Suspension impregnating

Operating pressure 1.2 bar Catalyst material formation 3oTi7oOx Si02 suspension + impregnation finally anodic oxidation... 

Figure 10. Propene polymerization profiles of a silica-supported metallocene/MAO catalyst prepared by suspension impregnation (a) depending on polymerization time and polymerization temperature and (b) depending on particle size and polymerization time, (c) Comparison of the activity profiles between an 1-octene prepolymerized catalyst and an untreated system, (d) Comparison of the activity profiles between a catalyst system employing 2 vol % hydrogen and the not activated system.

Chemical Warfare Board Project No. 298, Test of Mobile Water Suspension Impregnating Plant, 31 Aug 43. (2) CWTC Item 863, Military Requirements and Military Characteristics for a Mobile Impregnating Unit, 3 Dec 43. (3) CWTC Item 993, Military Requirement and Military Characteristics for a Kit for Conversion of Mobile Laundry Units for Impregnation, 5 May 44. See also Item 1090, 7 Jul 44, same title. 

Early work on the use of foams and mats has been reviewed [9j. Nickel fiber, nickel-plated steel fiber, or nickel-plated graphite fiber mats are preferred because they have smaller pores ( 50(im) [14]. The most recently developed mats can have porosities as high as 95% [13] and are much lighter than the sintered nickel plaques, which typically have porosities between 80 and 90%. Initially, standard cathodic impregnation methods were used to load the active material into the foam [9]. More recently, the preferred method is to incorporate the Ni(OH)2 in the form of a slurry into the mat [13, 14]. This has been called the suspension impregnation method [14]. Considerable improvement in the Ni(OH)2 has been achieved by the addition of divalent Co compounds to the slurry. The best results... 

Bead Processes. These processes have generally replaced the above techniques. The styrene is polymerised by bead (suspension) polymerisation techniques. The blowing agent, typically 6% of low boiling petroleum ether fraction such as n-pentane, may be incorporated before polymerisation or used to impregnate the bead under heat and pressure in a post-polymerisation operation. 

Angiotensin II. Male Sprague-Dawley rats (300-400 g) were administered either free angiotensin II (A-H) (Sigma product A9525, human synthetic A-H, Asp-Arg-Val-Tyr-Ile-His-Pro-Phe) in 0.9% NaCl solution by subcutaneous injection, or A-H impregnated resin by gastric intubation. The resin was suspended in distilled water such that the rat received no more than a 0.5 mL total suspension volume. The... 

Catalysts - A commercial Raney nickel (RNi-C) and a laboratory Raney nickel (RNi-L) were used in this study. RNi-C was supplied in an aqueous suspension (pH < 10.5, A1 < 7 wt %, particle size 0.012-0.128 mm). Prior to the activity test, RNi-C catalyst (2 g wet, 1.4 g dry, aqueous suspension) was washed three times with ethanol (20 ml) and twice with cyclohexane (CH) (20 mL) in order to remove water from the catalyst. RCN was then exchanged for the cyclohexane and the catalyst sample was introduced into the reactor as a suspension in the substrate. RNi-L catalyst was prepared from a 50 % Ni-50 % A1 alloy (0.045-0.1 mm in size) by treatment with NaOH which dissolved most of the Al. This catalyst was stored in passivated and dried form. Prior to the activity test, the catalyst (0.3 g) was treated in H2 at 250 °C for 2 h and then introduced to the reactor under CH. Raney cobalt (RCo), a commercial product, was treated likewise. Alumina supported Ru, Rh, Pd and Pt catalysts (powder) containing 5 wt. % of metal were purchased from Engelhard in reduced form. Prior to the activity test, catalyst (1.5 g) was treated in H2 at 250 °C for 2 h and then introduced to the reactor under solvent. 10 % Ni and 10 % Co/y-Al203 (200 m2/g) catalysts were prepared by incipient wetness impregnation using nitrate precursors. After drying the samples were calcined and reduced at 500 °C for 2 h and were then introduced to the reactor under CH. 

The catalyst used throughout this study was prepared by impregnation. To a slurry of silica (M5 Cab-O-Sil, Surface Area 200 m2g 1) in water sufficient copper nitrate solution was added to give a loading of 8.6 % w/w Cu. The resulting suspension was dried at 353 K until a free flowing powder was obtained. 

Prior to functionalization the carbon nanomaterials were washed in concentrated nitric acid (65% Fisher Scientific) for 8 h using a Soxhlet device in order to remove catalyst residues of the nanomaterial synthesis as well as to create anchor sites (surface oxides) for the Co on the surface of the nanomaterials. After acid treatment the feedstock was treated overnight with a sodium hydrogen carbonate solution (Gruessing) for neutralization reasons. For the functionalization of the support media with cobalt particles, a wet impregnation technique was applied. For this purpose 10 g of the respective nanomaterial and 10 g of cobalt(II)-nitrate hexahydrate (Co(N03)2-6 H20, Fluka) were suspended in ethanol (11) and stirred for 24 h. Thereafter, the suspension was filtered via a water jet pump and finally entirely dried using a high-vacuum pump (5 mbar). 

Simply impregnating paper with formaldehyde and drying gives some limited wet strength, but it also causes brittleness and suffers from the problem of odour. The condensation product of formaldehyde and urea, 1,3-dihydroxymethylurea (Figure 7.23), is also effective, but it is water soluble and not substantive to cellulosic fibres in aqueous suspension. 

It was possible to cover additional applications with these new types. In 1951 BASF found it was possible to impregnate polystyrene direct with expanding agents in the suspension process. This opened up great new possibilities for polystyrene foam (STYR0P0R, BASF, 33), for example in the packaging and building fields. 

The colloidal suspensions obtained by the neutralization or thermohydrolysis procedures described previously have been used to prepare supported Pd catalysts. The support is impregnated with a volume of colloidal oxide suspension corresponding exactly to the porous volume of the solid, according the well-known incipient wetness impregnation. 

Impregnating a basic colloidal suspension (pH = 12) on alumina does not induce proton liberation, thus the pH is constant (Fig. 13.25b). The system keeps its initial properties, i.e. negative charges for alumina support and PdO particles. Repulsive interactions are created between the alumina surface and the PdO particles so that the particles deposited on the support are redispersed, and finally isolated from each other. 

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