Hybrid POSS Lecture 12

Class 2B: Inorganic and organic polymeric phases are mixed and

form covalent interactions

tin oxides and polymers with carboxylate groups.

But not a lot in the literature

Cross-linking through fullerenes

Used to purify C60.Did not look at mechanical propertiesRequires solvent to prepare

Cross-linking through fullerenes: my new idea

Liquid polymer- no solvent needed

Modified organic polymers: Trialkoxysilyl side groups

Polybutadiene with side groups

Grafted triethoxysilyl groups on polyethylene for moisture crosslinking

May also be applied with vinyltriethoxysilane and RF plasma

Excellent for moisture curing polyethylene

Macromolecules, 2004, 37 (10), pp 3532–3535

Anisotropic Micellar Nanoobjects from Reactive Liquid Crystalline Rod−Coil Diblock Copolymers

Modified organic polymers: Trialkoxysilyl end groups

Macromolecules 1992,25, 5742-5751

Hydrogenated polybutadiene telechelics with triethoxysilyl groups

Triethoxysilyl terminated polysulfone

Macromolecules 1991;24:3449–50.

Anneal > 200 °CTiO2 sol in THF

Tailorable refractive index1.6 < n < 1.8

Chem. Mater., 2009, 21 (3), pp 463–467

Drug delivery hybrid gel

Polyethylene glycolTreithoxysilyl group on each endUrea linkage

Drug delivery hybrid gel

Chem. Mater., 2009, 21 (3), pp 463–467

PEO Bridged polysilsesquioxane hybrids

• Bacteriocide Ag-silsesquioxane coatings Biomacromolecules, 2007, 8 (4), pp 1246–1254

• Polymer electrolytes Solid State Ionics, 1999, 116, 197–209

• Coatings for steel. Adv. Technology 2008, 27, 117-126

• Electrochemically deposited coatings for stints New J. Chem., 2009, 33, 1596-1604

• Luminescent materials J. Non-Crystal Solids 2006, 352, 2292–2295 & Chem. Mater., 2004, 16 (13), pp 2530–2543

• Contolled druge release Chem. Mater., 2009, 21 (3), pp 463–467

PEO bridged polysilsesquioxanes

for polymer electrolytes

New J. Chem., 2012, 36, 1218-1223

Templating of structures and pores in hybrids, inorganics and organics

In templating, you build a material around some molecule, macromolecules or liquid crystal

Opals were used as templates for inverse opals and photonic solids (described in an earlier lecture).First we will see polymers phase segregation during sol-gel polymerization generating bone linke structures in hybrids.

Then we will look at liquid crystalline surfactant or block copolymer templates

Polymer phase separation templation of macropores

J. Mater. Chem., 2009, 19, 7716-7720

Using other phase separations to control how particles aggregate

Surfactants

Polymers

Block copolymers

Hydrophilic Phase

Hydrophobic PhaseMonomers are often dissolve in this phase

Hydrolyzed monomers and polymers are often dissolve in this phase

Polymers are not very soluble in each other and will phase separate like oil and water

Larger structures

Smallerstructures

Cited over 10,200 times

The Mobil patent was duplicating something already in the literatureSomebody did not do a careful literature search!!!!!!

Traditional ionic surfactants used in mesoporous materials templation

Traditional non-ionic surfactants used in mesoporous materials templation

Phase separation: surfactants

Pore models of mesostructures with symmetries of (A) p6mm, (B) Ia3Cd, (C) Pm3Cn, (D) Im3Cm, (E) Fd3Cm, and (F) Fm3Cm.

MCM-41

FDU-12SBA-16

SBA-1

FDU-2

MCM-48

Adv. Mater 1999, Brinker

First model for surfactant templating: assumes liquid crystal occupies entire solution

A few nanometers in diameter

Published in: Avelino Corma; Chem. Rev. 1997, 97, 2373-2420.

1) n-Hexadecyltrimethylammonium bromide (2.5 g, 0.007 mol) was dissolved in deionized water (50 g)2) To this surfactant solution, 13.2 g of aqueous ammonia (32 wt.%, 0.25 mol) and 60.0 g of absolute ethanol (EtOH, 1.3 mol) were added and the solution was stirred for 15 min (250 rpm).3) TEOS (4.7 g, 0.022 mol, freshly distilled) was added at one time resulting in a gel. 4) After stirring for 2 h the white precipitate was filtered and washed with 100 ml of deionized water and 100 ml of methanol. 5) After drying overnight at 363 K, the sample was heated to 823 K (rate:1 K min−1) in air and kept at that temperature for 5 h.

Synthesis of MCM-41 spheres

Microporous and Mesoporous Materials, 1999, 27, 207–216

Synthesis of MCM-41 silica spheres

Microporous and Mesoporous Materials, 1999, 27, 207–216

X-ray diffraction pattern of an MCM-41 sample prepared in heterogeneous medium with n-hexadecylpyridinium chloride as template.

Size of MCM 41 pores can be controlled by process conditions

TEM image of the honeycomb structure of MCM-41 and a schematic representation of the hexagonal shaped one-dimensional pores.

A close look at the structure shows that it is made of small amorphous silica particles

Just like the silica in living sponges> 1 nm in size

X-Ray Diffraction (XRD)

These materials show peaks at very small angles = larger structures than are typical in crystalline materials

formation mechanism of the templated nanoporous silicas

New mechanism has individual surfactant molecules and micelles playing a role in developing architecture

.Chem. Rev., 2002, 102 (11), pp 4093–4138

Zeolite: silicalite

Structure of SBA-1 or SBA-6 observed as an electron density and described either in terms of a clathrate structure or as a surface enveloping the micellar templating agents Nature, 2000, 408, 449

Electron micrographs of SBA-1 and SBA-6 along [100]

What are some of these materials and what do they look like (SBA-Santa Barbara.

Plane-projection of CDF (a), respective TEM image fragment (b) and its simulation (c).

Electronic density maps and bicontinuous cubic structure of MCM-48

Chem. Mater., 1996, 8, 1141

HREM images of CMK-4 along the three zone axes [100], [110] and [111] together with a representation of the carbonaceous surface.

J. Phys. Chem. B, 2002, 106, 1256

Chem. Rev., 2011, 111 (2), pp 765–789

How organic templates can control porosity of materials

Liquid crystal forms then monomer enters and reacts

Monomer starts reacting and interacting with surfactant as the liquid crystal forms

Making Hybrid Materials: Class 2C(Templating) Shown here with block copolymer

Tools for hierarchical materials structures

Phil. Trans. R. Soc. A 28 April 2009 vol. 367 no. 1893 1587-1605

Other challenges

• Ladder polysilsesquioxanes = super strong materials

• Pure polyhedral analogs the size of C60

• Fundamentals of particle formation and connectivity at nm length scale

• Mechanochemical direction of materials-like exercising developing muscles

Good-bye

Thank you

Good Luck

I will be here until November 23& should be back this summer