Assembly and Properties of SWCNTs Porous Films at Interface and Supramolecular Functional Materials Based on 2,2′:6′,2″-terpyridyl Derivatives
Supervisor:hao jing cheng
Chemistry is a science of transformation and evolution Ever since the artificial synthesis of urea in 1828,synthetic chemistry based on covalent bond has achieved splendid accomplishments via ingenious designing.With the advances in study on macrocyclic molecular synthesis,non-covalent interactions have been noticed,contributing to the birth of a "molecular social scienc e"——supramolecular chemistry,This interdisciplinary field focuses on the physical,chemical and biological characters of molecular ecology,which is far more complicated than individual molecular behaviorsThe main research missions of supramolecular chemistry contain molecular recognition(host-guest interaction between molecules or ions),self-assembly of macrocyclic organic molecules,supramolecular reaction and transfer in biological organic-inorganic system,crystal engineering,interface template self-assembly and molecular deviceThis dissertation mainly concentrates on overcoming two challenges of the interface template self-assembly and responsive molecular device.(1)Due to high surface energy of the single walled carbon nanotubes(SWCNTs),they tend to aggregate in organic solution and inhibit the formation of SWCNTs honeycomb-patterned filn with ordered arrays.To overcome this difficulty,a phase transfer method combined with cationic surfactant is employed to achieve the homodisperse of SWCNTs in casting solution.The morphologic control and electrochemistry performances of the fabricated porous films are investigated,respectively.This work provides new avenues for the preparation of highly ordered functional carbon materials and is also envisaged to find applications in antibacterial material and catalytic chemistry(2)Many works have been developed to fabricate responsive 2,2′:6′,2″-terpyridyl derivatives with different coordinated ions.However,terpyridyl derivatives bonded with photoresponsive group(such as azobenzene)are rarely reported.To make up for the blank of this field,a series of terpyridyl derivatives with different structures are synthesized(TPY-1 to TPY-5).Functionalized materials are fabricated based on these organic molecules.This work is expected to broaden the applications of 2,2′:6′,2″-terpyridyl derivatives in colorimetric probe and fluorescent material.Each chapter of this paper is introduced as follows:Chapter I.Introduction.Chapter I mainly covers the basic concepts of self-assembly,supramolecular chemistry,honeycomb-patterned films and 2,2′:6′2″－terpyridyl ramification.The history and diversiform applications of 2,2′:6′,2″-terpyridyl and organic fluorescent materials are concluded.Chapter Ⅱ.Micro meter-sized porous films based on the electrostatic interaction between carboxylic single walled carbon nanotubes(SWCNTs)and dimethyl dioctadecylammonium bromide(DODMABr)are fabricated through a breath figure method.The influence factors of films’ morphology such as the properties of organic solvents and concentrations of DODMABr are studied.An one step ion-exchange process is employed to remove the long-chain cationic ammonium away from the films.The antibacterial activity and electric conductivity of obtained pure SWCNTs honeycomb-patterned films are measured.Constant voltage dipulse is utilized to apply SWCNTs honeycomb films for the patterning of Ag nanoparticles.The catalytic application of the decorated membranes is investigated.Chapter III.Synthesis and design of a series of photoresponsive 2,2′:6′,2″-terpyridyl derivatives are listed.The synthetic procedures and characterizations are concluded.Chapter IV Test paper based on TPY-2 has been developed for the detection of pH values within alkaline range.A Br(?)nsted acid-base type reaction results in the deprotonation of the sensing molecule when combining with OH-in aqueous-organic mixed solvents.After absorbing onto filter paper and wiping off the solvent,the colorimetric sensor suffers a stepwise color change from faint yellow to crimson when being exposed to increasing concentrations of OH-from 7 to 14.This febricated alkaline pH test paper exhibits excellent reversibility and reusability by repeatedly water scrubbing and can be utilized as a specific substrate for inkless writing.Chapter V A novel ultraviolet responsive fluorescent material(BTC-1)based on aggregates transformation is prepared by the coordination of TPY-3 and EuCI3·6H2O.Photo-isomeric azobenzene groups are introduced into the long chain BTC-1 to control the aggregation’s topological structure in methanol When exposed to 365 nm UV radiation the emission intensity of the fluorescent solution keeps continuously increasing and the emission wavelength exhibits appreciably red shift.Affected by the trans-cis isomerization of azobenzene,the microstructure of the aggregation suffers a prominent transformation from nanosphere to micron sheet.The tight accumulation of the fluorophores is speculated to be the dominant factor of its novel responsive photoluninescence property.