Difference between revisions of "Silica gel, commercial"

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==Resources and Citations==
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== Resources and Citations ==
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* AIC Conservation Wiki: [https://www.conservation-wiki.com/wiki/Category:Exhibit_Technical_Notes Exhibit Technical Notes: Environmental Control]
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* Exhibit Guidelines Technical Note: [https://www.conservation-wiki.com/wiki/Silica_Gel_Products_and_How_to_Use_Them Silica Gel Products and How to Use Them]
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* Exhibit Guidelines Technical Note: [https://www.conservation-wiki.com/wiki/Conditioning_Silica_Gel Conditioning Silica Gel]
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* Exhibit Guidelines Technical Note: [https://www.conservation-wiki.com/wiki/Conditioning_Silica_Gel_with_a_Saturated_Salt_Solution Conditioning Silica Gel with a Saturated Salt Solution]
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* J.Tétreault, P.Bégin, [https://www.canada.ca/en/conservation-institute/services/conservation-preservation-publications/technical-bulletins/silica-gel-relative-humidity.html Silica Gel: Passive Control of Relative Humidity], CCI Technical Bulletin no. 32. Canadian Conservation Institute. Ottawa (2017).
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* Art Preservation Services: [https://www.apsnyc.com/silica-gel-technical-information Silica Gel Technical Information]
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* S. Weintraub, "Demystifying silica gel", Objects Specialty Group Postprints, Vol.9, p. 169-194, 2002 [http://resources.culturalheritage.org/osg-postprints/wp-content/uploads/sites/8/2015/02/osg009-12.pdf Link]
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[[Category:Materials database]] [[Category:MWG]] [[Category: Climate/Environment]][[Category: Comparisons]]
 
[[Category:Materials database]] [[Category:MWG]] [[Category: Climate/Environment]][[Category: Comparisons]]

Revision as of 13:09, 20 July 2023

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Description

The moisture adsorbing properties of silica gels are affected by factors such as capillary pore size or the inclusion of hygroscopic salts, resulting in a wide range of performance. Thus, it is important to compare the buffering capacity of different types of silica gels to determine which has the best performance for a specific application. In 1977, Thomson described the specific moisture reservoir with the variable M where M represents the amount of water (in grams) that is gained or lost by 1 kilogram of silica gel for each 1% change in RH. However for any specific silica gel type, M can vary widely due to the expected RH range and the hysteresis of the adsorption/desorption curve. In order to compensate, a new value called MH has been defined as the average amount of water (in grams) that is gained or lost by 1 kilogram of silica gel for each 1% change in RH. This is determined by repeatedly cycling silica gel between adsorption and desorption within a specific RH range until a constant value is measured.

Table 1: Specific moisture reservoir (g/kg for a 1% RH change) at 20°C *

Moisture sorbent MH 50 ± 10% M 20 → 30% M 60 → 50% Recommended for Recommended for
RH around 50% Keep RH low Keep RH high Temp exhibit case in room with good to moderate climate control Maintenance-free exhibit case
RHapid Gel 6.11 ± 2.16 4.48 ± 0.42 4.38 ± 1.40 2 kg/m3 4 kg/m3
PROSorb 5.42 ± 1.32 4.37 ± 0.10 4.25 ± 0.38
Art-Sorb 4.04 ± 0.80 2.84 ± 0.47 4.18 ± 0.49 4 kg/m3 8 kg/m3
Arten Gel 5.7 5.5
Regular density silica gel (clear, type A) 1.93 ± 0.44 5.48 ± 0.40 1.47 ± 0.16 9 kg/m3 18 kg/m3
Orange silica gel 1.16 ± 0.26 4.92 ± 0.59 0.94 ± 0.14
Bentonite clay (Desi Pak) 1.19 ± 0.07 2.25 ± 0.03 1.11 ± 0.02
Molecular sieves 4A (zeolite) 0.33 ± 0.02 0.47 ± 0.04 0.31 ± 0.01

Resources and Citations

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