allow high repetition rates (30 Hz) and with increasing rod diameters pulse energies up to 1...

Photoluminescence excitation spectroscopy is a contactless characterization technique that can provide valuable information about the surface and bulk recombination parameters of a semiconductor device, distinct from other sorts of photoluminescent measurements. For this technique, a temperature-tuned light emitting diode (LED) has several advantages over other light sources. The large radiatio...

[structure: see text] A series of novel extended pi-conjugated twin molecules based on 10,15-dihydro-5H-diindeno[1,2-alpha;1',2'-c]fluorene (truxene) have been prepared via Pd(0)-catalyzed Suzuki coupling, Sonogashira coupling, and McMurry reactions, respectively. 9,9'-Spirobifluorenylene, ethynylene, and vinylene groups as the bridge are introduced to connect both truxene moieties to understan...

A bright blue fluorescent graphene oxide that originates from passivation of surface reactive sites by amide formation and ring-opening amination of epoxide has been prepared. The surface polarity and charges of the fluorescent graphene oxide can synchronously be tuned by varying the used alkylamines.

Novel indeno[1,2-b]benzo[4,5-e]pyran-11-one-type fluorophores exhibiting intense solid-state fluorescence were conveniently synthesized and the relation between their solid-state photophysical properties and the X-ray crystal structures were investigated, which demonstrates that non-planar structures with sterical hindered substituents prevent the fluorophores from forming short pi-pi contacts ...

a simple, efficient and clean procedure has been developed for the cleavage of imines c=n bond. deprotection of imines to their parent carbonyl and amine compounds was achieved using p-toluenesulfonic acid in the solid state condition at 25-45 ˚c. the salient features of this methodology are shorter reaction times, cheap processing, high yields of product and easy availability of the catalyst. ...