Perfect crystallinity is defi ned as three-dimensional, atomiclevel periodic order in a material. [ 1 ] The degree of crystallinity can be strongly affected by the specimen’s formation process and often plays an important role in its resulting chemical and mechanical properties. Calcium carbonate (CaCO 3 ), for example, exhibits a wide range of gradually changing crystallinity. The two extremes...

Enzymatic hydrolysis of cellulose in plant and wood cell walls is expected to be affected by its chemical composition as well as structural and morphological features. In the present study, different crystallinity cellulose samples and varying size fractionated loblolly pine wood cell wall particles were hydrolyzed using a mixture of Celluclast and Novozyme 188. In pure cellulose samples of Wha...

Poly(l-lactide) electrospun mats with random and aligned fiber orientation and films have been produced with degrees of crystallinity ranging from 0 up to nearly 50%. The overall surface roughness is practically constant irrespective of the sampling areas (1 × 1 µm to 20 × 20 µm) for degrees of crystallinity below 30%, increasing for higher degrees of crystallinity for the larger sampling areas...

Chitosan fiber mats were successfully processed by electrospinning. The as-spun fiber mats were neutralized with ethanol and cross-linked with glutaraldehyde. A decrease of the fiber average diameter from 243 ± 43 nm down to 215.53 nm was observed for the neutralized and cross-linking chitosan membrane. It was found that the processing conditions do not alter the initial deacetylation degree of...

For biodegradable polymers such as poly (Llactic acid) (PLLA), material crystallinity has a considerable effect on degradation and physical properties. In this work, the effects of laser fluence of a 355 nm UV Q-switched Nd-YAG laser on the crystallinity and conformation at the surface of PLLA films and the factors affecting the transformation are investigated. Electron microscopy, X-ray diffra...

The aims of this study were to evaluate the effects of CPP method on the crystallinity of apatite powder and on the acid resistance of bovine enamel. Crystallinity degrees of apatite powder before and after CPP treatment were measured by powder X-ray diffraction analysis. Polished bovine enamel specimens treated with CPP method or NaF were immersed in a lactic acid solution for up to five days....

The small punch test is widely used to characterize the ductility and fracture resistance in metals and ceramics, when only a small volume of material is available. This study was conducted to investigate the suitability of the small punch test for characterizing polyetheretherketone (PEEK) polymeric biomaterials for changes in material grade, crystallinity, and molding process. The small punch...

The crystallinity of epitaxial graphene (EG) grown on a Hexagonal-SiC substrate is found to be enhanced greatly by capping the substrate with a molybdenum plate (Mo-plate) during vacuum annealing. The crystallinity enhancement of EG layer grown with Mo-plate capping is confirmed by the significant change of measured Raman spectra, compared to the spectra for no capping. Mo-plate capping is cons...

The influence of wood components and cellulose crystallinity on the thermal degradation behavior of different wood species has been investigated using thermogravimetry, chemical analysis and X-ray diffraction. Four wood samples, Pinus elliottii (PIE), Eucalyptus grandis (EUG), Mezilaurus itauba (ITA) and Dipteryx odorata (DIP) were used in this study. The results showed that higher extractives ...