• JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
  • JoomlaWorks Simple Image Rotator
 
  Bookmark and Share
 
 
Doctoral Thesis
DOI
https://doi.org/10.11606/T.43.2018.tde-20072018-102259
Document
Author
Full name
Alysson Ferreira Morais
Institute/School/College
Knowledge Area
Date of Defense
Published
São Paulo, 2018
Supervisor
Committee
Mustafa, Danilo (President)
Constantino, Vera Regina Leopoldo
Lourenço, Ana Valéria Santos de
Santos, Antonio Domingues dos
Wiederhecker, Gustavo Silva
Title in Portuguese
Preparação e estudo de nanotubos luminescentes de hidróxidos duplos lamelares (LDH) contendo íons terras raras
Keywords in Portuguese
hidróxidos duplos lamelares
luminescência
materiais porosos
nanomateriais
nanotubos
Abstract in Portuguese
Hidróxidos duplos lamelares (LDHs) são uma classe materiais lamelares com fórmula química [M_(1-x)^II M_x^III (OH)_2 ] [A^(n-)]_(x/n).yH_2 O (onde M^II e M^III são metais di e trivalentes, respectivamente) formados pelo empilhamento de camadas positivamente carregadas de hidróxidos metálicos intercaladas por espécies aniônicas A^(n-). Este trabalho descreve uma estratégia inédita para a produção de nanotubos de LDHs autossuportados (Ø 20 nm e comprimentos >= 100 nm) através da coprecipitação de Zn^(2+), Al^(3+) e Eu^(3+) em pH controlado e sua auto-organização sobre micelas cilíndricas do surfactante Plurônico® P-123. A subsequente extração destes agentes estruturantes através de lavagem com metanol resulta em uma rede de nanotubos cilíndricos, ocos e interconectados, formados pela deposição de multicamadas de hidróxidos duplos intercalados pela molécula sensibilizadora ácido benzeno-1,3,5-tricarboxílico (ácido trimésico, BTC). A combinação de Eu3+ nas camadas de hidróxidos e BTC no meio interlamelar resulta em nanotubos com propriedades luminescentes, demonstrando de maneira notável como modificações químicas e morfológicas nos LDHs podem levar ao remodelamento das suas propriedades físico-químicas e consequentemente direcionar suas aplicações de maneira desejável.
Title in English
Preparation and study of layered double hydroxide (LDH) nanotubes containing rare earth ions
Keywords in English
layered double hydroxides
luminescence
nanomaterials
nanotubes
porous materials
Abstract in English
Layered double hydroxides are a class of lamellar compounds with chemical formula [M_(1-x)^II M_x^III (OH)_2 ] [A^(n-)]_(x/n).yH_2 O (with M^II and M^III being di and trivalent metals, respectively) that are formed by the stacking of positively charged mixed-valence metal hydroxide sheets intercalated by anionic species A^(n-). This work describes a new strategy for the synthesis of self-supporting mesoporous LDH nanotubes (Ø 20 nm and length >= 100 nm) by coprecipitation of Zn^(2+), Al^(3+) and Eu^(3+) around non-ionic worm-like micelles of Pluronic® P-123 in controlled pH. Subsequent extraction of the structure-directing agent with methanol results in a network of interconnected, well-defined, multi-walled and hollow cylindrical LDH nanotubes intercalated by the sensitizing ligand BTC (1,3,5-benzenetricarboxilate). The combination of Eu^(3+) in the hydroxide layers and BTC in the interlayers results in nanotubes with luminescence properties in a notable demonstration on how chemical and morphological changes in LDHs can lead to materials with tuned physico chemical properties that can be tailored towards a range of applications.
 
WARNING - Viewing this document is conditioned on your acceptance of the following terms of use:
This document is only for private use for research and teaching activities. Reproduction for commercial use is forbidden. This rights cover the whole data about this document as well as its contents. Any uses or copies of this document in whole or in part must include the author's name.
TeseAlysson.pdf (4.81 Mbytes)
Publishing Date
2018-07-20
 
WARNING: Learn what derived works are clicking here.
All rights of the thesis/dissertation are from the authors
CeTI-SC/STI
Digital Library of Theses and Dissertations of USP. Copyright © 2001-2024. All rights reserved.