Reversible Photorheology in Solutions of Cetyltrimethylammonium Bromide, Salicylic Acid, and <i>trans</i>-2,4,4′-Trihydroxychalcone

Pereira, M. I. da Silva; Leal, Catarina Marques Mendes Almeida da Rosa; Parola, A. Jorge; Scheven, Ulrich M.

doi:10.1021/la102267d

Cited by 21 publications

(18 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, a reversible photorheological system was made using solutions of CTAB micelles with salicylic acid. 225 These systems form entangled wormlike micelles, depending on the concentration of the solutes. By adding trans-2,4,4 0 -trihydroxychalcone, the flavylium cation 4 0 ,7-dihydroxyflavylium is obtained after irradiation.…”

Section: Flavylium Network In Heterogeneous Mediamentioning

confidence: 99%

Chemistry and applications of flavylium compounds: a handful of colours

et al. 2012

View full text Add to dashboard Cite

Flavylium compounds are versatile molecules that comprise anthocyanins, the ubiquitous colorants used by Nature to confer colour to most flowers and fruits. They have found a wide range of applications in human technology, from the millenary colour paints described by the Roman architect Vitruvius, to their use as food additives, combining colour and antioxidant effects, and even as light absorbers in solar cells aiming at a greener solar energy conversion. Their rich complexity derives in part from their ability to switch between a variety of species (flavylium cations, neutral quinoidal bases, hemiketals and chalcones, and negatively charged phenolates) by means of external stimuli, such as pH, temperature and light. This critical review describes (i) the historical advancements in the understanding of the equilibria of their chemical reaction networks; (ii) their thermodynamics and kinetics; (iii) the mechanisms underlying their colour development, such as co-pigmentation and host-guest interactions; (iv) the photophysics and photochemistry that lead to photochromism; and (v) applications in solar cells, models for optical memories, photochromic soft materials such as ionic liquids and gels, and their properties in solid state materials (274 references).

show abstract

Section: Flavylium Network In Heterogeneous Mediamentioning

confidence: 99%

Chemistry and applications of flavylium compounds: a handful of colours

et al. 2012

View full text Add to dashboard Cite

show abstract

“…Scheven and coworkers 65 employed a multistate photoactive compound, 2,4,4 0 -trihydroxychalcone (Ct, Fig. 3c), to impart photorheological properties to aqueous solutions of weakly entangled WLMs formed by CTAB in the presence of salicylic acid (HSal).…”

Section: àmentioning

confidence: 99%

“…Based on the discussion above, we envision that many of these SWLMs systems have potential as vehicles for controlled and targeted delivery. Other useful triggers reported for smart WLMs include light, 43,49,[52][53][54][55][56][57][59][60][61][62][63][64][65][66] because of the possibility to direct it to specific body compartments. One could also envisage imparting responsiveness to chemical and biological stimuli, such as glucose concentration for the treatment of diabetes 5 or the presence of metabolites.…”

Section: Biomedicinementioning

confidence: 99%

Smart wormlike micelles

2013

View full text Add to dashboard Cite

A major scientific challenge of the past decade pertaining to the field of soft matter has been to craft 'adaptable' materials, inspired by nature, which can dynamically alter their structure and functionality on demand, in response to triggers produced by environmental changes. Amongst these, 'smart' surfactant wormlike micelles, responsive to external stimuli, are a particularly recent area of development, yet highly promising, given the versatility of the materials but simplicity of the design-relying on small amphiphilic molecules and their spontaneous self-assembly. The switching 'on' and 'off' of the micellar assembly structures has been reported using electrical, optical, thermal or pH triggers and is now envisaged for multiple stimuli. The structural changes, in turn, can induce major variations in the macroscopic characteristics, affecting properties such as viscosity and elasticity and sometimes even leading to a spontaneous and effective 'sol-gel' transition. These original smart materials based on wormlike micelles have been successfully used in the oil industry, and offer a significant potential in a wide range of other technological applications, including biomedicine, cleaning processes, drag reduction, template synthesis, to name but a few. This review will report results in this field published over the last few years, describe the potential and practical applications of stimuli-responsive wormlike micelles and point out future challenges.

show abstract

“…The binary system showed a viscoelastic response due to the formation of WLMs. After 100 min of UV irradiation, however, the CA molecules exhibited molecular photo-isomerization from transto cis-, which resulted in a change of WLMs into spherical micelles accompanied with drop in η 0 from 1.5 to 0.04 Pa s. Scheven and co-workers [22] employed a multi-state photo-active compound, 2,4,4′-trihydroxychalcone (Ct, Fig. 3.1c), to impart photo-rheological properties to aqueous solutions of weakly entangled WLMs formed by CTAB in the presence of salicylic acid (HSal).…”

Section: Uv/vis Isomerization Of a Light-respondermentioning

confidence: 99%

Light-responsive Wormlike Micelles

Feng¹,

Chu

Dreiss

2015

SpringerBriefs in Molecular Science

View full text Add to dashboard Cite

UV/Vis light as a trigger displays a set of advantages over other types of stimuli in terms of its "clean" character, low cost, and precise spatial localization, and for these reasons it has been widely exploited in the development of smart materials. Light-responsive wormlike micelles take advantage of light-induced cis-trans isomerization or dimerization of light-sensitive surfactants or additives containing a suitable chromophore. These changes alter the packing of surfactant molecules in the aggregates and drive micellar transitions between wormlike micelles and other structures, thus tuning the viscoelasticity. This chapter summarizes two types of strategies in manipulating light-sensitive wormlike micelleseither to incorporate light-sensitive additives into classical existing wormlike micellar solutions or to directly introduce light-sensitive functional moieties on the surfactant molecules. In both cases, the worms self-assemble or disassemble upon alternate UV/Vis light irradiation.Keywords Photo-switchable · Light-responsive · Wormlike micelles · Azobenzene · Cis-trans isomerization · Photo-rheology UV/Vis light as a trigger displays a set of benefits over other types of stimuli and thus has been widely exploited in the development of smart materials [1][2][3][4]. Light as a stimulus is relevant to many biological processes, in which optical signals are recorded and transduced as sophisticated biochemical events. In addition, in contrast to redox reagents, pH, stress, or salinity, light is an elegant and non-invasive trigger and can be operated in a clean environment, thus avoiding changes in the composition or thermodynamic conditions. It is a cheap and readily available trigger as a mild energy source. Finally, better than ultrasound and electricity, light can be directed at a precise spatial location; this is particularly valuable in nanoscience and nanotechnology and for medical applications.Light has been used as a trigger by exploiting dimerization, cis-trans isomerization, photo-scission, polymerization, or polarity changes in a range of systems [3]. However, quite obviously, not all reported light-sensitive surfactants

show abstract

Reversible Photorheology in Solutions of Cetyltrimethylammonium Bromide, Salicylic Acid, and trans-2,4,4′-Trihydroxychalcone

Cited by 21 publications

References 30 publications

Chemistry and applications of flavylium compounds: a handful of colours

Chemistry and applications of flavylium compounds: a handful of colours

Smart wormlike micelles

Light-responsive Wormlike Micelles

Contact Info

Product

Resources

About