Hollow glass microspheres

A simple way of reducing the weight of the battery is to use lightweight fillers in the plates. If the filler replaces active material that does not contribute to the energy of the battery, the specific energy can increase dramatically. One type of filler material 

Plate type Stoichiometric capacity (Ah) Measured utilization, Cave. (%) 

One disadvantage to using filler-type additives, such as glass microspheres, is that there will most likely be an increase in the battery volume. The increased volume will degrade the energy density of the battery. Depending on the application, this trade-off may be acceptable. 

Attempts to assist the supply of acid to the positive active-material have focused on increasing the porosity of the paste to enhance diffusion or by providing fine local reservoirs of acid within porous particles throughout the plate [4]. One such 

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Results of uniaxial strain static and gas gun compression tests on syntactic foam have been conducted. The foam was buoyant and composed of hollow glass microspheres (average diameter 100 microns) embedded in an epoxy plastic. Static testing consists of compressing a 0.25 cm x 2.5 cm dia. wafer between carefully aligned 2.5 cm dia. steel pistons. Lateral expansion of the wafer is... 

Schmitt, M.L., J.E. Shelby and M.M. Hall, Preparation of hollow glass microspheres from sol-gel derived glass for application in hydrogen gas storage. /. Non-Crystalline Solids, 352, 626-631,2006. 

Solid and hollow glass microspheres have been made for many years for a variety of applications. Fabrication techniques involving formation of microspheres were pioneered by Beck7 and later expanded by Howell8 and Marshall9. 

ENCAPSULATION OF PALLADIUM IN POROUS WALL HOLLOW GLASS MICROSPHERES... 

The experimental work involved two parts. The first part was to produce porous wall hollow glass microspheres. The second part was to fill the PWHGMs with palladium. 

Fabrication of Porous Wall Hollow Glass Microspheres (PWHGMs)... 

Figure 1. Flame former for producing hollow glass microspheres.

The HGMs produced were heat treated at 620 °C for 18 hours before they were leached in 4 molar HC1 solutions at 80 "C for 4 hours. Heat treatment produced phase separation which resulted in a silica-rich phase and a more soluble and interconnected, sodium borate phase. Leaching removed the soluble sodium borate phase of the glass and created porosity through the microsphere walls. The porous wall, hollow glass microspheres, sank to the bottom of the solution. These sinkers were collected, water washed and dried at 100 °C overnight. 

The porous wall hollow glass microspheres were filled with palladium by a soak-and-dry process followed by hydrogen reduction. Saturated solutions of palladium salt were prepared at room... 

The floaters collected in the flame forming step were hollow glass microspheres (HGMs). The size of the microspheres were in a range from about 5 to 150 microns with a true density of about 0.4 g/cc as measured using a helium pycnometer. The wall thicknesses were estimated to be between 1 to 5... 

Fig. 24. Relative shear modulus of a PMMA/hollow-glass microspheres syntactic foam 67 1) values calculated with a uniform shell thickness of 1.2 pm and Gh/G0 = 1.01 2) values calculated with a shell thickness of 0.6 pm and GH/G = 0.5. Filled circles are the experimental data of Kinra and Ker at 1 MHz1371...

Polyimide-Based Syntactic Foam (9). Three-phase syntactic foams were made using a polyimide solution (22% PI-2080 in DMF) and hollow glass microspheres (Type B-30-B, 3M Co.) which have a particle density of 0.25 to 0.30 cm and a bulk density of 0.182 g/cm . The solution and glass spheres were hand mixed and packed into a 5" x 5" mold and compacted under pressure. Variations of foam density were obtained by molding specific quantities of blend into different volumes ranging from Vi to 1" in thickness. Greater densities required higher pressures with the maximum density obtained at a pressure of about 100 psi. 

Revision A of this specification was published 10 March 1957. There are two types. Type I for 4,5000 psig hydrostatic pressure and Type II for 10,000 psig. The QPL was cancelled on 31 March 1986. The syntactic buoyancy material consists of a low-density filler such as hollow-glass microspheres in a resin matrix such as epoxy resin. 

Spherical glass material, solid and hollow glass microspheres in ranges of particle size 1-515 pm to be used as standards in scientific studies on sedimentation, separation, insulation, reflection and... 

Delzant M, A Contribution Towards Studying the Behavior of Composites Containing Microperl Solid and Microcel Hollow Glass Microspheres or a Combination of Fibers and Spheres as Fillers. Abrasivos Y Maquinaria, S A, Barcelona, Spain. 

Solid Glass Beads and Hollow Glass Microspheres in the Service of Industry. Abrasivos Y Maquinaria SA, Barcelona, Spain. 

Hollow glass microspheres can be added to POs as a way of stiffening the resin system while also reducing its density substantially. Microspheres that are used as plastics fillers have typically only about 0.6g/cm density, much lower than standard fillers (with densities of 2.7-2.9). The low density hdps make... 

Tres PA. Hollow glass microspheres. Plastics Technol [trade journal] May 2007. 

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