<p>This paper presents an investigation into the methyl iodide (CH<InlineEquation ID="IEq1"> <EquationSource Format="TEX">$_3$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>3</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>I) retention capacity of a synergistic system combining mesoporous silica and polyethyleneimine (PEI). The optimized PEI-loaded SBA-15 sample exhibited an impressive CH<InlineEquation ID="IEq2"> <EquationSource Format="TEX">$_3$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>3</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>I retention of up to 610 mg/g at 130 <InlineEquation ID="IEq3"> <EquationSource Format="TEX">$^\circ$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mrow /> <mo>∘</mo> </mmultiscripts> </math></EquationSource> </InlineEquation>C, and a decontamination factor of more than 3000 for radioactive methyl iodide in a 50 mm adsorption bed. The distinct reactivity modes of CH<InlineEquation ID="IEq4"> <EquationSource Format="TEX">$_3$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>3</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>I with various amine types in PEI were elucidated through spectroscopic analyses, and density functional theory simulations. In particular, CH<InlineEquation ID="IEq5"> <EquationSource Format="TEX">$_3$</EquationSource> <EquationSource Format="MATHML"><math> <mmultiscripts> <mrow /> <mn>3</mn> <mrow /> </mmultiscripts> </math></EquationSource> </InlineEquation>I preferentially formed chemical bonds with primary amine sites through N-methylation reactions, and the electron transfer between N and methyl iodide promoted the formation of <InlineEquation ID="IEq6"> <EquationSource Format="TEX">${\hbox {I}_{3}^-}$</EquationSource> <EquationSource Format="MATHML"><math> <msubsup> <mtext>I</mtext> <mrow> <mn>3</mn> </mrow> <mo>-</mo> </msubsup> </math></EquationSource> </InlineEquation> and <InlineEquation ID="IEq7"> <EquationSource Format="TEX">${\hbox {I}_{5}^-}$</EquationSource> <EquationSource Format="MATHML"><math> <msubsup> <mtext>I</mtext> <mrow> <mn>5</mn> </mrow> <mo>-</mo> </msubsup> </math></EquationSource> </InlineEquation> species. This synergistic system shows great promise for applications in the fields of radioiodine capture and nuclear waste management.</p>

Retention performance of polyethyleneimine-loaded mesoporous silica-based materials for methyl iodide

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发表日期：

2026年7月27日

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Jian-Lu Pei,
Xue-Fei Liang,
Yong-Guo Li,
Xin Li,
Ze-Xiang Chen,
Shu-Wei Liang,
Xin Chen,
Hai-Jiao Xie

摘要

This paper presents an investigation into the methyl iodide (CH $_3$ $_{3}$ I) retention capacity of a synergistic system combining mesoporous silica and polyethyleneimine (PEI). The optimized PEI-loaded SBA-15 sample exhibited an impressive CH $_3$ $_{3}$ I retention of up to 610 mg/g at 130 $^\circ$ $^{\circ}$ C, and a decontamination factor of more than 3000 for radioactive methyl iodide in a 50 mm adsorption bed. The distinct reactivity modes of CH $_3$ $_{3}$ I with various amine types in PEI were elucidated through spectroscopic analyses, and density functional theory simulations. In particular, CH $_3$ $_{3}$ I preferentially formed chemical bonds with primary amine sites through N-methylation reactions, and the electron transfer between N and methyl iodide promoted the formation of ${\hbox {I}_{3}^-}$ $I_{3}^{-}$ and ${\hbox {I}_{5}^-}$ $I_{5}^{-}$ species. This synergistic system shows great promise for applications in the fields of radioiodine capture and nuclear waste management.