Sol–gel synthesis of transition-metal ion conjugated alumina-rich mullite nanocomposites with potential mechanical, dielectric and photoluminescence properties

RSC Advances ◽  
2015 ◽  
Vol 5 (126) ◽  
pp. 104299-104313 ◽  
Author(s):  
Arpan Kool ◽  
Pradip Thakur ◽  
Biswajoy Bagchi ◽  
Nur Amin Hoque ◽  
Somtirtha Banerjee ◽  
...  

Mechanical, dielectric and photoluminescence properties of transition-metal ions doped mullite nanocomposite synthesized via alkoxide hydrolysis.

2011 ◽  
Vol 233-235 ◽  
pp. 2219-2222 ◽  
Author(s):  
Xue Chun Zhong ◽  
Zhan Chang Pan ◽  
Zhi Gang Wei ◽  
Shu Guang Xie ◽  
Zhen Jun Cheng ◽  
...  

In this paper, TiO2crystallines doped with transition metal ions have been prepared by sol-gel method. The UV-visible spectra indicated that the doping with transition metal ions (especially Cu2+, Mn2+and Cr3+ions) could effectively improve the absorption of TiO2crystals in the visible-light range. The XRD results showed that the doping does not affect the anatase phase of TiO2. The band structure and the UV-vis absorption spectrum of Mn2+ions doped-TiO2were also calculated by DFT (density function theory) method, which indicated that the doping with transition metal ion could make the band gap of TiO2smaller and a red shift in optical absorption.


2021 ◽  
Author(s):  
Xuan Lin ◽  
Yanli Yang ◽  
Yanmin Song ◽  
Shuai Li ◽  
Xuan Zhang ◽  
...  

The structural instability of inactivated foot-and-mouth disease virus (FMDV) hinders the development of vaccine industry. Here we found that some transition metal ions like Cu2+ and Ni2+ could specifically bind to FMDV capsids at capacities about 7089 and 3448 metal ions per capsid, respectively. These values are about 33- and 16-folds of the binding capacity of non-transition metal ion Ca2+ (about 214 per capsid). Further thermodynamic studies indicated that all these three metal ions bound to the capsids in spontaneous enthalpy driving manners (ΔG<0, ΔH<0, ΔS<0), and the Cu2+ binding had the highest affinity. The binding of Cu2+ and Ni2+ could enhance both the thermostability and acid-resistant stability of capsids, while the binding of Ca2+ was helpful only to the thermostability of the capsids. Animal experiments showed that the immunization of FMDV bound with Cu2+ induced the highest specific antibody titers in mice. Coincidently, the FMDV bound with Cu2+ exhibited significantly enhanced affinities to integrin β6 and heparin sulfate, both of which are important cell surface receptors for FMDV attaching. Finally, the specific interaction between capsids and Cu2+ or Ni2+ was applied to direct purification of FMDV from crude cell culture feedstock by the immobilized metal affinity chromatography. Based on our new findings and structural analysis of the FMDV capsid, a “transition metal ion bridges” mechanism that describes linkage between adjacent histidine and other amino acids at the inter-pentameric interface of the capsids by transition metal ions coordination action was proposed to explain their stabilizing effect imposed on the capsid. IMPORTANCE How to stabilize the inactivated FMDV without affecting virus infectivity and immunogenicity is a big challenge in vaccine industry. The electrostatic repulsion induced by protonation of a large amount of histidine residues at the inter-pentameric interface of viral capsids is one of the major mechanisms causing the dissociation of capsids. In the present work, this structural disadvantage inspired us to stabilize the capsids through coordinating transition metal ions with the adjacent histidine residues in FMDV capsid, instead of removing or substituting them. This approach was proved effective to enhance not only the stability of FMDV, but also enhance the specific antibody responses; thus, providing a new guideline for designing an easy-to-use strategy suitable for large-scale production of FMDV vaccine antigen.


2017 ◽  
Vol 41 (19) ◽  
pp. 11190-11200 ◽  
Author(s):  
Dijo Prasannan ◽  
Chellaiah Arunkumar

Recognition of transition metal ions and bioaccumulation in B. subtilis and B. cereus were examined using pentafluorophenyl dipyrrin probe.


RSC Advances ◽  
2017 ◽  
Vol 7 (42) ◽  
pp. 26411-26419 ◽  
Author(s):  
Hongli Wen ◽  
Bing-Ming Cheng ◽  
Peter A. Tanner

Charge transfer emission from transition metal ions in glasses and identification of their oxidation states.


2014 ◽  
Vol 43 (23) ◽  
pp. 8805-8813 ◽  
Author(s):  
Xin-Xin Xu ◽  
Zhong-Ping Cui ◽  
Xin Gao ◽  
Xiao-Xia Liu

To enhance the photocatalytic activity of CP1, TMI/CP1 were synthesized and their photocatalytic activities were studied.


1988 ◽  
Vol 58 (4) ◽  
pp. 198-210 ◽  
Author(s):  
James W. Rucker ◽  
David M. Cates

Peracetic acid can be catalyzed to bleach cotton fibers at temperatures as low as 30°C by incorporating 2,2î-bipyridine in the bleach solution. Treatment of the fibers with HCl prior to bleaching reduces bleaching effectiveness by removing trace transition metal ions from the fibers. Sorption of individual ions (Cr+3 Mn+2, Fe+2, Fe+3 Co+2, Ni+2, Cu+2, and Zn+2) by HCl treated cotton fibers prior to bleaching indicates that the ferrous ion produces the greatest catalytic effect, and it is only effective when the metal ion is in the fiber as opposed to in solution. Ferrous ions in the fibers sorb 2,2î-bipyridine from solution to form the tris-2,2î-bipyridine ferrous ion complex that is associated with the fibers, and it is the trischelate associated with the fibers that catalyzes bleaching. The effects of pH, temperature, and concentrations of 2,2î-bipyridine, sodium lauryl sulfate, and transition metal ions (in the fibers and in solution) on bleaching effectiveness and peracetic acid decomposition have been studied, and a bleaching mechanism is proposed.


Sign in / Sign up

Export Citation Format

Share Document