Humidity sensing with weak acid-doped polyaniline and its composites

Henderson-Hasselbalch relation is generally the simplified theoretical framework used to introduce students to acid-base titration. However, it is not always valid and its limitations should be made clear to chemistry students. The appropriate parameter to evaluate its validity is K a /C 0 , in connection with Ostwald dilution law. For more advanced students, it is possible to deduce analytical expressions that always fit accurately acid-base titrations and allow an evaluation of Henderson Hasselbalch relation. Gran plot appears as a particularly sensitive technique to the breakdown of Henderson Hasselbalch relation.

Download Full-text

Use of Low Pressure Mercury Lamps for the Photodecomposition of Iron Cyanide in Gold Mill Effluents

Water Quality Research Journal ◽

10.2166/wqrj.1985.022 ◽

1985 ◽

Vol 20 (2) ◽

pp. 111-119 ◽

Cited By ~ 1

Author(s):

J.H. Carey ◽

S.A. Zaidi

Keyword(s):

Ultraviolet Light ◽

High Intensity ◽

Experimental Evaluation ◽

Low Pressure ◽

Pilot Scale ◽

Weak Acid ◽

Potassium Ferricyanide ◽

Technical Feasibility ◽

Iron Cyanide ◽

Scale Test

Abstract The use of ultraviolet light (UV) from low pressure mercury lamps for destroying iron cyanide in synthetic and actual gold mill effluents was evaluated in this study. For the light intensities used in this study, UV irradiation was not able to efficiently destroy cyanide. However, it converted iron cyanide to a weak acid dissociable form which was destroyed by chlorine. Data from several bench-scale tests and one pilot scale test were used to estimate quantum efficiencies (moles iron cyanide destroyed/einstein). These efficiencies ranged from 0.2% to 1%; approximately 30% to 90% lower than those reported in the literature for potassium ferricyanide. The data collected during the study demonstrated the technical feasibility of using UV in conjunction with chlorination for destroying iron cyanide in gold mill effluents. However, low pressure mercury lamps do not appear to be a practical UV source for this purpose. Irradiation with high intensity lamps may be more practical and is recommended for experimental evaluation.

Download Full-text

Controlled Growth and Characterization Ag/ZnO Nanotetrapods for Humidity Sensing

Combinatorial Chemistry & High Throughput Screening ◽

10.2174/1386207321666180717120417 ◽

2018 ◽

Vol 21 (7) ◽

pp. 462-467

Author(s):

Babak Sadeghi

Keyword(s):

Room Temperature ◽

Zinc Complex ◽

Water Solution ◽

Particle Morphology ◽

Quick Response ◽

Separation System ◽

Humidity Sensing ◽

Sensor Material ◽

Highly Sensitive

Aim and Objective: Ultrafine Ag/ZnO nanotetrapods (AZNTP) have been prepared successfully using silver (I)–bis (oxalato) zinc complex and 1, 3-diaminopropane (DAP) with a phase separation system, and have been injected into a diethyl/water solution. Materials and Methods: This crystal structure and lattice constant of the AZNTP obtained were investigated by means of a SEM, XRD, TEM and UV-vis spectrum. Results: The results of the present study demonstrated the growth and characterization AZNTP for humidity sensing and DAP plays a key role in the determination of particle morphology. AZNTP films with 23 nm in arm diameter have shown highly sensitive, quick response sensor material that works at room temperature.

Download Full-text