Ceraulo Leopoldo, Giorgi Gianluca, Liveri Vincenzo Trco, Bongiorno David, Indelicato Serena, Di Gaudio Francesca, Indelicato Sergio
Dipartimento di Scienze e Tecnologie Molecolari e Biomolecolari, Università degli Studi di Palermo, Via Archirafi 32, I-90123, Palermo, Italy.
Eur J Mass Spectrom (Chichester). 2011;17(6):525-41. doi: 10.1255/ejms.1158.
In contrast with the enormous amount of literature produced during many decades in the field of surfactant aggregation in liquid, liquid crystalline and solid phases, only a few investigations concerning surfactant self- assembling in the gas phase as charged aggregates have been carried out until now. This lack of interest is disappointing in view of the remarkable theoretical and practical importance of the inherent knowledge. The absence of surfactant-solvent interactions makes it easier to study the role of surfactant-surfactant forces in determining their peculiar self-assembling features as well as the ability of these assemblies to incorporate selected solubilizate molecules. Thus, the study of gas-phase surfactant and surfactant-solubilizate aggregates is a research subject which has exciting potential, including mass and energy transport in the atmosphere, origin of life and simulation of supramolecular aggregation in interstellar space. On the other hand, the structural and dynamic properties of surfactant aggregates in the gas phase could be exploited in a number of interesting applications such as atmospheric cleaning agents, transport and protection of pulmonary drugs or biomolecules and as nanoreactors for specialized chemical reactions in confined space. Spectrometric techniques, together with molecular dynamics simulations, have been the principal investigative tools in this field and appearto be particularly suited to gaining fundamental information on the structure and stability of surfactant-based supramolecular aggregates, charge state effects, entrapment of solubilizate molecules, preferential solubilization sites and chemical reactions localized in a single organized aggregate. The main aim of this review is to present the actual state of the art in this novel and exciting research field underlining the knowledge acquired up to now as well as the aspects needing a more deep understanding. Moreover, intriguing departures of the behavior of surfactant solutions under electrospray ionization conditions from that of ionic, polar and apolar analytes will be discussed.
与在液相、液晶相和固相领域数十年间产生的大量文献相比，到目前为止，关于表面活性剂在气相中作为带电聚集体进行自组装的研究仅有少数几项。鉴于这一内在知识具有显著的理论和实际重要性，这种缺乏关注令人失望。表面活性剂与溶剂间相互作用的缺失使得研究表面活性剂 - 表面活性剂作用力在决定其独特自组装特征以及这些聚集体纳入特定增溶分子能力方面的作用变得更容易。因此，气相中表面活性剂和表面活性剂 - 增溶物聚集体的研究是一个具有令人兴奋潜力的研究课题，包括大气中的质量和能量传输、生命起源以及星际空间中超分子聚集的模拟。另一方面，气相中表面活性剂聚集体的结构和动力学性质可用于许多有趣的应用，如大气清洁剂、肺部药物或生物分子的运输与保护，以及作为受限空间中特定化学反应的纳米反应器。光谱技术与分子动力学模拟一起，一直是该领域的主要研究工具，似乎特别适合获取关于基于表面活性剂的超分子聚集体的结构和稳定性、电荷状态效应、增溶分子的包埋、优先增溶位点以及单个有序聚集体中发生的化学反应等基础信息。本综述的主要目的是呈现这个新颖且令人兴奋的研究领域的当前技术水平，强调迄今所获得的知识以及需要更深入理解的方面。此外，还将讨论在电喷雾电离条件下表面活性剂溶液行为与离子、极性和非极性分析物行为的有趣差异。
