Verification of the Schulze-Hardy Rule: A Colloid Chemistry Experiment

Nowicki, Waldemar; Nowicka, Grażyna

doi:10.1021/ed071p624

Cited by 47 publications

(27 citation statements)

References 1 publication

(1 reference statement)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3d). This fits with the observations by Liang and Morgan (1990), who concluded that Ca is more effective than Na as a coagulant of Fe 2 O 3 particles as can be qualitatively predicted by the SchulzeHardy rule (Nowicki and Nowicka, 1994). ADVA ® Cast 550 stabilized the Fe 2 O 3 colloids to higher concentrations of Ca(OH) 2 , keeping the Zeta potential of the colloids around neutral values.…”

Section: Effect Of Phsupporting

confidence: 89%

Inhibition of the formation and stability of inorganic colloids in the alkaline disturbed zone of a cementitious repository

2015

View full text Add to dashboard Cite

The generation and stability of inorganic colloids have been studied under hyperalkaline conditions. For the generation of colloids, intact cores of Bromsgrove Sandstone were flushed with simulated cement leachates, and the eluates were ultrafiltered sequentially (12 µm, 1 µm, 0.1 µm and 30 kDa) for the separation of any colloids found. No colloid formation was observed during the experiments; however the analysis by ICP-MS of the eluates showed significant increases in Si and Al, indicating silicate mineral dissolution, as well as reduction of the concentration of Ca in the leachates indicating precipitation of secondary Ca-rich phases. Flow experiments with cement leachates spiked with tritiated water showed a noticeable reduction of the porosity of the sandstone as well as changes in the pore distribution. Additional stability experiments were carried out using model silica and Fe 2 O 3 colloids. The experiments indicated that the stability of the colloids was mainly controlled by the concentration of Ca in solution and that both types were unstable under the chemical conditions in the alkaline disturbed zone. The presence of cement additives such as superplasticisers could enhance the stability of the colloids.

show abstract

Section: Effect Of Phsupporting

confidence: 89%

Inhibition of the formation and stability of inorganic colloids in the alkaline disturbed zone of a cementitious repository

2015

View full text Add to dashboard Cite

show abstract

“…[10] However, synthesis of atomically precise alloy QCs of various compositions is a challenge. [11] Murray et al synthesized Pd@Au 24 (SR) 18 which was further studied by Negishi et al [ 11b] Negishi et al isolated PdAu 24 (SR) 18 .…”

mentioning

confidence: 99%

“…Ag n Au 25Àn (SR) 18 , and (AuAg) 140 (SR) 60 (R = organic soluble alkyl/aryl groups) were obtained by simultaneously reducing metal salts in suitable conditions. [11c,d] There is also a family of well-characterized Ag/ Au/Cu cluster complexes [12] that are different from the metal core clusters discussed herein.…”

mentioning

confidence: 99%

“…Indeed, the addition of Au I thiolate to pure PAGEseparated Ag 8 clusters also forms the desired product. The addition (of more than the optimized mount) of HAuCl 4 to crude Ag 7,8 clusters produces plasmonic nanoparticles, and further addition leads to charge neutralization according to the Schultz-Hardy rule, [18] resulting in coagulation and settling. This residue was analyzed using TEM, SEM, and a luminescence image, which shows the presence of tubular arrangement of nanoparticles (Supporting Information, S13).…”

mentioning

confidence: 99%

See 1 more Smart Citation

Ag₇Au₆: A 13‐Atom Alloy Quantum Cluster

et al. 2012

View full text Add to dashboard Cite

An alloy cluster containing a 13‐atom core, with a composition Ag7Au6(H2MSA)10 (H2MSA=mercaptosuccinic acid) was synthesized from silver clusters by a galvanic exchange reaction. The clusters were characterized by several spectroscopic and microscopic methods. The alloy cluster shows luminescence with a quantum yield of 3.5×10−2 at room temperature. Theoretical calculations for Ag7Au6(SCH3)10 suggest a distorted icosahedral core.

show abstract

“…This is because CCC is very sensitive to the valence of counterions. As indicated by the Schulze-Hardy rule, 27,28 for low surface potential colloid systems, the CCC is inversely proportional to the second power of the counterion valence; for high surface potential colloid systems, the CCC is inversely proportional to the sixth power of the counterion valence. Figure 5 shows the titration results with the two monovalent salts.…”

Section: Effects Of Titrant Type Titrant Concentration and Titratiomentioning

confidence: 99%

Critical Coagulation Concentration–Based Salt Titration for Visual Quantification in Gold Nanoparticle–Based Colorimetric Biosensors

Lü

Zou

2014

SLAS Technology

View full text Add to dashboard Cite

In gold nanoparticle (GNP)-based colorimetric biosensors, the gradual color shift is often used to correlate with the concentration of target molecules, and therefore a UV-vis spectrometer is usually required for accurate quantification.Here, we present a critical coagulation concentration (CCC)-based salt titration as a generic and simple way to enable accurate quantification in GNP-based colorimetric biosensors without any analytical equipment. The titration is carried out by stepwise addition of a salt titrant to the premixture of sample and GNPs until the color changes rapidly from red to blue, determined solely by visual inspection. The number of titration steps or the final salt concentration required for a rapid color shift (i.e., CCC) is then used to quantitatively correlate with the concentration of target molecules in the sample. The salt titration-based quantification has been demonstrated with two previously reported GNP-based colorimetric biosensors. Compared with quantification based on the gradual color shift with a spectrometer, the visual quantification based on the rapid color shift in the salt titration eliminates the need for any analytical equipment without sacrificing the performance (i.e., sensitivity and accuracy) and therefore is highly suitable for applications in low-resource settings.

show abstract

Verification of the Schulze-Hardy Rule: A Colloid Chemistry Experiment

Abstract: A simple and inexpensive experiment for verifying the Schulze-Hardy rule.

Cited by 47 publications

References 1 publication

Inhibition of the formation and stability of inorganic colloids in the alkaline disturbed zone of a cementitious repository

Inhibition of the formation and stability of inorganic colloids in the alkaline disturbed zone of a cementitious repository

Ag₇Au₆: A 13‐Atom Alloy Quantum Cluster

Critical Coagulation Concentration–Based Salt Titration for Visual Quantification in Gold Nanoparticle–Based Colorimetric Biosensors

Contact Info

Product

Resources

About

Verification of the Schulze-Hardy Rule: A Colloid Chemistry Experiment

Abstract: A simple and inexpensive experiment for verifying the Schulze-Hardy rule.

Cited by 47 publications

References 1 publication

Inhibition of the formation and stability of inorganic colloids in the alkaline disturbed zone of a cementitious repository

Inhibition of the formation and stability of inorganic colloids in the alkaline disturbed zone of a cementitious repository

Ag7Au6: A 13‐Atom Alloy Quantum Cluster

Critical Coagulation Concentration–Based Salt Titration for Visual Quantification in Gold Nanoparticle–Based Colorimetric Biosensors

Contact Info

Product

Resources

About

Ag₇Au₆: A 13‐Atom Alloy Quantum Cluster