Synthesis, characterization and surface properties of amino-glycopolysiloxane

Block-copolymeric maltodextrin-based amphiphilic glycosilicones as surface-active systems

An efficient synthetic strategy that includes protection–modification–deprotection consequence was successfully developed to obtain novel water-soluble, amphiphilic, surface-active maltodextrin-based glycosilicones.

The Different Outcomes of Electrochemical Copolymerisation: 3-Hexylthiophene with Indole, Carbazole or Fluorene

Electrochemical polymerisation is reported to be a method for readily producing copolymers of various conjugated molecules. We employed this method for mixtures of indole, carbazole or fluorene with 3-hexylthiophene (HT), in order to obtain their soluble copolymers. Although polymer films were obtained, infrared (IR) and Raman investigations showed that instead of the expected linear copolymers, polyindole and polycarbazole N-substituted with HT, as well as a poly(3-hexylthiophene) (PHT)/polyfluorene blend were produced instead. Boron trifluoride diethyl etherate was also used in an attempt to promote copolymerisation, but the produced deposits were found to be highly degraded.

Poly(3-hexylthiophene) Grafting and Molecular Dilution: Study of a Class of Conjugated Graft Copolymers

A type of graft copolymer based on polysiloxane and regioregular poly(3-hexylthiophene) (P3HT) has been synthesised and its properties have been studied alongside those of its parent conjugated polymer-regioregular P3HT. Electrochemical analysis has revealed more significant changes in conformation of the copolymer film than was observed for P3HT. UV-Vis-NIR spectroelectrochemical investigation provided evidence of improved doping reversibility of the copolymer, despite its marginally increased band gap, as also confirmed by electroconductometric analysis. Evidence has been shown, indicating that polaron mobilities in both P3HT and the copolymer are higher than those of bipolaronic charge carriers, even though both systems exhibit standard doping/dedoping patterns. The grafted copolymer was tested in bulk heterojunction solar cells. Preliminary studies show a great potential of these polymers for application in photovoltaics. Power conversion efficiency of up to 2.46% was achieved despite the dilution of the P3HT chains in the copolymer.

Interface Activity and Thermodynamic Properties of Cardanol Polyoxyethylene Ether Carboxylates

A series of saturated cardanol polyoxyethylene ether carboxylates was synthesized using renewable saturated cardanol originating from Cashew Nut Shell Liquid as raw material. The structures were characterized by hydrogen nuclear magnetic resonance spectroscopy. The studies of their surface activity and interface activity were carried out to analyze the influence of the chemical structures of the series of cardanol surfactants on the adsorption and micellization. Results showed that saturated cardanol polyoxyethylene ether carboxylates had a good surface activity and interface activity, and the interface activities of the Gemini cardanol surfactants were better than those of the corresponding monomer cardanol surfactants. The critical micelle concentrations (CMC) of all investigated cardanol surfactants, obtained from surface tension measurements, were low in the order of 10−5 mol/L. The CMCs decreased and the oil-water interface tension for the same cardanol surfactants increased with the increase of the oxyethylene number. The process of micellization became easier with increasing the oxyethylene number. The ΔG θ m values of the Gemini cardanol surfactants were more negative than those of the corresponding monomer cardanol surfactants. The micellization for all cardanol surfactants was a spontaneous process and exhibited enthalpy-entropy compensation. The micellization of all the cardanol surfactants was entropy-driven.

Synthesis, Surface Activities, and Aggregation Behaviors of Butynediol-ethoxylate Modified Polysiloxanes

Five different butynediol-ethoxylate modified polysiloxanes (PSi-EO) were designed and synthesized via two-step reactions: the preparation of low-hydrogen containing silicone oil (LPMHS) by acid-catalyzed polymerization and the following hydrosilylation reaction with 1,4-bis(2-hydroxyethoxy)-2-butyne. The chemical composition of each product was confirmed by FT-IR, (1)H NMR, and (29)Si NMR. The surface activities and aggregation behaviors of PSi-EO surfactants in aqueous solution were studied systematically using surface tension, dynamic light scattering (DLS), transmission electron microscopy (TEM), and contact-angle methodologies. Relatively low critical aggregation concentration (15-34 mg·L(-1)) and surface tension (∼25 mN·m(-1)) were measured for PSi-EO aqueous solution. The rate of surface tension reduction increased both with increasing PSi-EO concentration and with increases in the proportion of hydrophilic moieties within the synthesized compounds. Furthermore, DLS and TEM studies revealed that PSi-EO self-assembled in aqueous solution to form spherical aggregates. Contact-angle measurements conducted upon low-energy paraffin film surfaces demonstrated that PSi-EO exhibited efficient spreading at concentrations above the critical aggregation concentration.