Wet volume capacity

Fig. 2. Total capacity vs cross-linkage for polystyreae sulfonic acid resin in the form where A and B correspond respectively to dry and wet weight capacity in meq/g of resin, and C represents wet volume capacity in meq/mL of wet setded resin.

Values typical of standard resins. WVC = wet volume capacity)... 

BOX 4.7 Determination of Strong and Weak Base Wet Volume Capacity of an Anion Exchange Resin... 

Sole The value D may be used to derive or to check the total wet volume capacity ( VV(>). I) VC> mcej/g xg/ml = VV ( met /ml. Since the maximum error in VV( is the volume measurement, the determination of several D values to obtain a mean value will give a more accurate V (2 lietermination than a direct measurement. 

High operating capacity high wet volume capacity (WVC) low crosslinking small beads low selectivity... 

A sample of phosphonic acid resin Diaion CRP200 in wet Na+ form was kindly provided from Mitsubishi Chemical Co. Ltd. This wet resin sample was dried in vacuum, and then the resin with particle sizes of 60 - 32 mesh was selected by meshing. The selected resin was conditioned by treatment with 1 M HC1, water, 2 M NaOH, water, 1 M HC1, and water in successive. Finally, thus, the resin was changed into H+ form. The phosphorus content and acid capacity of the selected resin in the H+ form were measured according to the reported methods and were 4.6 mmol/g and 8.8 meq/g, respectively. Wet volume of the resin was 2.6 ml/g. Hereafter, this is abbreviated as CRP200 for simplicity. 

One commercial resin is the AG 11A8 polymer made by Bio-Rad. These can be obtained prepacked with 10 mL bed volumes. The particle size varies from 180 to 300 pm with a wet bed capacity of 0.7 meq/mL. The approximate m.w. exclusion is 1000. The resin can be used from pH 0 -... 

Relative Kga valid for all systems controlled by mass transfer coefficient (Kg) and wetted area (a) per unit volume of column. Some variation should be expected when liquid reaction rate is controlling (not liquid diffusion rate). In these cases liquid hold-up becomes more important. In general a packing having high liquid hold-up which is clearly greater than that in the falling film has poor capacity. 

C is an apparatus constant. Usually C, a, and KH are temperature dependent, but a and Kh more so than C. Also In (a) behaves analogously to VPIE and normally increases as temperature falls according to 1/T or 1 /T2 (Chapter 5), while KH typically increases exponentially as temperature falls. These two criteria conflict so far as the best choice of temperature is concerned, and for good separations it is necessary to determine the optimum compromise. With a and KH set by the selection of operating system and temperature, resolution is proportional to Vg/Vc. For maximum resolution the vapor volume is increased by electing open tubular columns, i.e. wetted wall columns with minimal liquid loading, and therefore minimal capacity. 

To be an acceptable substitute for wet collectors and to satisfy the NIOSH criterion for acceptable methods, a sorbent material must have a demonstrated sorption capacity for the analyte that is adequate for sampling a reasonable volume of workplace air at an established rate. Typically, a sample volume of at least 12 L (1 h at 0.2 L/min) is desirable. 

All of the silane treatments in this study diminish the physisorptive capacity of glass fiber substrates, as shown by the isotherms (Fig. 2) and the desorption volumes of physically adsorbed water (Table 4, peak 1). This is one reason for their efficacy at promoting wet strength retention and enhancing other composite properties that degrade when moisture adsorbs at the fiber-matrix interface. Chemisorptive properties for probe adsorbates that are imparted to the substrate by silane deposition may also influence fiber-matrix interaction. 

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