Interplay of Light and Self-Assembly in Functional Soft Materials - From Photo-Controlled to Photonic Structures

Mikko Poutanen

Interplay of Light and Self-Assembly in Functional Soft Materials - From Photo-Controlled to Photonic Structures

Julkaisun otsikon käännös: Valon ja itsejärjestymisen vuorovuorovaikutus pehmeissä toiminnallisissa materiaaleissa

Mikko Poutanen

Tutkimustuotos: Doctoral Thesis › Collection of Articles

Abstrakti

Valoon reagoivia itsejärjestyviä rakenteita käytetään laajasti toiminnallisissa pehmeissä materiaaleissa. Erityisen suurta mielenkiintoa ovat herättäneet isomeroituvien atsobentseenimolekyylien ja supramolekulaaristen rakenteiden tai nestekiteiden yhdistelmät. Nämä mahdollistavat rakenteiden etäohjauksen ja molekyylitason valovasteen vahvistamisen makroskooppiselle tasolle. Toisaalta lohkopolymeerien ja kolloidien suuremman mittaluokan itsejärjestyvät rakenteet voivat ohjata valon kulkua ja muodostaa fotonisia rakenteita. Tämä väitöskirja keskittyy valon ja itsejärjestymisen vuorovaikutus valoon reagoivissa ja fotonisissa materiaaleissa. Julkaisussa I tutkitaan itsejärjestymisen vaikutusta atsobentseenin isomerisaatiokinetiikkaan vetysitoutuvissa polymeerikomplekseissa. Termisen isomerisaation näytetään kiihtyvän hydroksiatsobenseenikomplekseissa konsentraation kasvaessa. Pienellä konsentraatiolla näytteet ovat epäjärjestyneitä, kun taas suuren konsentraation näytteet järjestyvät lamellaarisiin smektisiin rakenteisiin. Vertailu suuren konsentraation vastaavaan epäjärjestyneeseen kompleksiin osoittaa erityisesti molekyylien järjestyksestä ja suuntautumisesta syntyvän keskinäisen vuorovaikutuksen olevan tärkeä isomerisaatiokinetiikan kannalta. Julkaisussa II hydroksiatsobentseenikomplekseja ja niiden termistä isomerisaatiokinetiikkaa hyödynnetään vetysitoutuvien kaasujen, erityisesti suhteellisen kosteuden, mittaamisessa. Komplekseista tutkitaan isomerisaationopeuden riippuvuutta vesi- ja etanolihöyryistä, ja erityisesti ilman suhteellisen kosteuden suhteen sen näytetään olevan eksponentiaalinen, hyvin toistettava ja säädettävissä. Työssä demonstroidaan muutoksen hyödyntäminen sensorina. Isomerisaatiokinetiikan käyttö sensorisovelluksissa mahdollistaa uusia käyttökohteita supramolekulaarisille atsobentseenikomplekseille. Julkaisussa III tutkitaan atsobentseeniä sisältäviä halogeenisidottuja supramolekulaarisia nestekiteitä. Stilbatsolien ja fluorinoitujen atsobentseenimolekyylien näytetään muodostavan systemaattisesti nestekiteitä, jotka perustuvan molekyylien väliseen vahvasti suuntariippuvaan halogeenisidokseen. Valolla luotua järjestys-epäjärjestys-faasitransitiota tutkitaan tarkemmin, muun muassa siihen tarvittavan cis-isomeerin osuus määritetään. Julkaisussa IV kehitetään yleispätevää menetelmää luoda fotonisia nesteitä ja 3D fotonikiteitä käyttämällä lohkopolymeerimisellejä, joilla on kvaternisoituva polymeerikuori. Tämä edellyttää hyvin kapeaa kokojaukaumaa ja voimakkaasti laajentuvaa polymeerikuorta. Misellien näytetään kiteytyvän yli millimetrin kokoisiin fotonikiteisiin. Lisäksi fotonikiteillä näytetään olevan erityisen kapeat heijastuspiikit ja kiteitä muokkaamalla heijastusaallonpituutta voidaan säätää koko näkyvän valon alueella. Fotonikiteet ovat lisäksi uudelleenmuotoutuvia ja niitä voidaan kontrolloida muuttamalla konsentraatiota ja suolapitoisuutta.

Julkaisun otsikon käännös	Valon ja itsejärjestymisen vuorovuorovaikutus pehmeissä toiminnallisissa materiaaleissa
Alkuperäiskieli	Englanti
Pätevyys	Tohtorintutkinto
Myöntävä instituutio	Aalto-yliopisto
Valvoja/neuvonantaja	Ikkala, Olli, Vastuuprofessori Priimägi, Arri, Ohjaaja
Kustantaja	Aalto University
Painoksen ISBN	978-952-60-8165-6
Sähköinen ISBN	978-952-60-8166-3
Tila	Julkaistu - 2018
OKM-julkaisutyyppi	G5 Artikkeliväitöskirja

Tutkimusalat

itsejärjestyminen
valoon reagoiva
atsobentseeni
lohkopolymeeri
miselli
fotonikide

Pääsy asiakirjaan

http://urn.fi/URN:ISBN:978-952-60-8166-3Lisenssi: Määrittelemätön

OtaNano
Anna Rissanen (Manager)
Aalto-yliopisto
Laitteistot/tilat: Facility
OtaNano Nanomikroskopiakeskus
Jani Seitsonen (Manager)
OtaNano
Laitteistot/tilat: Facility

Siteeraa tätä

@phdthesis{5af0ea12d77b457a8044edeaeec73363,

title = "Interplay of Light and Self-Assembly in Functional Soft Materials - From Photo-Controlled to Photonic Structures",

abstract = "Photo-responsive molecules in combination with self-assembled structures have been widely used in devising soft functional materials. Especially photoisomerizable azobenzene molecules incorporated into supramolecular structures or liquid crystalline systems, which enable the control of order and amplifying the molecular photo-response to a macroscopic scale, have triggered great interest. On the other hand, larger-scale self-assemblies based on, e.g., block copolymer or colloidal structures may significantly modify light propagation in the self-assembled materials, leading to photonic properties and structural colors. The main focus of this thesis lies in this intriguing interplay between light and self-assembly shown by these photo-controlled and photonic systems. Publication I studies the effect of self-assembly on the photoresponse and isomerization kinetics of azobenzenes in hydrogen-bonded polymeric complexes. These complexes of hydroxyazobenzene derivatives are used to demonstrate a drastic increase in the thermal cis-trans isomerization rate upon a transition from a disordered low-azobenzene-content state to a high-concentration state with lamellar smectic-like order. Comparison between disordered and ordered high-concentration states shows that the former exhibits significantly slower kinetics, pinpointing the importance of cooperativity created by the molecular order and alignment. In Publication II the amorphous hydrogen-bonded complexes of hydroxyazobenzenes are used to demonstrate how thermal isomerization kinetics of azobenzenes can be exploited in optical sensing of hydrogen-bonding gas vapors, especially relative humidity. The thermal isomerization of different complexes is shown to exhibit exponential changes with huge dynamic range, high reproducibility and tunability in the presence of water and ethanol. The use as a sensor is further demonstrated. Using isomerization kinetics for sensing is potentially opening new avenues for using azobenzene molecules and their supramolecular complexes in practical applications. Publication III investigates halogen-bonded supramolecular liquid crystals containing azobenzene moieties. These complexes of stilbazole and fluorinated azobenzene derivatives are shown to systematically form liquid crystals held together by the highly directional halogen bonding. The photoisomerization-induced LC-isotropic transition is studied in detail, and the cis-isomer content required for the transition is determined. In Publication IV a generic method is developed for using the self-assembly of block copolymer micelles with a quaternizable block to create photonic fluids and 3D photonic crystals. For this, reaching micelles with narrow size distributions and highly swollen coronae is critical. The observed crystallization demonstrates that these qualities are reached. The micelles spontaneously assemble in up to millimeter-sized crystal lattices. In addition, the photonic crystals result in extremely narrow reflection peaks ranging over the visible region, have high tunability through changes in concentration and salinity, and form reversibly.",

keywords = "self-assembly, photo-response, azobenene, block copolymer, micelle, photonic crystal, itsej{\"a}rjestyminen, valoon reagoiva, atsobentseeni, lohkopolymeeri, miselli, fotonikide, self-assembly, photo-response, azobenene, block copolymer, micelle, photonic crystal",

author = "Mikko Poutanen",

year = "2018",

language = "English",

isbn = "978-952-60-8165-6",

series = "Aalto University publication series DOCTORAL DISSERTATIONS",

publisher = "Aalto University",

number = "169",

address = "Finland",

school = "Aalto University",

}

TY - BOOK

T1 - Interplay of Light and Self-Assembly in Functional Soft Materials - From Photo-Controlled to Photonic Structures

AU - Poutanen, Mikko

PY - 2018

Y1 - 2018

N2 - Photo-responsive molecules in combination with self-assembled structures have been widely used in devising soft functional materials. Especially photoisomerizable azobenzene molecules incorporated into supramolecular structures or liquid crystalline systems, which enable the control of order and amplifying the molecular photo-response to a macroscopic scale, have triggered great interest. On the other hand, larger-scale self-assemblies based on, e.g., block copolymer or colloidal structures may significantly modify light propagation in the self-assembled materials, leading to photonic properties and structural colors. The main focus of this thesis lies in this intriguing interplay between light and self-assembly shown by these photo-controlled and photonic systems. Publication I studies the effect of self-assembly on the photoresponse and isomerization kinetics of azobenzenes in hydrogen-bonded polymeric complexes. These complexes of hydroxyazobenzene derivatives are used to demonstrate a drastic increase in the thermal cis-trans isomerization rate upon a transition from a disordered low-azobenzene-content state to a high-concentration state with lamellar smectic-like order. Comparison between disordered and ordered high-concentration states shows that the former exhibits significantly slower kinetics, pinpointing the importance of cooperativity created by the molecular order and alignment. In Publication II the amorphous hydrogen-bonded complexes of hydroxyazobenzenes are used to demonstrate how thermal isomerization kinetics of azobenzenes can be exploited in optical sensing of hydrogen-bonding gas vapors, especially relative humidity. The thermal isomerization of different complexes is shown to exhibit exponential changes with huge dynamic range, high reproducibility and tunability in the presence of water and ethanol. The use as a sensor is further demonstrated. Using isomerization kinetics for sensing is potentially opening new avenues for using azobenzene molecules and their supramolecular complexes in practical applications. Publication III investigates halogen-bonded supramolecular liquid crystals containing azobenzene moieties. These complexes of stilbazole and fluorinated azobenzene derivatives are shown to systematically form liquid crystals held together by the highly directional halogen bonding. The photoisomerization-induced LC-isotropic transition is studied in detail, and the cis-isomer content required for the transition is determined. In Publication IV a generic method is developed for using the self-assembly of block copolymer micelles with a quaternizable block to create photonic fluids and 3D photonic crystals. For this, reaching micelles with narrow size distributions and highly swollen coronae is critical. The observed crystallization demonstrates that these qualities are reached. The micelles spontaneously assemble in up to millimeter-sized crystal lattices. In addition, the photonic crystals result in extremely narrow reflection peaks ranging over the visible region, have high tunability through changes in concentration and salinity, and form reversibly.

AB - Photo-responsive molecules in combination with self-assembled structures have been widely used in devising soft functional materials. Especially photoisomerizable azobenzene molecules incorporated into supramolecular structures or liquid crystalline systems, which enable the control of order and amplifying the molecular photo-response to a macroscopic scale, have triggered great interest. On the other hand, larger-scale self-assemblies based on, e.g., block copolymer or colloidal structures may significantly modify light propagation in the self-assembled materials, leading to photonic properties and structural colors. The main focus of this thesis lies in this intriguing interplay between light and self-assembly shown by these photo-controlled and photonic systems. Publication I studies the effect of self-assembly on the photoresponse and isomerization kinetics of azobenzenes in hydrogen-bonded polymeric complexes. These complexes of hydroxyazobenzene derivatives are used to demonstrate a drastic increase in the thermal cis-trans isomerization rate upon a transition from a disordered low-azobenzene-content state to a high-concentration state with lamellar smectic-like order. Comparison between disordered and ordered high-concentration states shows that the former exhibits significantly slower kinetics, pinpointing the importance of cooperativity created by the molecular order and alignment. In Publication II the amorphous hydrogen-bonded complexes of hydroxyazobenzenes are used to demonstrate how thermal isomerization kinetics of azobenzenes can be exploited in optical sensing of hydrogen-bonding gas vapors, especially relative humidity. The thermal isomerization of different complexes is shown to exhibit exponential changes with huge dynamic range, high reproducibility and tunability in the presence of water and ethanol. The use as a sensor is further demonstrated. Using isomerization kinetics for sensing is potentially opening new avenues for using azobenzene molecules and their supramolecular complexes in practical applications. Publication III investigates halogen-bonded supramolecular liquid crystals containing azobenzene moieties. These complexes of stilbazole and fluorinated azobenzene derivatives are shown to systematically form liquid crystals held together by the highly directional halogen bonding. The photoisomerization-induced LC-isotropic transition is studied in detail, and the cis-isomer content required for the transition is determined. In Publication IV a generic method is developed for using the self-assembly of block copolymer micelles with a quaternizable block to create photonic fluids and 3D photonic crystals. For this, reaching micelles with narrow size distributions and highly swollen coronae is critical. The observed crystallization demonstrates that these qualities are reached. The micelles spontaneously assemble in up to millimeter-sized crystal lattices. In addition, the photonic crystals result in extremely narrow reflection peaks ranging over the visible region, have high tunability through changes in concentration and salinity, and form reversibly.

KW - self-assembly

KW - photo-response

KW - azobenene

KW - block copolymer

KW - micelle

KW - photonic crystal

KW - itsejärjestyminen

KW - valoon reagoiva

KW - atsobentseeni

KW - lohkopolymeeri

KW - miselli

KW - fotonikide

KW - self-assembly

KW - photo-response

KW - azobenene

KW - block copolymer

KW - micelle

KW - photonic crystal

M3 - Doctoral Thesis

SN - 978-952-60-8165-6

T3 - Aalto University publication series DOCTORAL DISSERTATIONS

PB - Aalto University

ER -

Interplay of Light and Self-Assembly in Functional Soft Materials - From Photo-Controlled to Photonic Structures

Abstrakti

Tutkimusalat

Pääsy asiakirjaan

Sormenjälki

Laitteet

OtaNano

OtaNano Nanomikroskopiakeskus

Siteeraa tätä