Soft Nanoscience Letters, 2014, 4, 6-14
Published Online January 2014 (http://www.scirp.org/journal/snl )
http://dx.doi.org/10.4236/snl.2014.41002
OPEN ACCESS SNL
Polymeric Liquid Templating of Hierarchical Porous Films
by Nanofibrillar Alginic Acid Assemblies
Thai-Hoa Tran
1
, Sy-Thang Ho
2
, Thanh-Dinh Nguyen
3*
1
Department of Chemistry, College of Sciences, Hue University, Hue, Vietnam;
2
Department of Chemistry, Dong Thap University,
Dong Thap, Vietnam;
3
Department of Chemical Engineering, Laval University, Quebec, Canada.
Email:
*
thanh-dinh.nguyen.1@ulaval.ca
Received July 9
th
, 2013; revised August 9
th
, 2013; accepted August 16
th
, 2013
Copyright © 2014 Thai-Hoa Tran et al. 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. In accor-
dance of the Creative Commons Attribution License all Copyrights © 2014 are reserved for SCIRP and the owner of the intellectual
property Thai-Hoa Tran et al. All Copyright © 2014 are guarded by law and by SCIRP as a guardian.
ABSTRACT
Hierarchical phases of the biomaterials can be used as template to transfer their intricate organization into bio-
mimic inorganic solids. Herein, hierarchical mesoporous silica films with aligned pores have been templated by
nanofibrillar alginic acid. An aqueous suspension of the alginic acid nanofibers was prepared by treating the
brown seaweeds with sodium carbonate solution and subsequent precipitation in dilute hydrochloric acid. The
alginic acid nanofibers of the organization into a hierarchical aligned phase in an acetic acid-sodium acetate
buffer were used to template silica-alginic acid composite films by evaporation-induced self-assembly of alkoxy-
silane with nanofibrillar alginic acid. Calcination of the alginic acid template afforded hierarchical mesoporous
silica glasses. Carbonization of the silica-alginic acid composites and subsequent etching the silica recovered me-
soporous carbon supercapacitors.
KEYWORDS
Nanofibrillar Alginic Acid; Hierarchial Organization; Mesoporosity; Silica Films; Carbon Supercapacitors
1. Introduction
Sophisticated biomaterials are normally fabricated in na-
ture by oriented hierarchical organization of simple na-
noscale elements [1,2]. Polymeric liquid templating of-
fers a biomimetic approach to synthesizing materials
with intricate organization that mimic the sophisticated
structures found in nature [3,4] The use of the polymeric
liquid templating could allow to control the order of the
morphology and structural orientation of such materials
[5-7]. Mesoporous silica materials synthesized via poly-
meric liquid templating with a surfactant have been the
subject of widespread research in materials chemistry
[8,9]. The mesochannel structured materials have unique
optical properties, giving them potential opportunities in
applications as optical elements [10], catalyst supports
[11], adsorbents [12], and solar cells [13].
Hierarchical phases of the biomacromolecules of po-
lysaccharides, collagen, proteins, and DNA can be use as
biotemplates to prepare solid-state materials [1,14]. Al-
ginic acid, a linear copolymer consisting mainly of resi-
dues of β-1,4-linked D-mannuronic acid and α-1, 4-linked
L-glucuronic acid, is the main structural component of
the cell walls of brown seaweeds [15,16]. Alginic acid,
which is found in the brown seaweeds, is an abundant
polysaccharide in the ocean. Alginic acid extracted from
the seaweeds could be used as a renewable resource for
tissue engineering as delivery vehicle for drugs and
gelling agent for food products.
Alginic acid fibers are typically prepared by treating
the brown seaweeds with alkaline conditions and subse-
quent precipitation in dilute hydrochloric acid [16]. Aque-
ous suspensions of the alginic acid could be stabilized in
a buffer solution. The exposed carboxylic acid groups on
the polymeric chains could be partially deprotonated to
provide negative surface charge, which leads to repulsive
forces between fibers. The extent of the deprotonation
changes the surface charge density and could affect the
critical concentration for the formation of the hierarchical
*
Corresponding author.