scholarly journals Thermal properties and surface chemistry of cotton varieties mineralized with calcium carbonate polymorphs by cyclic dipping

RSC Advances ◽  
2020 ◽  
Vol 10 (58) ◽  
pp. 35214-35225
Author(s):  
Sunghyun Nam ◽  
Yaewon Park ◽  
Matthew B. Hillyer ◽  
Rebecca J. Hron ◽  
Nicholas Ernst ◽  
...  

Hydroentangled nonwovens of raw white cotton fiber, scoured white cotton fiber, and raw brown cotton fiber are effective hosts for mineralization of calcium carbonate polymorphs to modify and improve their thermal and surface properties.

2018 ◽  
Author(s):  
Bryan C. Chakoumakos ◽  
◽  
Brenda M. Pracheil ◽  
R. Seth Wood ◽  
Alison Loeppky ◽  
...  

2021 ◽  
pp. 117040
Author(s):  
Jingzhong Kuang ◽  
Xiaoyuan Wang ◽  
Mingming Yu ◽  
Weiquan Yuan ◽  
Zheyu Huang ◽  
...  

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Michael B. Toffolo ◽  
Giulia Ricci ◽  
Luisa Caneve ◽  
Ifat Kaplan-Ashiri

Abstract In nature, calcium carbonate (CaCO3) in the form of calcite and aragonite nucleates through different pathways including geogenic and biogenic processes. It may also occur as pyrogenic lime plaster and laboratory-precipitated crystals. All of these formation processes are conducive to different degrees of local structural order in CaCO3 crystals, with the pyrogenic and precipitated forms being the least ordered. These variations affect the manner in which crystals interact with electromagnetic radiation, and thus formation processes may be tracked using methods such as X-ray diffraction and infrared spectroscopy. Here we show that defects in the crystal structure of CaCO3 may be detected by looking at the luminescence of crystals. Using cathodoluminescence by scanning electron microscopy (SEM-CL) and laser-induced fluorescence (LIF), it is possible to discern different polymorphs and their mechanism of formation. We were thus able to determine that pyrogenic calcite and aragonite exhibit blue luminescence due to the incorporation of distortions in the crystal lattice caused by heat and rapid precipitation, in agreement with infrared spectroscopy assessments of local structural order. These results provide the first detailed reference database of SEM-CL and LIF spectra of CaCO3 standards, and find application in the characterization of optical, archaeological and construction materials.


Processes ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 167 ◽  
Author(s):  
Bo Huang ◽  
Guowei Liu ◽  
Penghui Wang ◽  
Xiang Zhao ◽  
Hongxiang Xu

The objective of this research was to explore the changes of the pore structure and surface properties of nitric-modified lignite and base the adsorption performance on physical and chemical adsorbent characteristics. To systematically evaluate pore structure and surface chemistry effects, several lignite samples were treated with different concentrations of nitric acid in order to get different pore structure and surface chemistry adsorbent levels. A common heavy metal ion contaminant in water, Pb2+, served as an adsorbate probe to demonstrate the change of modified lignite adsorption properties. The pore structure and surface properties of lignite samples before and after modification were characterized by static nitrogen adsorption, X-ray diffraction, Scanning electron microscope, Fourier transform infrared spectroscopy, zeta potential, and X-ray photoelectron spectroscopy. The experimental results showed that nitric acid modification can increase the ability of lignite to adsorb Pb2+. The adsorption amount of Pb2+ increased from 14.45 mg·g−1 to 30.68 mg·g−1. Nitric acid reacted with inorganic mineral impurities such as iron dolomite in lignite and organic components in coal, which caused an increase in pore size and a decrease in specific surface areas. A hydrophilic adsorbent surface more effectively removed Pb2+ from aqueous solution. Nitric acid treatment increased the content of polar oxygen-containing functional groups such as hydroxyl, carbonyl, and carboxyl groups on the surface of lignite. Treatment introduced nitro groups, which enhanced the negative electrical properties, the polarity of the lignite surface, and its metal ion adsorption performance, a result that can be explained by enhanced water adsorption on hydrophilic surfaces.


2012 ◽  
Vol 573-574 ◽  
pp. 167-173
Author(s):  
Li Qin Lou

Kapok fiber has many excellent Performances. the surface and cross section of the kapok fiber were observed. These performances of the distribution of length and fineness, moisture regain, acid and alkali properties, and dyeing property were tested and compared for the kapok fiber, colored cotton fiber and white cotton fiber. The fabrics of same weave structure paramater were developed and the warmth retention property wewe tested. The results show that the surface of the kapok fiber is smooth,Cross section of the kapok fiber is round with hollow-structure. The length and fineness of the kapok fiber was lower than white cotton fiber and colored cotton fiber. The hygroscopicity and moisture guide properties of the kapok fiber was better than white cotton fiber and colored cotton fiber, the dyeing property of the kapok fiber was worse than white cotton fiber, the kapok fiber is alkali-resistance and non acid-resistant. The fabrics of the kapok fiber has better warmth retention property.


2005 ◽  
Vol 11 (S03) ◽  
pp. 162-165 ◽  
Author(s):  
L. von Mühlen ◽  
R. A. Simao ◽  
C. A. Achete

Surface chemistry and topography of materials are generally preponderant factors in a series of material properties, such as adhesion, wettability, friction and optical properties [1]. Wettability of films, for example, can be altered significantly by modifying its surface roughness and also by incorporating functional groups. Plasma treatment is a powerful and versatile way to modify surface properties of amorphous nitrogen-incorporated carbon thin films (a-C:H(N)) and obtain materials with improved properties, once it is possible to modify the surfaces in a controlled way by specific settings of plasma conditions. [2 - 4]


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