Al-substitution-induced defect sites enhance adsorption of Pb2+ on hematite

2019 ◽  
Vol 6 (5) ◽  
pp. 1323-1331 ◽  
Author(s):  
Yu Liang ◽  
Mingxia Wang ◽  
Juan Xiong ◽  
Jingtao Hou ◽  
Xiaoming Wang ◽  
...  

Al-substitution induces Fe vacancies on hematite (001) facets, which contributes substantially to increase the surface reactivity of hematite.

2019 ◽  
Vol 6 (12) ◽  
pp. 3625-3637 ◽  
Author(s):  
Jinling Xu ◽  
Luuk K. Koopal ◽  
Mingxia Wang ◽  
Juan Xiong ◽  
Jingtao Hou ◽  
...  

Natural goethite commonly encounters Al substitution for Fe, which alters the surface reactivity of goethite.


1971 ◽  
Vol 44 (2) ◽  
pp. 307-343 ◽  
Author(s):  
Donald Rivin

Abstract Carbon surface chemistry is relatively new as an independent subject of inquiry, and, judging by the volume of publications, is receiving increasing attention throughout the world. Our conception of carbon black and its functional behavior has changed significantly since the pioneering publication by Studebaker in 1957. Within the last few years there have been a number of excellent reviews covering various aspects of carbon chemistry by authors who are presently active in this field. Donnet, Puri, and Boehm discuss reactions of carbon and the characterization of surface functional groups while van der Plas is particularly thorough on the subject of adsorption properties and porosity. Deviney explores the relationship between surface chemistry and carbon-elastomer interactions, as does Studebaker from the point of view of the practical application of carbon black in rubber. Current monographs containing useful background information are collected in “Les Carbones” and in Walker's continuing series, “Chemistry and Physics of Carbon”. This review will describe how information from diverse sources has contributed to our understanding of the surface reactivity and fundamental adsorption behavior of carbon. It will be shown that most properties of carbon blacks are consistent with a surface structure wherein large deformed basal layers conforming to the topography of the surface are composed of several planar aromatic domains with functional groups at edge and defect sites. Examples of strong molecular interactions are given which involve specific reaction with the basal surface, individual functional groups, or a combination of both.


2020 ◽  
Author(s):  
Haoyang Yu ◽  
Alyxandra Thiessen ◽  
Md Asjad Hossain ◽  
Marc Julian Kloberg ◽  
Bernhard Rieger ◽  
...  

<div><div><div><p>Covalently bonded organic monolayers play important roles in defining the solution processability, ambient stability, and electronic properties of two-dimensional (2D) materials such as Ge nanosheets (GeNSs); they also hold promise of providing avenues for the fabrication of future generation electronic and optical devices. Functionalization of GeNS normally involves surface moieties linked through covalent Ge−C bonds. In the present contribution we extend the scope of surface linkages to include Si−Ge bonding and present the first demonstration of heteronuclear dehydrocoupling of organosilanes to hydride-terminated GeNSs obtained from the deintercalation and exfoliation of CaGe2. We further exploit this new surface reactivity and demonstrated the preparation of directly bonded silicon quantum dot-Ge nanosheet hybrids.</p></div></div></div>


Author(s):  
S.-S. Lee ◽  
J.-S. Seo ◽  
N.-S. Cho ◽  
S. Daniel

Abstract Both photo- and thermal emission analysis techniques are used from the backside of the die colocate defect sites. The technique is important in that process and package technologies have made front-side analysis difficult or impossible. Several test cases are documented. Intensity attenuation through the bulk of the silicon does not compromise the usefulness of the technique in most cases.


2020 ◽  
Vol 20 (11) ◽  
pp. 1001-1016
Author(s):  
Sandra Ramírez-Rave ◽  
María Josefa Bernad-Bernad ◽  
Jesús Gracia-Mora ◽  
Anatoly K. Yatsimirsky

Hybrid materials based on Mesoporous Silica Nanoparticles (MSN) have attracted plentiful attention due to the versatility of their chemistry, and the field of Drug Delivery Systems (DDS) is not an exception. MSN present desirable biocompatibility, high surface area values, and a well-studied surface reactivity for tailoring a vast diversity of chemical moieties. Particularly important for DDS applications is the use of external stimuli for drug release. In this context, light is an exceptional alternative due to its high degree of spatiotemporal precision and non-invasive character, and a large number of promising DDS based on photoswitchable properties of azobenzenes have been recently reported. This review covers the recent advances in design of DDS using light as an external stimulus mostly based on literature published within last years with an emphasis on usually overlooked underlying chemistry, photophysical properties, and supramolecular complexation of azobenzenes.


2020 ◽  
Vol 16 (2) ◽  
pp. 204-213 ◽  
Author(s):  
Melissa A. Vetten ◽  
Mary Gulumian

Background: Endotoxin-free engineered nanoparticle suspensions are imperative for their successful applications in the field of nanomedicine as well as in the investigations in their toxicity. Gold nanoparticles are known to interfere with various in vitro assays due to their optical properties and potential for surface reactivity. In vitro endotoxin testing assays are known to be susceptible to interference caused by the sample being tested. Objective: This study aimed to identify a preferred assay for the testing of endotoxin contamination in gold nanoparticle suspensions. Methods: The interference by gold nanoparticles on three assays namely, the commonly used limulus amebocyte lysate chromogenic assay, the limulus amebocyte lysate gel-clot method, and the less common recombinant Factor C (rFC) assay, was tested. Results: Possible interference could be observed with all three assays. The interference with the absorbance- based chromogenic assay could not be overcome by dilution; whilst the qualitative nature of the gel-clot assay excluded the possibility of distinguishing between a false positive result due to enhancement of the sensitivity of the assay, and genuine endotoxin contamination. However, interference with the rFC assay was easily overcome through dilution. Conclusion: The rFC assay is recommended as an option for endotoxin contamination detection in gold nanoparticle suspensions.


2021 ◽  
Author(s):  
Manasi Doshi ◽  
Eric Paul Fahrenthold

Explosives and hazardous gas sensing using carbon nanotube (CNT) based sensors has been a focus of considerable experimental research. The simplest sensors have employed a chemiresistive sensing mechanism, and rely...


Sign in / Sign up

Export Citation Format

Share Document