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Third Workshop on Future Directions of Solid State Chemistry
The Status of Solid State Chemistry and its Impact in the Physical Sciences
Northwestern UniversityMay 18 - 20, 2006
OrganizersMercouri G Kanatzidis
Kenneth Poeppelmeier
Subpanel 8The place of solid state chemistry within other physical disciplines
Peter Burns (Purdue) Julia Chan (LSU)
Anne Meyer (SUNY Buffalo)Chris Murray (IBM)
Art Ramirez (Lucent)Michael D. Ward (NYU, chair)
Lian Yu (U Wisconsin)
• Assess impact of SSC on the physical sciences through continuing advances and the many ways of interacting across disciplinary boundaries
• Assess how to make the NSF and the scientific community more aware of this impact
• Assess the links between SSC and “hybrid materials”, which are inherently interdisciplinary
• Assess how SSC impacts other fields with respect to understanding and predicting the properties of materials, and stimulating the discovery of new materials
• Premise: greatest opportunities often exist at the interdisciplinary boundaries
Some stated objectives for 2006 SSC workshop
NSF-supported interdisciplinary initiatives
• Materials Research Science and Engineering Centers (MRSEC)
• Engineering Research Centers (ERC)
• Nano initiative (NSECs, NIRTs)
• Focused research groups (FRGs)
• Integrative Graduate Education and Research Traineeship Program (IGERT)
• Industry/University Cooperative Research Centers Program (I/UCRC)
• Nanoscale Interdisciplinary Research Teams (NIRTs)
• Others….
Global questions
• How much SSC is embedded within interdisciplinary NSF programs?
• What about other agencies (DOE, DOD, etc.)?
• How is solid state chemistry currently impacting other disciplines? Is the impact growing? How do we measure this? How do we increase the awareness of this impact?
• What is the impact of solid state chemistry in the context of societal needs that can only be addressed through connections to other disciplines?
• What are the future growth opportunities for SSC in other disciplines?
• How do investigators in different disciplines connect, particularly those that extend beyond the physical sciences?
• What are the best mechanisms for promoting these ventures?
• Are the current funding mechanisms sufficient in terms of efficacy and financial support?
• Should new mechanisms be considered?
The role of SSC in other disciplines
Today’s examples•Geology•Biology•Medicine/Disease•Pharmacy•Physics•Energy•Organic devices•Information technology
Missing, but not to be ignored•Ordered mesoporous solids and templated synthesis•Soft Materials•Hierarchical core-shell structures•Molecular materials
- metal-organic and hydrogen-bonded networks- organic conductors and magnetic materials
•Nanomaterials- magnetic materials- quantum dots
Solid-state chemistry and geology
• Minerals: Raw materials for technology
• Critical technological, social, and political issues (e.g., water, oil)
• Solid state chemistry and environment: transport of contaminants by groundwater, radionuclide release
• Strong overlap with other fields: glasses, zeolites, cements
• Methodologies of petrologists: wider application in solid state chemistry
• Geology involves nanoscale processes: physics and chemistry molecular level concepts
• Mineralogists often expert crystallographers familiar with complex inorganic structures
Chernobyl Lava
Studtite and Metastudtite
Burns & Hughes (2003): Am. Mineral.
c
[(UO2)(O2)(H2O)2](H2O)2
An actinyl peroxide with linked polyhedra
Structural Hierarchy of Uranyl Phases
Polymerization of Polyhedra of Higher Bond-Valence
Frequency as of spring, 2005: Total (Minerals)
Relevant to radionuclide release in geologic nuclear waste repositories
(including parasitic radionuclides: neptunium)
IsolatedClusters
Chains Sheets Frameworks
35 7 5343 (6) 57 (9) 204 (70) 56 (4)
Burns (2005): Can. Mineral.
Solid state chemistry and biology
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Skeleton of hexactinellid sponge Euplectella sp.
Aizenberg, et al., Science 2005,309, 275 - 278
• Mechanically robust glass structure with unusual periodic features
• Strength attributed to hierarchical structures across large range of length scales
• Impact on biology, mechanical engineering, nanoscience…
• Templating phenomena: single crystal magnetic nanorods; structural scaffolds based on composites (calcium carbonate + protein)
Solid-state chemistry and biology (clinical)
• Bioactive glasses: SiO2–CaO–P2O5–MO (M= Na, Mg, etc.)
• Bone-forming activity associated with:- composition- porosity- specific surface area- crystallinity- particle size
• Slow induction period for crystalline apatite formation
• Lack of plasticity limits practical applications
• Requirements for bioactive glass:
- can be injected and molded into irregularly shaped defects in bones and teeth
- hardens rapidly
- promotes rapid formation of biocompatible HA layers that promote cellular processes
Solid-state chemistry: new biocompatible cements
• Plastic but rapid setting cement from mesoporous bioactive glass in ammonium phosphate solution
• Fully set cement retains geometrical shape and mechanical strength
• Induces accelerated in vitro calcium-deficient hydroxyapatite nanocrystals (Ca10(PO4)6(OH)2) during setting (30 minutes)
• Mesoporosity + surface composition + regulation of Ca2+ = superior in vivo bone-forming?
extruded, 10 min.
molded, 10 min.
Stucky, et al., Adv. Mater. 2006, 18, 1038
Solid-state chemistry and bioactive surfaces
Human osteoblast cells on Si-3 after 1.5 hours: actin filaments (red); focal adhesions (green)
• Solid monolayer films with reactive tails
• AFM: 1.8 nm thick, roughness = 0.4 nm
• Adhesion of osteoblasts, fibroblasts, tumor cell lines.
• Also two different Chinese hamster ovary (CHO) cell lines with RGD-binding 51 and v3 integrins
Generic surfaces with hydrolytic stability and physiologic activitySchwartz, et al., Langmuir, 2004, 20, 5501
CHO4 adhered specifically to an anti-4-integrin antibody
CHO5 cells adhered specifically to an anti-5-integrin antibody
Generic IgG antibody surfaces with immobilized monoclonal antibodies bind specific cell lines
Kidney stone formation
Therapies for stone prevention more desirable
Need to understand critical events at the fundamental level
Stages of stone formation
• Calcium oxalate monohydrate (COM) aggregates and adheres to epithelial cells
• Calcium oxalate dihydrate (COD) “protective”
• Crystal aggregation/attachment influenced by urinary macromolecules
Adhesion force measurements: COD vs. COM
Sheng, et al., Proc. Nat. Acad. Sci. 2005, 102, 267 Sheng, et al., J. Amer. Soc. Nephrol. 2005, 16, 1904
COD and COM crystal surfaces
0.0542 Ca2+/Å2
0.0429 Ca2+/Å2
0.0333 Ca2+/Å2
0.0439 Ca2+/Å2
0.0225 Ca2+/Å2
COD vs. COM: pathological activity
• COM (100) and COD (101) most prominent faces in vivo
• Aggregation and attachment critical processes
www.herringlab.com
COM (100) stacks in a stone COM (100)
Non-specific binding
COD (101)
• Metals, metal alloys, ceramics, non-absorbable polymers: the "stuff" of devices & implants
• The role of SSC in tissue engineering needs to be better defined
• Complex interactions with proteins and cells need to be defined at a fundamental level
• Are the effects of nanosized features on interactions due to size alone…
• Or can biology “sense” different crystal structures (e.g. atomic spacing, surface structure and composition)
• What tools are needed to explore and predict these responses?
• Increased support for biologically oriented approaches in solid-state materials?
• Scientists, engineers, and clinicians must bridge a “culture” gap for interdisciplinary interactions
• NSF vs. NIH (or (NSF + NIH)?
Solid-state chemistry and biology (clinical)
Solid state chemistry and pharmaceuticals
• Solid state properties of pharmaceuticals crucial for bioavailability
• Polymorphism difficult to control; important for FDA certification and patent protection
• Solid state transformations impact stability (shelf life)
• “Disappearing polymorphs”
• Challenge: Selective crystallization of polymorphs and enantiomorphs
• $100 billion impact
• Other specialty chemicals
Pharmaceutical polymorphism
N
SO
O
HN
Ph
OHPh
NH
OHN
O
N N
S
Chemburkar, et al., Org Proc. Res. Dev. 2000, 4, 413.Bauer, et al., Pharm. Res. 2001, 18, 859.Law, et al., J. Pharm. Sci. 2001, 90, 1015.Morrisette, et al., PNAS 2003, 100, 2180.
Ritonavir (Norvir, Abbot Labs)
• 1996: introduced as protease inhibitor• Not bioavailable as solid form• Oral liquid or semi-solid capsules• 1998: Failed dissolution test• Conformational polymorph• Form I undersaturated• Form II 400% supersaturated• Cold storage not possible• Reformulated as Form II ($$$)• Now 5 polymorphs total• Regulating crystal growth imperative!
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Solid state chemistry and pharmaceuticals
Spherulites crystallized from D-mannitol melt.
Yu, J. Am. Chem. Soc. 2003, 125, 6380
HO
HO OH
HO OH
HO
mannitol
: P212121
P21
• Methods for reliable prediction of polymorphs needed
• High-throughput screening
• Amorphous phases emerging
• Crystallization one of the largest unit operations
• Need to elucidate crystallization processes at the fundamental level
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