Ice-Templated Materials: Sophisticated Structures Exhibiting Enhanced Functionalities Obtained after Unidirectional Freezing and Ice-Segregation-Induced Self-Assembly†

2008 ◽  
Vol 20 (3) ◽  
pp. 634-648 ◽  
Author(s):  
María C. Gutiérrez ◽  
María L. Ferrer ◽  
Francisco del Monte
Keyword(s):  
Self Assembly ◽  
Unidirectional Freezing ◽  
Templated Materials ◽  
Ice Segregation

Current Understanding of Formation Mechanisms in Surfactant-Templated Materials

2005 ◽  
Vol 58 (9) ◽  
pp. 627 ◽  
Author(s):  
Karen J. Edler
Keyword(s):  
Self Assembly ◽  
High Surface ◽  
High Surface Area ◽  
Formation Mechanisms ◽  
Surfactant Micelle ◽  
Surfactant Micelles ◽  
Molecular Separation ◽  
Inorganic Species ◽  
Templated Materials ◽  
High Surface Area Materials

Surfactant-templated materials are created through self-assembly in solutions containing both surfactant micelles and an inorganic species. The resulting materials are composites containing an organized surfactant micelle array encapsulated in the inorganic material. Removal of the surfactants generates nanoscale pores which replicate the highly organized micelle phase, producing high surface area materials with uniform pores that have applications in catalysis, molecular separation, encapsulation for sensors and slow release, and thin films for optoelectronics and photoelectrochemical devices. This review looks at recent work aimed at understanding how these materials self-assemble from dilute surfactant solutions to form intricate nanoscale configurations, which also often show complex and highly ordered structures on longer length scales.

Preparation of crystal TiO2 foam with micron channels and mesopores by a freeze-casting method without additives and unidirectional freezing

CrystEngComm ◽  
2018 ◽  
Vol 20 (38) ◽  
pp. 5782-5789 ◽  
Author(s):  
Yingchao Yang ◽  
Qing Xie ◽  
Somnath Mukherjee ◽  
Yan Zheng ◽  
Xiangyang Yan ◽  
...  
Keyword(s):  
Self Assembly ◽  
Freeze Casting ◽  
Casting Method ◽  
Unidirectional Freezing ◽  
Novel Strategy

A novel strategy facilitated by self-assembly of a ligand to prepare crystal TiO2 foam with micron channels and mesopores.

TEM investigations of self-assembly through physical synthesis

1994 ◽  
Vol 52 ◽  
pp. 436-437
Author(s):  
S. Walker ◽  
E. Naranjo ◽  
S. Chiruvolu ◽  
J. Zasadzinski
Keyword(s):  
Self Assembly ◽  
Anionic Surfactants ◽  
Surfactant Solution ◽  
Ionic Species ◽  
Mesoporous Silicas ◽  
Surfactant Interactions ◽  
Component Systems ◽  
Physical Synthesis ◽  
Cationic And Anionic Surfactants ◽  
Templated Materials

A novel way of enlarging the realm of surfactant solution microstructure is the "physical synthesis" of new microstructures and surfactant-templated materials by mixing simple surfactants or surfactant and inorganic and ionic species. Mixing can often produce properties not possessed by any one species alone. As we have recently shown, mixtures of single-tailed cationic and anionic surfactants associate in solution to form a quasi-double-tailed catanionic surfactant that forms bilayers rather than the simple micelles each species would form on its own. Mixed surfactant systems apparently produce new microstructures by altering the intermolecular and interaggregate forces in ways impossible for single component systems. In addition to spontaneous vesicles, we have found other new microstructures including dilute lamellar and L3 phases depending on the details of the surfactant mixture. Surfactant interactions with ionic species also play an important role in the in synthesis of a new M41S family of mesoporous silicas, and are likely to be important in the templating of biominerals at interfaces. By understanding the molecular and chemical basis of these interactions, we can begin to tailor new microstructured and/or biomimetic materials by controlling surfactant aggregation and phase behavior through physical synthesis rather than through much more elaborate chemical synthesis.

Preparation and characterization of crosslinked chitosan/gelatin scaffolds by ice segregation induced self-assembly

2016 ◽  
Vol 141 ◽  
pp. 175-183 ◽  
Author(s):  
Marina Nieto-Suárez ◽  
M. Arturo López-Quintela ◽  
Massimo Lazzari
Keyword(s):  
Self Assembly ◽  
Crosslinked Chitosan ◽  
Ice Segregation

In vitro and in vivo polysaccharides assembly: ultrastructural and cytochemical study of growing plant cell wall components.

1978 ◽  
Vol 36 (2) ◽  
pp. 434-435
Author(s):  
D. Reis ◽  
B. Vian ◽  
J. C. Roland
Keyword(s):  
Cell Wall ◽  
Self Assembly ◽  
Plant Cell Wall ◽  
Higher Plants ◽  
Three Dimensional ◽  
Cytochemical Study ◽  
Wall Components

Wall morphogenesis in higher plants is a problem still open to controversy. Until now the possibility of a transmembrane control and the involvement of microtubules were mostly envisaged. Self-assembly processes have been observed in the case of walls of Chlamydomonas and bacteria. Spontaneous gelling interactions between xanthan and galactomannan from Ceratonia have been analyzed very recently. The present work provides indications that some processes of spontaneous aggregation could occur in higher plants during the formation and expansion of cell wall.Observations were performed on hypocotyl of mung bean (Phaseolus aureus) for which growth characteristics and wall composition have been previously defined.In situ, the walls of actively growing cells (primary walls) show an ordered three-dimensional organization (fig. 1). The wall is typically polylamellate with multifibrillar layers alternately transverse and longitudinal. Between these layers intermediate strata exist in which the orientation of microfibrils progressively rotates. Thus a progressive change in the morphogenetic activity occurs.

The Nature of Rapidly Extracted Phycocyanin from the Blue-Green Alga Plectonema Boryanum

1971 ◽  
Vol 29 ◽  
pp. 366-367
Author(s):  
M. Kessel ◽  
R. MacColl
Keyword(s):  
Self Assembly ◽  
Analytical Ultracentrifugation ◽  
Uranyl Acetate ◽  
The Self ◽  
Major Protein ◽  
Subunit Structure ◽  
Blue Green Alga ◽  
Thin Sections ◽  
Blue Green Algae ◽  
Cacodylate Buffer

The major protein of the blue-green algae is the biliprotein, C-phycocyanin (Amax = 620 nm), which is presumed to exist in the cell in the form of distinct aggregates called phycobilisomes. The self-assembly of C-phycocyanin from monomer to hexamer has been extensively studied, but the proposed next step in the assembly of a phycobilisome, the formation of 19s subunits, is completely unknown. We have used electron microscopy and analytical ultracentrifugation in combination with a method for rapid and gentle extraction of phycocyanin to study its subunit structure and assembly.To establish the existence of phycobilisomes, cells of P. boryanum in the log phase of growth, growing at a light intensity of 200 foot candles, were fixed in 2% glutaraldehyde in 0.1M cacodylate buffer, pH 7.0, for 3 hours at 4°C. The cells were post-fixed in 1% OsO4 in the same buffer overnight. Material was stained for 1 hour in uranyl acetate (1%), dehydrated and embedded in araldite and examined in thin sections.

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