Seminar

Polyoxyethylene alkylether carboxylic acids: fundamental studies on multifunctional surfactants

Time: 2:00 pm - 12:00 am

Date: 06/03/2018

Synopsis

Polyoxyethylene alkylether carboxylic acids are a highly versatile class of surfactants.

The molecule can be subdivided into three main parts: the lipophilic alkyl chain, which can vary in length and degree of insaturation; the polyoxyethylene block, and the terminal caborxylic acid, whose degree of ionization depends on solutions pH.

This class of surfactants combines the advantages of nonionic and ionic tensides. They tolerate hard water, respond to temperature, and their HLB values can be easily varied, but are water soluble at high temperature, and exhibit a charged headgroup at pH > 4.0. From a fundamental
science perspective, polyoxyethylene alkylether carboxylic acids are highly interesting building blocks in the colloidal playground. Given their high versatility, an incredible variety of responsive aggregates can be obtained when mixed with oppositely charged polymers, e.g., the biopolycation chitosan.

In this contribution, the basic physico-chemical properties of polyoxyethylene alkylether carboxylic acids will be presented and rationalized in term of simple but powerful concepts from colloidal chemistry. More complex self-assembled systems are obtained in mixture of polyoxyethylene alkylether carboxylic acids and chitosan, which strongly vary in structure, functionality, and field of application[13]. To conclude, we show an elegant way of separating pollutants from an aqueous solutions by exploiting the pH and temperature responsive properties of polyoxyethylene alkylether carboxylic acids[4-5].

References:
(1) Chiappisi, L.; Gradzielski, M. Househ. Pers. Care Today 2016, 11, 8–11.
(2) Chiappisi, L.; Prévost, S.; Grillo, I.; Gradzielski, M. Langmuir 2014, 30 (35),
10608–10616.
(3) Chiappisi, L.; Prévost, S.; Grillo, I.; Gradzielski, M. Langmuir 2014, 30 (7), 1778–1787.
(4) Schwarze, M.; Groß, M.; Moritz, M.; Buchner, G.; Kapitzki, L.; Chiappisi, L.; Gradzielski,
J. Memb. Sci. 2015, 478, 140–147.
(5) Schwarze, M.; Chiappisi, L.; Prévost, S.; Gradzielski, M. J. Colloid Interface Sci. 2014, 421, 184–190.

 

speakers

  • Leonardo Chiappisi Università di Berlino

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