Inhibition of API 5L X52 Pipeline Steel Corrosion in Acidic Medium by Gemini Surfactants: Electrochemical Evaluation and Computational Study

<table class="fixed-width table-group" id="tab5"><tr><td><table class="table"><colgroup><col style="width:6.85em"/><col style="width:11.31em"/><col style="width:5.74em"/><col style="width:6.29em"/><col style="width:6.29em"/></colgroup><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr class="thead"><td class="align_left">Surfactant</td><td class="align_center">Linear correlation<br/> coefficient, r<sup>2</sup></td><td class="align_center">Slope</td><td class="align_center"><svg height="11.6836pt" id="M26" style="vertical-align:-3.29562pt" version="1.1" viewbox="-0.0498162 -8.38798 21.7745 11.6836" width="21.7745pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M667 0V28C619 34 599 43 546 100C496 154 386 277 311 372C378 440 449 512 488 547C551 605 575 615 650 622V650H410V622L433 619C478 614 479 604 449 568C404 513 337 443 282 390C254 364 234 350 212 345V520C212 609 222 616 299 622V650H41V622C120 616 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21 526 26V56ZM367 88C342 69 306 54 271 54C207 54 133 111 133 229C133 373 219 409 264 409C301 409 342 394 367 359V88Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,17.676,3.132)"><path d="M327 325C324 350 312 408 304 433C283 442 256 451 213 451C120 451 59 391 59 320C59 243 125 210 188 181C237 158 266 136 266 93C266 52 231 24 195 24C134 24 93 81 74 148L42 143C42 106 51 37 59 23C78 8 125 -12 177 -12C257 -12 345 35 345 127C345 198 292 234 216 264C171 283 131 305 131 348C131 387 156 416 195 416C243 416 277 378 297 317L327 325Z"></path></g></svg> x <svg height="11.7978pt" id="M27" style="vertical-align:-0.2063999pt" version="1.1" viewbox="-0.0498162 -11.5914 23.1538 11.7978" width="23.1538pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M384 0V27C293 34 287 42 287 114V635C232 613 172 594 109 583V559L157 557C201 555 205 550 205 499V114C205 42 199 34 109 27V0H384Z"></path></g><g transform="matrix(.013,0,0,-0.013,6.24,0)"><path d="M241 635C89 635 35 457 35 312C35 153 89 -12 240 -12C390 -12 443 166 443 312C443 466 390 635 241 635ZM238 602C329 602 354 454 354 312C354 172 330 22 240 22C152 22 124 173 124 313S148 602 238 602Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,12.527,-5.741)"><path d="M556 236V289H56V236H556Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,18.087,-5.741)"><path d="M290 377C321 398 342 415 358 430C378 450 389 473 389 502C389 578 329 635 238 635H237C184 635 137 610 109 578L64 515L88 493C112 529 154 573 208 573S303 542 303 482C303 409 233 370 141 341L149 308C165 313 190 319 215 319C272 319 341 283 341 193C342 98 292 43 222 43C163 43 122 72 96 94C88 101 79 100 70 94C61 87 47 73 46 60C44 47 48 37 62 23C76 10 118 -12 165 -12C238 -12 430 62 430 223C430 297 379 359 290 375V377Z"></path></g></svg>  <br/>(l. mol<sup>−1</sup>)</td><td class="align_center">ΔG<br/>kJ. <svg height="12.0392pt" id="M28" style="vertical-align:-0.2454996pt" version="1.1" viewbox="-0.0498162 -11.7937 31.1266 12.0392" width="31.1266pt" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"><g transform="matrix(.013,0,0,-0.013,0,0)"><path d="M797 0V26C739 32 732 36 732 103V296C732 394 682 449 605 449C576 449 550 437 529 423C504 407 475 389 446 366C425 418 382 449 334 449C303 449 279 437 253 421C222 403 201 385 180 371V452C135 432 85 419 41 411V388C99 379 102 374 102 310V103C102 38 93 32 27 26V0H238V26C189 32 180 38 180 103V338C210 363 250 390 289 390C351 390 377 348 377 275V103C377 37 368 32 306 26V0H520V26C465 32 456 38 456 101V296C456 314 455 326 453 338C491 369 529 390 565 390C628 390 653 345 653 274V107C653 36 642 32 583 26V0H797Z"></path></g><g transform="matrix(.013,0,0,-0.013,10.595,0)"><path d="M257 449C165 449 37 374 37 209C37 98 119 -12 256 -12C355 -12 473 65 473 226C473 349 381 449 257 449ZM244 416C333 416 380 320 380 204C380 67 329 21 267 21C184 21 130 115 130 241C130 354 184 416 244 416Z"></path></g><g transform="matrix(.013,0,0,-0.013,17.134,0)"><path d="M238 0V26C174 32 166 38 166 104V712C132 700 70 683 18 677V653C81 647 87 645 87 577V104C87 38 78 32 15 26V0H238Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,20.5,-5.944)"><path d="M556 236V289H56V236H556Z"></path></g><g transform="matrix(.0091,0,0,-0.0091,26.06,-5.944)"><path d="M389 0V32C297 38 291 46 291 118V635C234 613 175 595 109 583V556L161 554C203 552 207 547 207 497V118C207 46 201 38 110 32V0H389Z"></path></g></svg></td></tr><tr><td class="thead-hr" colspan="5"><hr/></td></tr><tr><td class="align_left">A312</td><td class="align_center">0.9997</td><td class="align_center">1.034</td><td class="align_center">251.130</td><td class="align_center">-40.57</td></tr><tr><td class="align_left" colspan="5"><hr/></td></tr><tr><td class="align_left">A314</td><td class="align_center">0.9996</td><td class="align_center">1.049</td><td class="align_center">163.941</td><td class="align_center">-39.69</td></tr><tr><td class="align_left" colspan="5"><hr/></td></tr><tr><td class="align_left">A316</td><td class="align_center">0.9993</td><td class="align_center">1.083</td><td class="align_center">128.336</td><td class="align_center">-39.09</td></tr><tr class="table-tr"><td colspan="5"><hr class="tbody-hr"/></td></tr></table></td></tr></table>

<div>Adsorption parameters of synthesized inhibitors on the steel surface.</div>

International Journal of Corrosion

tab5

Table 5

Table 5: Inhibition of API 5L X52 Pipeline Steel Corrosion in Acidic Medium by Gemini Surfactants: Electrochemical Evaluation and Computational Study 

Table 5 | Inhibition of API 5L X52 Pipeline Steel Corrosion in Acidic Medium by Gemini Surfactants: Electrochemical Evaluation and Computational Study 