Abstract A low-crystallinity index chalcedony was found in the rhyolitic ignimbrite of Late Jurassic Zhangjiakou Formation, located Longhua County, Hebei Province, China. This occurs as fillings along fragile fractures host rock and is distinct from any other deposits, such known basalt carbonate-related types. The ignimbrite, comprising sanidine (50–70 vol.%), plagioclase (10–15 quartz (8–10 m...

The near infrared (NIR) spectroscopy presents itself as an interesting non-destructive test tool as it enables a fast, simple and reliable way for characterizing large samplings of biological materials in a short period of time. This work aimed to establish multivariate models to estimate the crystallinity indices and tensile and burst strength of cellulosic and nanocellulosic films through NIR...

Corncob is one of the industrial waste has cellulose content of 39.1 wt%, which makes it has high potential to be a raw material in the production of cellulose nanocrystal. Corncob was delignificated with 3.5 wt% HNO3 and NaNO2 10 mg, precipitated process with 17.5 wt% NaOH, and bleached with 10 wt% H2O2. Cellulose nanocrystal was obtained by hydrolysis using 45 wt% H2SO4. Corncob and cellulose...

The preparation of nanocellulose via Cr(NO3)3-assisted sulfuric acid hydrolysis was optimized using response surface methodology (RSM). The experiment was performed using a five-level, four-factor central composite design coupled with RSM in order to optimize nanocellulose crystallinity and product yield. Four factors were evaluated for the preparation of nanocellulose: (1) reaction temperature...

Raman and Fourier Transform Infrared (FT-IR) spectroscopy was used for assessment of structural differences of celluloses of various origins. Investigated celluloses were: bacterial celluloses cultured in presence of pectin and/or xyloglucan, as well as commercial celluloses and cellulose extracted from apple parenchyma. FT-IR spectra were used to estimate of the I(β) content, whereas Raman spe...

Changes in the physical properties of pulp during recycling are sometimes reported to be caused by changes in chemical properties offibres. In order to determine the relationship, if any, between physical and chemical properties, a chemical characterization was carried out of several recycled pulps. Measurements of carbohydrates, lignin, crystallinity index, and DP of cellulose were carried out...

Changes of the pore structure of recycled fibers and the strength properties of papers produced by old corrugated container (OCC) recycled fibers were studied, after they were subjected to different stock preparation and papermaking processes. In this paper, the effects of beating, sizing, pressing, and drying on fiber properties were investigated, and the porous structure of fibers was analyze...

The grade of a quartz ore is not a measure of its chemical reactivity. A high grade quartz sample (B) showed low reactivity in sodium silicate production. Structural imperfection usually occurs due to lattice defects in the quartz tetrahedron as a result of several substitutions that happen during mineralization. The random distortion of the quartz tetrahedron that could be affected by various ...

Oil palm ash (OPA), a bio-agricultural waste from oil palm mills, was subjected to high-energy ball milling for 30 h and was converted into a nano-structured material. The nano-structured OPA was characterized for its particle size and crystallinity index by using Transmission Electron Microscopy (TEM) and X-ray Diffraction (XRD) analysis. The crystallite size obtained from TEM and XRD was foun...