(pdf copies of selected papers available at above web site.)

The following listing of publications are organized in terms of general research areas where I have been active. These areas are discussed below the listing in Assessment of Publications.

Our research thrusts involve synthetic, morphological and thermodynamic basis of disordered materials. Polymers are an example of such disordered materials but the category includes low-dimensional inorganic structures such as those resulting from hydrolysis/condensation reactions and pyrolytic synthesis of metal oxides and organo-metalic oxides. Recently we have focused on application of nano-structured inorganic oxides as catalysts (pending NSF), tuned reinforcing fillers for polymers (pending NSF), UV absorbants (pending NSF/P&G), Knudsen super-insulators (Armstrong grant) and as precursors to wear resistant metal coatings (AFRL funded/DAGSI planned). The unifying feature of the disordered materials we are interested in is that they display structural scaling over a fairly wide range of size usually spanning at least two decades and usually on the nanometer scale. Such nano-structured materials can display special properties associated with their unique placement in size between molecular and macroscopic systems. These nano-structured materials can often be described using a fractal approach. Mass-fractal laws are a tool to describe and predict properties from otherwise complicated structures that defy simple description. The inorganic oxides shown to the left are an example from the work of Guo (MS 1997) where a high degree of control over such ramified structures has been obtained [F5]. Small-angle scattering is a natural technique for the description of fractals because the fractal dimension is quantitatively and directly observed with high accuracy in the scattering experiment. In a certain sense materials such as the inorganic oxides shown in the figure can be considered polymeric in that they are composed of chains of nano-structured "monomers" that in this case are silica/organic hybrid particles produced in a sol-gel reaction. In looking at disordered materials it is crucial to describe morphology over a wide range of size which necessitates the use of combined data sets from a series of scattering instruments ranging from light scattering to XRD and neutron powder diffraction techniques [I1-I2]. Additionally, analysis of such wide size range data involves the development of novel scattering theories [ST1-ST3] that can describe the many features of these complex disordered materials in terms of simple engineering properties.

We have taken advantage of these newly developed morphological tools and unique understanding of complex materials of this type to investigate the associations between polymeric and inorganic systems. From a fundamental perspective the application of fractal scaling laws to polymers [PB1, PB3-PB5] can solve some long pursued questions in polymer science such as anomalies in polymer blend behavior and conformational issues in elastomeric networks. From an applications perspective we have taken advantage of our unique expertise in the somewhat divergent fields of nano-structure oxides and plastics to develop novel filler materials for tires (collaboration with Goodyear) and to create new inexpensive UV absorbents based on nano-structured oxides for polymer applications (collaboration with P&G). Additionally, our understanding of disordered materials has been utilized in studies of the morphological scaling of non-woven fabrics [PB2] on a macroscopic scale. Each of the general research areas where we have been active are discussed in some detail below.

1) Sandia Efforts: Our work in nano-structured materials began with a post-doc at Sandia National Laboratories under Dale Schaefer, partly associated with John Curro and Al Hurd at Sandia and Doug Smith at UNM. Work at Sandia began with the polymer blends area, but quickly branched into nano-structured, semi-crystalline polymer foams discussed below (PAN and IPS foams) [C2-C4], amorphous polymer foams (RF system with the Livermore group) [F23], sol-gel ceramic based systems (Hurd's group at Sandia and Smith's group at UNM) [F21-F22, F25-F26, F32] as well as in situ based PDMS rubber/silica systems (with Dow Corning). A wide range of expertise existed at Sandia to deal with such morphologies, J. Brinker, J. Martin, A. Hurd, K. Keefer, D. W. Schaefer, D. Loy among others. Mass-fractal systems can be easily distinguished in log-log plots of scattering data by a weak power-law decay in intensity over decades of size which is limited at the large-scale (low-angles) by the overall radius of gyration of the structure, and at a small-scale (high angles) by the substructural radius of gyration. Scattering can be used to directly determine the mass-fractal dimension, the composition and these two main structural sizes, the smaller of which can be used to calculate the specific surface area of the material. Surface scattering from primary particles at high-q can also be used to determine the specific surface area using Porod's Law. In analogy with hydrocarbon polymers the primary particle, of such nano-scale structures, is similar to the persistence unit of a polymer chain. The primary particle of a mass-fractal is typically a 3-d object with a single radius of gyration whereas for polymer coils the persistence unit displays one-dimensional scaling (power-law of -1) between the persistence length and the diameter of a persistence unit [ST1-3, F6-7, F10, F12, F21, F25, F27-F32].

In addition to a 3-d primary particle there are several other main differences between ceramic based mass-fractals and polymer coils which are mostly based on the fact that polymer coils are subject to structural thermal equilibrium whereas ceramic chain aggregates are typically pre-determined in structure by irreversible kinetic growth laws. Some of these growth laws were determined at DuPont in pioneering work by Meakin and Scherer (now at Princeton) among other workers. Our efforts in this area began with structural characterization using combined scattering data from SALS, USAXS, SAXS and XRD. Such wide size-range data (typically 8 to 9 orders in size) displays many regimes of structure. For instance, in colloidal silica based aerogels produced by Smith's group at UNM [F21, F25] we have observed 4 easily distinguished levels of structure in scattering: primary particles (100Å), mass-fractal aggregates (500 Å), primary agglomerates (800Å) and micron scale mass-fractal aggregates of these primary agglomerates. Scattering from such complex structures displays transition regimes which must be described in a unified way in order to fully describe the complicated growth mechanisms involved.

2) UC efforts: One of the main successes is the development of new scattering functions which could describe these structural transitions and incorporate the existing scattering laws such as mass-fractal and surface fractal laws into a global description of data over such wide ranges of size [ST1-3]. At UC our efforts in this area have partly focused on the production of low thermal conductivity mass-fractal based polymer modified ceramic insulating materials [F2, F5, F16] and on silica and titania powder systems [F1, F9-10, F13]. Some of the latter work has involved collaboration with PPG, Dow Corning and Sortiris Pratsinis group at UC. Additionally, we have developed a new approach to the production of extremely high surface area silica and titania powders using a process which involves a combined sol-gel/aerosol reactor [F1. F9, F13]. The process is a hybrid of aerosol synthesis and hydrolysis condensation reactions. We have found that in a flameless aerosol process nano-pore collapse of sol-gel derived powders can be avoided by the rapid transport which occurs in small aerosol droplets. This is a completely novel approach to the synthesis of high surface area powders and offers a commercially viable route competitive with pyrolytic synthesis yet avoiding sintering of primary particles that occurs in a flame synthesis.

A number of collaborative efforts are underway involving scattering from sol-gel based systems including zirconia systems [F7, F12], colloidal crystals [F14], and zeolite systems [F4, F17, F19].

3) Carbon/PE composites: Parallel to efforts in inorganic systems we have been working for several years in a collaborative effort with K. Schwartz of Raychem on carbon black/polyethylene composites [F3]. This work is aimed at determining the mechanism behind structural transitions in self-resetting fuse materials through the use of USAXS and SAXS data.

4) Other Applications: We have recently worked on development of precursors to wear resistant metal coatings using pyrolytic and aero-sol-gel derived titania/organic materials with Ming Chen of the Airforce Research Laboratories. This work aims to create nano-scale hard (TiC) and soft (TiO₂) dispersed phases in a uniform surface film. This work is an outgrowth of a DAGSI proposal I wrote in 1999 with Ming. One student, Jim Chen is working on the development of amorphous mixed oxide epoxidation catalysts from ASG powders in collaboration with Joe Kulig at Goodyear Chemicals (NSF Proposal). A student shared with Jim Mark, Suresh Murugesan, in Chemistry is developing assymetric magnetic particles in elastomeric films for magnetic actuators in MEMS applications (NSF proposal planned). This work is an outgrowth of a previous DAGSI proposal with Prof. Ahn in Electrical Engineering.

A series of three papers were published concerning a new approach to the analysis small-angle scattering. The so called unified approach [ST1-3] provides a framework for dealing with scattering data that display multiple power-law and Guinier regimes. Generally, scattering laws are defined for small ranges of scattering vector, q. Examples of these are Porod's law, surface fractal power-laws, Guinier's law, and mass fractal power-laws. For some select cases scattering laws which deal with two regimes have been developed. Examples of these are the Debye Law for Polymer coils, the Debye-Bueche equation, special functions for spheres and rods and the Fischer-Burford equation for mass-fractals. In the unified approach a scattering pattern can be decomposed into one or more levels of structure each of which corresponds to a Guinier regime and a power-law regime. The unified approach describes both how a Guinier regime is related to a power-law regime within a level of structure, as well as how a series of related levels of structure can be joined to describe the compound scattering pattern from a complex material. It can be used, for example, to model polymer coils where the chain dimension deviates from a random walk [ST1]. It can also be used to describe the scaling transition from a Gaussian to a 1-d regime at the persistence length [PB3, PB4] as well as other structural scaling transitions in polymers [PB1]. The unified approach is quite general. It has been applied to both surface and mass-fractals [F1-F3, F5-F6, F8, F10-F11, F15-16, F18, F20-F21, F23, F25, F28-F31] as well as low-dimensional structures such as crystalline polymer lamellae[C1, C2].

Instrument development and support is a critical feature of our research program. At UMass [I2] a new instrument for SALS was developed which used a projected scattering image on a screen that was imaged using a macro-lens and a semi-conductor OMA camera. This design was very successful in studying wide angle scattering for spinodal decomposition in polymer blends. It is also an extremely flexible instrument and a write-up of the instrument was included in the first manuscript on the i-PVME/PS system [I2]. This design was copied in an instrument built at Sandia and transferred to UC which uses a 2-D CCD optical camera. SANS and SAXS work at UMass was done mostly at national user facilities at Argonne, Los Alamos, NIST and Brookhaven.

At Sandia, a scattering center based on two rotating anode generators was developed. This facility includes a pinhole camera, Kratky camera, Bonse-Hart camera and an Inel 120° wire detector based XRD camera equipped with a high temperature stage. A detailed description of this facility is available on the Web at:

http://www.sandia.gov/materials/sciences/Capabilities/Scattering/Scattering_Capabilities.html .

An x-ray reflectometer was also built based on the Kratky camera and designed so that the Kratky would be available as a dual use instrument [I1]. Development of this lab was a collaborative effort between a number of workers including D. W. Hua, now at Millennium Inorganic Chemicals (formerly SCM Chemicals) in Baltimore, T. Rieker who remains as lab manager at Sandia and Al Hurd, Paul Schmidt and Dale Schaefer as project managers.

At UC we have setup a Bonse-Hart camera, a Kratky camera and a Phillips diffractometer. These operate on a 12kW Rigaku rotating anode generator and a 5 kW Phillips tube source. We have also developed a novel ultra-low q SALS instrument which is capable of measurements up to several millimeters in size [paper in preparation]. This instrument has been useful in investigating mixing in polymer/solvent systems, inhomogeneties in elastomers, large scale agglomeration in powders, and in a project with P&G looking at a scaling description of fiber morphology in non-woven fabrics. The USALS instrument is based on critical reflection rather than the diffraction optics currently used in x-ray cameras. We plan to extent this approach to x-rays and should theoretically be able to enhance the resolution of current Bonse-Hart cameras using this approach. The State of Ohio has funded the development of a new pinhole SAXS camera under an instrumentation grant aimed at the study of silica and titania powders which is in collaboration with S. Pratsinis of the Chemical Engineering Department at UC with whom we have worked closely on inorganic powders. We are frequent users of the NIST Bonse-Hart Camera at BNL, as well as SANS and SAXS facilities at NIST, ORNL, Argonne, Sandia/UNM and Los Alamos. I am on the advisory panel for Argonne National Laboratories Intense Pulse Neutron Source (IPNS) for neutron scattering.

1) Initial Work, i-PVME/PS. Our work in the polymer blends area began with an industrially based project aimed at the development of phase-separated, rubber reinforced polystyrene using LSCT behavior [PB6, PB8, PB10-14]. Tactic PVME is a rubbery material with physical crosslinks based on crystallites. In phase-separated bulk samples shear banding can be introduced as a competitive energy absorption mechanism with crazing to lead to extremely tough styrenics. This work lead to a patent granted to Polysar Corporation. The work also required a detailed study of tacticity effects on miscibility in the PVME/PS system. Our approach was to look at structural changes in the PVME chains as a basis for changes in the interacting unit which are manifested in a shift in thermodynamic equilibrium. One of the most important conclusions from this work was that there is an association between the crystalline melting point and miscibility in blends where the crystalline component is too dilute to crystallize. This association explains strong dependencies of the statistical segment length on tacticity and temperature in the vicinity of the melting point.

2) Model Isotope Blends, PS/dPS, PDMS/dPDMS. In work at Sandia, these efforts were, to some extent, continued with the aim of focusing on model systems where complicating effects such as tacticity and polydispersity did not play a role. We initially focused on PS/dPS system with the aim of determining the molecular weight dependence of the interaction parameter. In addition to molecular weight effects one aim of this work was to determine the reason that data fits to the RPA equation are usually constrained to the first 10-15 data points of a data set consisting of about 250 points. This model system seemed ideal to study such features. Parallel to this work we were developing new tools to substitute for the Debye-equation for polymeric structures in inorganic mass-fractals as discussed above [ST1-3]. The conclusion from the PS studies were that a normal analysis using RPA approach and the Debye equation lead to unexplainable dependencies of the interaction parameter on molecular weight. This molecular weight dependency could be completely removed by allowing a slight deviation in the dimension of coils in this model blend from 2.0 for Gaussian chains to 2.1 for slightly collapsed chains. Additionally, the use of slightly collapsed coils allowed for fits to the entire data range [ST1].

In work at UC, in collaboration with Sandia, we have focused on the most flexible chain polymer, PDMS, in the hope of observing true Flory-Huggins behavior. Isotopic blends of PDMS were used in these studies. The results of this work support Gaussian scaling, yet a variable persistence length is still necessary to describe the behavior of R_g with temperature[PB4]. The unexpected dependence of statistical segment length on temperature can be explained using the "blob" approach of Degennes/Edwards coupled with Flory-Krigbaum approach for coil expansion. If this approach is taken a true Flory-Huggins interaction parameter can be obtained with no non-combinatorial entropy. This represents the first observation of an interaction parameter which follows the Flory-Huggins definition, i.e. the absence of a non-combinatorial entropy term. We believe that many of the deviations from Flory-Huggins behavior can be attributed to incorrect accounting of chain scaling in polymer blends.

3) Application of the Unified Equation to Chain Statistics, PHB's. We have also, been extending work on chain statistics and physical description using the unified function to describe the scaling transition from Gaussian to persistence scaling at the persistence length in biosource polyesters from P&G [PB3]. Our analysis of these systems shows an extremely large persistence length, associated with local coiling of these chains, yet a global Gaussian behavior for size-scales larger than the persistence length. These results are consistent with rheological measurements.

4) Extension of Chain Statistics Approach to Non-woven Fabrics. Funding for our blends/chain structure work comes from PRF-G and Procter and Gamble, paper division. The PRF grant supports basic research aimed at polymer blends. The paper/diaper division of P&G is aimed at a novel application of these concepts in the parameterization of structure in non-wovens used for the production of diapers on a micron to millimeter scale [PB2]. We have used a novel ultra-low angle light scattering instrument, pinhole SALS and Bonse-Hart x-ray camera to describe structure from about 1 mm to 100 Å in these materials. The main focus of these studies is to obtain a polymer-like description of these materials which would yield a fractal dimension, persistence length and overall radius of gyration for non-woven fibers just as we have obtained these values for real polymer chains. Several features of this work can be discussed in the open literature. In Glass Microfiber systems (very fine fiber-glass) the scaling of non-woven fibers can be easily determined using the unified function and light scattering data [PB2]. It is interesting that in this non-interacting system the equivalent of a chain scaling regime leads to a fractal dimension of 5/3 which matches theoretical predictions for self-avoiding walks. The persistence length measured with scattering corresponds with the average kink-length of these fibers. Scattering results such as persistence length and overall radius of gyration can be verified on a local scale using optical and scanning electron microscopy in this system. It is quite encouraging that scattering predictions for capillary absorption isotherms for this material match data obtained directly. Inherent to the scattering data is an understanding of the morphology which underlies features in the capsorption isotherm, indicating directions for the design of non-wovens with enhanced capillary absorption. We have recently investigated orientation in these materials using an adaptation of the Hermans Orientation function and SALS data. This information is being used to describe directionality in fluid flow and absorption in non-wovens on a millimeter to micron scale.

5) Chemically Driven Spinodal Decomposition. In addition to work on scaling effects in miscible polymer blends and chain conformation and adaptations in non-woven materials, we have recently been investigating the production of spinodal-like structures in chemically driven systems [APS Meeting, ACS meeting Las Vegas, ACS Fall Meeting Polymer Preprint 1997, paper in preparation]. Our focus here has been in PDMS/sol-gel systems where we have extensive exposure as described in the next section. We serendipitously found that some sol-gel/polymer systems can be chemically driven to produce irreversible, micron scale spinodal-structures which can be observed with the optical microscope or using pinhole SALS. The systems go through two stages of structural development. In a matter of minutes the PDMS chains are terminally crosslinked into a gel by a hydrolysis/condensation reaction with TEOS and TEOS like siloxanes (also for silane crosslinked systems). These gelled systems then develop spinodal structure over a period of hours to days depending on the PDMS network crosslink density and the chemical reaction driving the production of silica, i.e. the nature of the crosslinker/silica precursor. We believe that the spinodal structure is composed of silica domains and partially condensed TEOS. Current efforts are aimed at optimization of this structure for improved mechanical properties. Spinodal structures have been produced from a variety of silica precursors which involve a wide variety of chemistries. We have received assistance in the synthetic chemistry in this project from Jim Mark's group at UC and Mohamad Saraf of the University of Cairo.

1) Chlorinated polyethylene/PE Metallocenes. Our efforts in studying the morphology of crystalline polymers began with a CRADA with Dow Chemical while at Sandia which dealt with the morphology of low crystallinity systems. The results of these studies showed that the nano-scale structure of low-crystallinity polymers can display rod-like features in scattering as opposed to lamellar features. One-dimensional regimes can be observed both in metallocene elastomers as well as in CPE systems. In CPE strong evidence for phase separation exists. Most of the details of these studies are proprietary.

2) Semi-crystalline Polymer Foams. Low-density polymer foams for application as battery electrodes and as fusion targets are formed from semi-dilute solutions and supercritically dried after a solvent exchange process. These materials were originally thought to display mass-fractal scaling. Our work in this area has revealed that the structure is actually lamellar on a nano-scale [C2-C4]. It is interesting that these lamellae do not correlate, so that a correlation peak is absent in the small-angle scattering regime. This work proposes that the correlation of lamellae may be related to entanglements present in the melt which are essentially absent when crystallization occurs in semi-dilute conditions.

3) HDPE/LDPE/LLDPE. Extensive studies (much proprietary) have been carried out aimed at correlating orientation in blown films with mechanical and transport properties. The most successful of these involves a direct and linear correlation between moisture vapor transmission and orientation of lamellae observed in SAXS for HDPE blown films. For this work, the Hermans orientation function was calculated from 2-D SAXS patterns.

4) Biosource Polyesters. We have been working for about 2 years on polyesters derived from biosources with P&G's MVL facility. Most of this work is proprietary. Interesting structural features have been observed by combining SALS, SAXS and XRD in these systems. Structures intermediate between spherulitc and lamellar sizes seems to govern mechanical features of these systems. This is evidenced in blends of tactic and atactic PHB for example [paper in preparation]. There is also a correlation between the goodness of banding in these materials and this sub-spherulitic structure. Comparison with electron microscopy has revealed that the sub-spherulitic structure is related to regular clusters of lamellae.

1) Ellipsometry. Early work aimed at investigating the effect of layer thickness on the glass transition temperature of thin films showed a strong relationship in PS [IF5]. This work has recently been added to by an undergraduate research project by Mike Banach who has been funded by the Airforce through Rich Vaia of AFRL [IF1]. An NSF proposal is planned on the study of thin film dynamics using the spectroscopic ellipsometer of Prof. Boerio in our department.

2) Neutron/x-ray reflectivity. Model system studies of controlled molecular topology at interfaces [IF4, IF6-IF7].

3) Rough Interface Studies. We have been working for several years on a successful approach to describe scattering from rough surfaces through an analysis of high resolution reflection data using Argonne 2-D detectors (4096x4096 resolution) [IF2, IF3]. The approach is based on a combination of reflectivity and small-angle scattering. The systems studied were etched silicon and sol-gel based silica layers.

We have received a grant from NSF for a proposal on a novel approach to the production of nano-structured powders using chemical reactions in an aerosol. M. Roco, Program Director in Chemical and Transport Sciences at NSF has placed a poster on this process in the main lobby of NSF which demonstrates his shared excitement about this project. In addition to NSF funding the project has drawn the attention of industrial support and we have had several meetings with David Boldridge of the Cabosil Division of Cabot Corporation concerning funding and patenting of this technology. This project is an outgrowth of our interest in sol-gel chemistries and polymer-like, mass-fractal morphologies in inorganic systems and fits well with our strong interests in small-angle x-ray scattering from such systems [30 publications]. I have presented our work on the ASG reactor at the NSF/ESF joint conference on nano-structures in Edinburgh Scotland (1998) and presented more recent work on ASG elastomer reinforcement and catalyst development at the joint Swiss/US Nanoforum in Zurich Switzerland (1999).

We have worked on a project with an operating division of Procter and Gamble aimed at the use of a polymer analogy for the structure of non-woven materials. This project has included the development of a novel ultra-small-angle light scattering camera which can resolve large-scale structures. This is the first scattering camera capable of such resolution in the world and it opens a realm of problems which are of current interest to materials scientists throughout the world. (For example, the application of thermodynamic-like laws to the aggregation and packing of micron scale powders.) The non-woven materials field is ripe for a novel quantitative description of disorder structure which scattering can provide.

Early funding included a DOE grant for cooperative work with Sandia National Laboratories, Dow Corning Corporation and Dow Chemical Corporation. This project focused on characterization of morphology in chlorinated polyethylene and in situ filled siloxane elastomers. The project resulted in 15 publications and supported 4 graduate students. Several important results came of this effort including an understanding of the morphology of low-crystallinity polymers, development of models for the growth of in situ produced ceramic phases in siloxane elastomers and the effect of processing on morphology in filled siloxane elastomers and in low-crystallinity polymers. Parallel to the siloxane elastomer work two students have worked on the development of super-insulating ceramers under partial funding of Armstrong World Industries. Nano-scale pores can be produced using sol-gel chemistry. Typically such solution chemistry leads to powders which display macro-pores through which the majority of transport occurs. In our ceramer work [3 papers] addition of small amounts of PDMS elastomer to solution derived nano-ceramics can alleviate drying stresses which lead to cracking of monoliths of these materials. Cost estimates show that these ceramers could be a commercially viable alternative to urethane insulation materials which require the use of chlorinated fluorocarbons for their production. We have also received a substantial grant from Miami Valley Laboratories of Procter and Gamble to extend our work in semi-crystalline polymers in the study of biosource polyesters. Biosource polyesters such as polyhydroxybutyrate (PHB) are seen as an alternative to non-degradable polymers such as polyethylene. PHB produced from bacteria is biodegradable but lacks the physical properties necessary to form blown films such as are used in garbage bags and diapers. Through chemical modification and melt blending, properties can be enhanced at a competitive price. The manipulation of these crystalline structures on a nanometer to micron scale is critical to the use of these materials in a variety of environmentally friendly consumer products. Equistar Chemicals LP (formerly Quantum Chemical) has supported our efforts in crystalline polymers with a small grant, $21,000 and continuing support of small-angle scattering work on oriented polymers. In these efforts we have determined a direct, quantitative correlation between the orientation of lamellar crystals in high density polyethylene and moisture vapor transmission. This is a critical correspondence with the primary property for such applications as "Corn Flake" bags. We are continuing efforts in the area of nanometer to micron scale orientation studies using small-angle scattering.

Our main area of expertise is in small-angle scattering. This technique is, in some ways, and outgrowth of diffraction techniques. Parallel to diffraction, information is obtained on morphology in terms of intensity versus angle plots. At small-angles relatively large structural sizes are probed, 1 Ångstrom to 1 micron using x-rays and neutrons and 1 micron to 1 millimeter using laser light. These colloidal scale sizes are of critical importance to industrial materials ranging from polymers to soaps. The information obtained from small-angle scattering pertains to average properties making it useful for studies of disordered materials and in the direct determination of thermodynamic parameters. We have strong capabilities in equipment and facilities due mostly to donations and loaned equipment from Sandia, Oak Ridge and Quantum Chemical. We currently have equipment for small-angle scattering in 410 Rhodes Hall and in 551 ERC which is the equal of any scattering facility in the world. The facilities include unique light scattering cameras which extend our range of observable size to the millimeter level, as well as extensive x-ray scattering facilities. Using small-angle scattering from these facilities we can access sizes from the millimeter level to the Ångstrom level continuously so as to determine the relationship between morphological features on widely disparate size-scales. This equipment is being used to characterize complex morphologies in a variety of systems ranging from polymer blends to industrial ceramic powders. We are also using our scattering facilities to demonstrate the application of new theoretical approaches to polymer thermodynamics and other disordered materials.

As noted in the CV section, above, we are frequent users of National Facilities and have active working relationships with all of the current neutron scattering facilities in the US. Neutron scattering is used as an alternative to x-ray scattering since selective deuteration (substitution of deuterium for hydrogen) leads to high neutron contrast while leaving the chemistry and thermodynamics of systems virtually unchanged. In effect, one can paint a single polymer chain red using deuterium and study its static's and dynamics in the melt for instance. We have also recently begun studies of conducting polymers in the solid state taking advantage of contrast changes which occur for neutrons when the chains are in the conducting state. This work is in collaboration with Harry Mark of the Chemistry Department at UC and represents the first studies of chain morphology in these generally insoluble materials.

I initiated and developed several NSF center proposals involving Organo-silicon Technologies, one of which is included in the proposals section. Although all of these proposals were eventually rejected, the one included in this application made it to the second level of review. I have also authored a large joint proposal on similar lines with S. E. Pratsinis and J. E. Mark focusing on elastomer reinforcement with silica nano-particles. I am currently participating in the Membrane center proposal that is growing out of the Chemical Engineering Department.

The pending proposals section includes copies of two submitted NSF proposals and a DAGSI proposal that will be submitted. These proposals focus on the development and application of the aero-sol-gel process (previously funded by NSF) catalysts, as polymer fillers and UV absorbents and as precursors to dual-phase, hard/soft coatings for wear resistant metals (DAGSI). Both of the NSF proposals are targeted at Mike Roco's Program at NSF and I have been in frequent contact with Mike concerning developments and funding potential.

In addition to these a proposal to the Petroleum Research Fund focusing on determination of polymer chain scaling features and the use of this information to predict physical properties such as non-Newtonian polymer flow is planned in the fall. This proposal is an outgrowth of an earlier PRF grant as well as a recent paper [PB1] that is included in the pending proposals section. This will be a $90,000 3-year AC proposal.

Adel Halasa at Goodyear Tire and Rubber is in the process of submitting an internal proposal to fund our work on ASG powders as elastomer reinforcing agents. This will be a 2 year project on the order of $150,000 to $200,000. The details of this work are still being worked out and it may involve collaboration with Sotiris Pratsinis, Dale Schaefer and Jim Mark similar to a previous NSF group proposal submitted in 1998.

I am planning an NSF proposal on measurement of the dynamics of thin polymer films using Prof. Boerio's spectroscopic ellipsometer. This work is an outgrowth of polymer electro-optics work done by Mike Banach (BS 99) and a copy of Mike's paper on this subject (submitted Macromolecules) is also included.

Additionally, I am planning an NSF proposal in late fall or winter dealing with the development of nano-scale asymmetric magnetic particles in elastomeric matrixes following an in situ route. This work will focus on a previous DAGSI proposal with Prof. Ahn in Electrical Engineering where such polymer films were intended as MEMS actuators for applications such as controlled drug delivery. A shared Chemistry PhD student (with J. E. Mark), Suresh Murugesan, has already done preliminary work in this area.

In addition to these proposals planned in the next 6 months, I will participate in the Membrane Center proposal being formulated in the Chemical Engineering Department. I believe that my previous experience with center proposals will be a contribution to this effort. A copy of the previous proposal to NSF which I initiated and wrote for an Organo-Silicone Materials Center is included for reference. I have also included an example of an industrial contract report done for P&G on Non-Woven Materials as an example of our efforts. This work was published [PB2].