Unveiling aggregation concentration in surfactants and ionic liquids using confocal Raman and hyper-Raman spectroscopies

IF 5.2 2区化学 Q2 CHEMISTRY, PHYSICAL

Journal of Molecular Liquids Pub Date : 2025-09-29 DOI:10.1016/j.molliq.2025.128622

Krishanu Bandyopadhyay , Abhineet Verma , Neeraj Singh Rawat , Surajit Maity , Hirotsugu Hiramatsu , Satyen Saha

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引用次数: 0

Abstract

A key characteristic property of Ionic liquids (ILs) is their tendency to form nano-scale aggregates, that sets them apart from other liquid materials. While methods like conductance and surface tension measurements are commonly used to determine aggregation of surfactants, they often come with significant limitations when employed for ILs. Although the aggregation behavior of ILs has been studied for the last decade, accurately determining their critical ionic liquid aggregation concentration (CILAC, first proposed by Saha and coworkers, ChemistrySelect, 2019, 4, 49–58) remains a challenging task. Here in this study, a Raman signature band of networked water molecules is used to study the aggregation of IL in a 20 % ethanol in water binary mixture. This study examines how the hydrogen bonding interactions influence the aggregation of ILs such as [C₁C_nmim][Cl] (with n = 4, 6, 8, and 10) and surfactants like CTAB, SDS, and TX-100. This report introduces Raman and Hyper Raman spectroscopy as a novel method for determining aggregation concentration, where traditional techniques like the conductivity measurement method fails.

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利用共聚焦拉曼和超拉曼光谱揭示表面活性剂和离子液体中的聚集浓度

离子液体（ILs）的一个关键特性是它们倾向于形成纳米级聚集体，这使它们与其他液体材料区别开来。虽然电导和表面张力测量等方法通常用于确定表面活性剂的聚集，但当用于il时，它们通常存在显着的局限性。尽管过去十年来人们一直在研究离子液体的聚集行为，但准确确定它们的临界离子液体聚集浓度（CILAC，由Saha和同事首次提出，chemistry, 2019, 4,49 - 58）仍然是一项具有挑战性的任务。在本研究中，网络水分子的拉曼特征带被用于研究IL在20%乙醇-水二元混合物中的聚集。本研究考察了氢键相互作用如何影响il(如[C1Cnmim][Cl] （n = 4,6,8和10）和表面活性剂（如CTAB， SDS和TX-100）的聚集。本报告介绍了拉曼和超拉曼光谱作为一种新的方法来确定聚集浓度，而传统的技术，如电导率测量方法是失败的。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

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来源期刊

Journal of Molecular Liquids 化学-物理：原子、分子和化学物理

CiteScore

10.30

自引率

16.70%

发文量

2597

审稿时长

78 days

期刊介绍： The journal includes papers in the following areas: – Simple organic liquids and mixtures – Ionic liquids – Surfactant solutions (including micelles and vesicles) and liquid interfaces – Colloidal solutions and nanoparticles – Thermotropic and lyotropic liquid crystals – Ferrofluids – Water, aqueous solutions and other hydrogen-bonded liquids – Lubricants, polymer solutions and melts – Molten metals and salts – Phase transitions and critical phenomena in liquids and confined fluids – Self assembly in complex liquids.– Biomolecules in solution The emphasis is on the molecular (or microscopic) understanding of particular liquids or liquid systems, especially concerning structure, dynamics and intermolecular forces. The experimental techniques used may include: – Conventional spectroscopy (mid-IR and far-IR, Raman, NMR, etc.) – Non-linear optics and time resolved spectroscopy (psec, fsec, asec, ISRS, etc.) – Light scattering (Rayleigh, Brillouin, PCS, etc.) – Dielectric relaxation – X-ray and neutron scattering and diffraction. Experimental studies, computer simulations (MD or MC) and analytical theory will be considered for publication; papers just reporting experimental results that do not contribute to the understanding of the fundamentals of molecular and ionic liquids will not be accepted. Only papers of a non-routine nature and advancing the field will be considered for publication.