1. Physics and Chemistry of Hybrid Organic-Inorganic Materials
Professor Douglas A. Loy
Visiting from the University of Arizona, United States

2. Syllabus Rm 410 Wednesdays 13:45-14:35, 14:40-15:30
Fridays 13:45-14:35, 14:40-15:30
Last day of class is June 11th
4 quizes
No final exam
Attendance and participation are graded

3. Course website For lecture slides and other info.
Not at HIT website, at Loy research website:
• Go to loy research group home page and select “courses” on menu at top.
• Class website: “Chemistry and Physics of Materials Harbin Institute of Technology ” is the second entry.
Direct url:

4. Lectures Lecture 1: Introduction to hybrids May 14
Lecture 2:Structures of Hybrids May 14
Lecture 3: Properties of Hybrids May 16
Lecture 4:Physics of phase separation & solutions May 16
Quiz May 21
Lecture 5:Naturally occurring hybrids May 21
Lecture 6: Making hybrids by physical mixing of materials May 23
Lecture 7:Polymerizing monomers to make hybrids May 23
Quiz May 28
Lecture 8: Polysilsesquioxanes May 28
Lecture 9: POSS systems May 30
Lecture 10: Bridged polysilsesquioxanes May 30
Quiz June 4
Lecture 11: Polymerizing organic monomers in inorganics materials June 4
Lecture 12: Polymerizing inorganic monomers in organic polymers June 6
Lecture 13: Surfactant templating materials June 6
Lecture 14 Frontiers in hybrids June 11
Quiz June 11

5. Example of quiz 1:
Quiz 1: Write your name, and ID number at top of page. Then write the answers to 1-10 in English.
What is a hybrid organic-inorganic material. Write a short definition.
2) Please, give an example of a hybrid organic-inorganic material?
3) Name three benefits of hybrid organic inorganic materials compared with organic polymers.
4) What analysis can you use to determine the thermal stability of a hybrid organic inorganic material in the laboratory?
5) How can you determine if a hybrid organic-inorganic material is crystalline or amorphous?  
6) How do you measure the strength of a hybrid organic inorganic material?
7) How can you tell if a hybrid organic inorganic material is one phase or two phases?
For a one phase solution to spontaneously separate into two phases, the free energy for separation must be?
9) What are the two types of phase separation mechanisms observed with hybrid organic inorganic systems? 
10) Explain what surface tension is and why small particles have higher surface energy than large particles.

6. What are hybrid organic-inorganic materials?
Mixtures of organic materials and inorganic materials
Hybrid organic inorganic materials are also called composite materials. An example of a composite material is an automobile tire.
Very important materials for 21st century economy

7. Lecture Objectives Identify hybrid organic inorganic materials
List benefits of using hybrids
Basic ways hybrids are put together
Understand what is meant by organic, inorganic, monomer, polymer and material.
Understand the size (length scales) in hybrids
know applications for hybrid materials
List hybrid organic-inorganics found in nature
The lecture objectives are meant to help you focus on key topics for the course. Find the answers to the above questions and you will be prepared for the quizes.

8. Identifying hybrids:Both organic and inorganic materials combined
IN tires the organic phases are the polyisprene rubber and nylon belts while the steel belts and carbon and silica filler are the inorganic phases. The length scales for the steel and nylon belts are very large, but that of the silica and carbon is on the 100 nanometer length scale.
Centimeter
Length scales
Steel, silica, & carbon – inorganic (strong)
Poly(isoprene) rubber – organic (flexible, adhesive, elastic)

9. Identifying hybrids: often have two phases
A close up look at the rubber in the tire shows about 30 wt% silica particles
The inorganic silica particles are nm in size.
The organic (polyisoprene rubber) is continuous
The carbon or silica filler is more opaque to the electrons in the transmission electron microscope, so it appears black.

10. Identifying hybrid organic materials
with Scanning electron microscopy
Inorganic particle
Organic polymer
Scanning electron microscopy uses electrons reflected from the surface for visualization just like a light microscope uses visible wavelengths of light. The silica particles are very white because they are accumulating electrons and becoming charged.
Features are often too small to see with the eye

11. Identifying Hybrid organic-inorganic materials
Hybrids may be a composite of multiple phases or a single hybrid phase.
multiphase composite – examine by SEM, AFM, TEM
Single phase material – elemental analysis
Quick method: burn the material and see if there is a residue. Organic burns, most inorganic will leave a residue

12. Benefits of Hybrid Organic Inorganic Materials
Stronger and stiffer than organics
Tougher and more flexible than inorganics
Less flammable than organics
When melted, more viscous (non-dripping)
Tailored optical properties (refractive index, transparency, scattering, absorptions)
High surface area porous materials
Hybrids may not have all of the beneficial characteristics. They generally have one or more if they are to be useful.

13. How are hybrids put together?
Physically mixing inorganic materials and organic polymers
Polymerizing an organic monomer in an inorganic material
Polymerizing an inorganic monomer in an organic material or polymer
Polymerizing a monomer with both organic and inorganic parts
This slide is about the synthesis of hybrids. The general strategies you would use to make them in a laboratory.

14. Organic monomers react by polymerizing into macromolecules
Equivalent to this shorthand structure
To introduce you to what monomers and polymers are, this slide shows you a styrene monomer that will combine with other styrene molecules in a chain reaction to create a macromolecule or polymer (called polystyrene).
As many as 20,000 monomers may be linked together to make a single macromolecule

15. Polymerization of inorganic or hybrid monomers to form materials
Hydrolysis:
Condensation:
Net Polymerization:
The same polymerization process can be used to prepare metal oxides or silica from monomeric precursors or hybrid materials directly from the polymerization of a hybrid monomer. These polymerization routes are just one of the four strategies for making hybrids mentioned earlier in the lecture.
Shown here for formation of a silsesquioxane

16. Hybrid from organic polymer and inorganic monomer
Solid Organic Polymer
Pre-made inorganic particles
dissolve or melt
solution or molten organic polymer
inorganic particles dispersed in solution or melted polymer
This is a physical mixing process where preformed particles are dispersed into a melted organic polymer or a polymer dissolved in a solvent. Then the melted polymer is cooled to afford a hybrid of continuous phase polymer with dispersed inorganic particles or the solvent is evaporated leaving a similar hybrid.
Cool melt below Tg or evaporate solvent

17. A hybrid might have silica nanoparticles mixed in with the polystyrene
The effect of having the particles dispersed in the polymer is to improved the thermal and mechanical propertiescompared to the polymer without the particles.
Such hybrids have higher glass transition temperatures, and are stronger, more flame resistant

18. Hybrid from organic polymer and inorganic monomer
Inorganic particle
Organic polymer
This is a hybrid in which the preformed silica particles were mixed with a ethanol solution of Nafion (an organic polymer electrolyte) before casting as a film.

19. Hybrid from organic polymer and inorganic monomer
Inorganic Monomer (liquid) & catalyst
Solid Organic Polymer
melt or dissolve
Mixture of Organic polymer and Inorganic Monomer & catalyst
Solution or emulsion
In this hybrid formation strategy, an inorganic monomer and reactants and catalyst is dissolved into the solid organic polymer where it polymerizes, phase separates to form an in-situ (in place) generated particle. This approach is less difficult to process than the physical mixing process mentioned on the previous two slides.
Monomer polymerizes & forms particles

20. Preparation by adding organic monomer into pores in inorganic material then polymerizing
organic Monomer (liquid) & catalyst
Porous Inorganic Material
Monomer must be soluble in polymer
Mixture of Organic Monomer & Inorganic Material
In this strategy, a liquid organic monomer is adsorbed into the pores in an inorganic material where it is polymerized to form an organic polymer. The holes in the inorganic material act to template the polymer and limits its growth.
Monomer polymerizes & fills pores with particles

21. Hybrid Monomer in solution
Polymerize monomer that has both organic and inorganic parts connected together with bonds
Hybrid Monomer in solution
Sol-gel polymerization
Hybrid organic-inorganic particles dispersed in solvent
In this strategy, the hybrid monomer with both organic and inorganic components in a small molecule is polymerized to afford a polymeric hybrid. As these are often highly crosslinked, the growing polymer phase separates out as particles and the particles, dispersed in the solution can either be cast to afford a film, collected and dried as a free flowing particulate solid or allowed to percolate and form a gel in which the solvent and the particles form interpenetrating phases. When the solvent is evpaorated, the result can be a material with a very high surface area.
Hybrid Coating
Hybrid Gel
Hybrid Particles

22. Structure of Hybrids atomic (Angstrom) macromolecular (nm’s) 1 micron
Structure of hybrids can be categorized at diffferent scales. At the very shortest length scale (measured by NMR and XRD) is the atomic structure. Longer length scale structure can be evaluated by smaller angle XRD and NMR, but also gel permeation chromatography or light scattering. Colloidal nanostructure is best characterized by electron microscopic techniques, surface area analyses and light scattering.
1 micron
Microstructure
or morphology (> 100 nm)
Colloidal or nanostructure (< 100 nm)

23. Length Scales
This slide is to give you perspective on the size scales described in these lectures.

24. Applications of hybrid materials
Coupling agents
For composites
Protective
coatings
Toughened
Composites
There are many applications for hybrid materials. Many, but not all, are based on organosilicon hybrids. Coupling agents used for tires are low Tg oligomers of organotrialkoxysilanes that are used to interconnect the silica filler now used in tires with the polyisoprene rubber. Protective coatings typically have a metal alkoxide component covalently linked to a polymerizable organic group that cures into a dense impervious coating to prevent water from artwork or construction, gases from passing through containers or OLED packaging, or aqueous corrosives to metal surfaces. Toughned composites are organic polymers that have been modified with inorganic groups that will crosslink the polymers and improve their toughness.
Tethers for
Bio-molecules
Chromatographic
Materials
(X-Bridge ®, Waters)
Photoresists for Lithography
Photographs courtesy of Gelest, Inc. and Waters Co.

25. Applications of hybrids
Impermeable hybrids to prevent loss of pressure
Strong, low density structural materials
Nylon-clay hybrids are now used commercially in truck bed materials, and to make tennis balls less permeable to air. They have also been used to help keep oxygen away from photovoltaic elements in solar panels.
Protective coatings on solar panels

26. More applications of hybrid materials
Low K Dielectrics
Adhesives
Sensor coatings
POSS have been widely used as low k dielectric materials for microelectronics. Adhesive based on POSS or other inorganic materials as filler and to improve abrassion resistance are widely available. A number of polysilsesquioxane have been used as coatings for surface accoustic wave guide sensors and electrochemcial sensors. A number of porous hybrids, particularly the bridged polysilsesquioxanes, and mesoprous surfactnan templated mateirals have been used as metal ion scavengers to remove toxic and potentially valuable metals from water. Optical coatings includes those designed to correct chromatic aberrations and to provide scratch resistance to optics. A number of hybrid encapsulants have been developed and are availble. Those with low tg components are suitable for wide temperature range fluctuations due to CTE mismatch.
Metal Scavenger
“resins”
Optical coatings
encapsulants
Plus ceramic precursors (e.g. SiC)

27. Hybrid Organic-Inorganic materials are common in nature
Animals
Organic phase is biopolymer
Nacre
Plants
phytolith
Argonite (CaCO3) plates as inorganic
with protein (polyamide) as organic
Hybrids are also commonly used by nature to improve strength of normally very weak materials.
Bone, teeth, spines in echinderms
Mussel shells, sponges, diatoms and corals are composed of hybrid organic-inorganic materials
Carbohydrates are the template and organic phase

28. Summary:
Hybrid materials are combinations of organic and inorganic components
the organic and inorganic parts can be in one phase or in separate phases.
Single phase hybrids are often made from hybrid monomers
Hybrids can have improved mechanical properties, thermal & chemical stability, and modified optical properties.
Hybrids have many applications