Next Article in Journal
Tuning Optical and Granulometric Properties of Gold Nanostructures Synthesized with the Aid of Different Types of Honeys for Microwave-Induced Hyperthermia
Previous Article in Journal
Preparation of [email protected]2 Nanofibers for Fruit Packaging Materials with Efficient Photocatalytic Degradation of Ethylene
Article Menu
Issue 6 (March-2) cover image

Export Article

Open AccessArticle

Porous Alumina Ceramics Obtained by Particles Self-Assembly Combing Freeze Drying Method

1
Key Laboratory of Aerospace Materials and Performance (Ministry of Education), School of Materials Science and Engineering, Beihang University, Beijing 100191, China
2
School of mechanical and chemical engineering, Wuzhou University, Wuzhou 543002, China
*
Author to whom correspondence should be addressed.
Materials 2019, 12(6), 897; https://doi.org/10.3390/ma12060897
Received: 3 February 2019 / Revised: 12 March 2019 / Accepted: 13 March 2019 / Published: 18 March 2019
(This article belongs to the Section Porous Materials)
  |  
PDF [2877 KB, uploaded 18 March 2019]
  |     |  

Abstract

An innovative approach for fabricating porous alumina ceramics is demonstrated in this paper. The distinguished feature is that the construction of the porous structure stems from the interaction between ceramic particles, which is a poorly explored area. By tailoring the Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy to the second minimum, the dilute ceramic slurry would be gelled by the weakly assembled particle network, and the assembled structure is conserved via a freeze drying strategy. The DLVO theoretical analyses revealed that the second minimum of interaction energy could be obtained when the counter-ion concentration in colloidal suspension is 1.5 × 10−2 mol/L. The properties of the as-assembled samples were compared with one produced by the conventional freeze drying method. Results showed that the self-assembly of alumina particles has a positive influence on micro structures. Unlike the laminar pores generated by the traditional freeze drying procedure, the assembled samples show homogeneously interconnected and hierarchical open pores which were stable even after a 24 h dwell time at 950 °C (open porosity is 79.19% for the slurry of vol 20% solid loading). Particularly, after sintering at 1550 °C for 2 h, open porosity (67.01%) of the assembled samples was significantly greater than that of their un-assembled counterparts (39.97%). Besides, the assembled sample shows a narrower pore size distribution and a relatively higher cumulative pore volume. View Full-Text
Keywords: porosity; alumina ceramics; self-assembly; freeze drying porosity; alumina ceramics; self-assembly; freeze drying
Figures

Graphical abstract

This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited (CC BY 4.0).
SciFeed

Share & Cite This Article

MDPI and ACS Style

Hu, S.; Feng, B.; Tang, X.; Zhang, Y. Porous Alumina Ceramics Obtained by Particles Self-Assembly Combing Freeze Drying Method. Materials 2019, 12, 897.

Show more citation formats Show less citations formats

Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Materials EISSN 1996-1944 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top