Organic Phosphorus Compounds as Inhibitors of Corrosion of Carbon Steel in Circulating Cooling Water: Weight Loss Method and Thermodynamic and Quantum Chemical Studies

<table class="table-group" id="tab3"><tr><td><table class="table"><tr><td class="thead-hr" colspan="4"><hr/></td></tr><tr class="thead"><td class="align_center" colspan="4">Corrosion inhibitor</td></tr><tr class="thead"><td class="align_left">Quantum chemical parameters</td><td class="align_center">PBTCA</td><td class="align_center">HEDP</td><td class="align_center">ATMP</td></tr><tr><td class="thead-hr" colspan="4"><hr/></td></tr><tr><td class="align_left"><i>E</i><sub>HOMO</sub> (eV)</td><td class="align_center">−7.5811</td><td class="align_center">−7.5321</td><td class="align_center">−6.4845</td></tr><tr><td class="align_left"><i>E</i><sub>LUMO</sub> (eV)</td><td class="align_center">−0.3320</td><td class="align_center">0.6857</td><td class="align_center">0.9960</td></tr><tr><td class="align_left">Δ<i>E</i> (eV)</td><td class="align_center">−7.2491</td><td class="align_center">−8.2178</td><td class="align_center">−7.4805</td></tr><tr><td class="align_left">Dipole moment (debye)</td><td class="align_center">3.7949</td><td class="align_center">5.7964</td><td class="align_center">12.0357</td></tr><tr><td class="align_left">Electron affinity (<i>A</i>)</td><td class="align_center">0.3320</td><td class="align_center">−0.6857</td><td class="align_center">−0.9960</td></tr><tr><td class="align_left">Electronegativity (<i>χ</i>)</td><td class="align_center">3.9566</td><td class="align_center">3.4232</td><td class="align_center">2.7443</td></tr><tr><td class="align_left">Hardness (<i>η</i>)</td><td class="align_center">3.6246</td><td class="align_center">4.1089</td><td class="align_center">3.7403</td></tr><tr><td class="align_left">Affinity index (<i>ω</i>)</td><td class="align_center">2.1595</td><td class="align_center">1.4260</td><td class="align_center">1.0068</td></tr><tr class="table-tr"><td colspan="4"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Quantum chemical parameters of the three organic phosphorus inhibitors at the B3LYP/6-31G (d, p) theoretical level.</div>

Advances in Materials Science and Engineering

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Table 3

Table 3: Organic Phosphorus Compounds as Inhibitors of Corrosion of Carbon Steel in Circulating Cooling Water: Weight Loss Method and Thermodynamic and Quantum Chemical Studies 

Table 3 | Organic Phosphorus Compounds as Inhibitors of Corrosion of Carbon Steel in Circulating Cooling Water: Weight Loss Method and Thermodynamic and Quantum Chemical Studies 