Héloïse Thérien-Aubin

Memorial University of Newfoundland · Department of Chemistry

Superparamagnetism exists only in nanocrystals, and to endow micro/macro-materials with superparamagnetism, superparamagnetic nanoparticles have to be assembled into complex materials. Most techniques currently used to produce such assemblies are inefficient in terms of time and material. Herein, we used evaporation-guided assembly to produce super...

Bio-orthogonal reactions have become an essential tool to prepare biomaterials, for example, in the synthesis of nanocarriers bio-orthogonal chemistry allows circumventing common obstacles related to the encapsulation of delicate payload or the occurrence of uncontrolled side reactions, which significantly limit the range of potential payloads to e...

Grafting polymer chains on the surface of nanoparticles (NPs) is a strategy used to control the interaction between the NPs and their environment. The fate of the resulting particles in a given environment is strongly influenced by the solvent–polymer interaction. The solvent quality affects the behavior, conformation, and dynamics of the grafted p...

Strategies for corrosion protection are required to prolong the life-span of metallic structures used by the construction, aerospace, and transport industries. Currently, there are no coatings that can provide at the same time information about the corrosion status of the coated metal and protect the metal against corrosive species and mechanical d...

The combination of plasmonic nanoparticles with semiconductor photocatalysts is a good strategy for synthesizing highly efficient photocatalysts. Such binary nanoparticles have demonstrated enhanced catalytic activity in comparison to either plasmonic catalysts or semiconductor catalysts. However, problematic recovery and limited long-term colloida...

A new straight forward approach to create nanoporous polymer membranes with well defined average pore diameters is presented. The method is based on fast mechanical deformation of highly entangled polymer films at high temperatures and a subsequent quench far below the glass transition temperature Tg. The process is first designed generally by simu...

The inclusion of sulfur in polymer materials is becoming an excellent strategy to exploit the large feedstock of elemental sulfur produced as wastes by the oil industry. However, the resulting...

Childhood mortality represents a major issue with 5. 3 million worldwide deaths of children under 5 years of age in 2019. Approximately half of those deaths can be attributed to easily preventable, infectious diseases. Currently approved neonatal vaccines are typically effective only after multiple doses leaving infants especially vulnerable during...

Amongst colloidal gels, those designed by the assembly of anisotropic colloidal particles tend to form fibrillar gels and are attracting interest as artificial cell growth environments since they have a structure reminiscent of biological extracellular matrices. Their properties can be tuned by controlling the size, shape, and rigidity of the nanop...

Thiol-ene polymerization is a powerful synthetic platform for the preparation of a variety of polymer materials but is often plagued by the formation of low molecular weight polymers. This is...

The relative motion of two surfaces in direct contact results in friction and wear. This affects every moving surface, contributing to a quarter of the worldwide energy consumption. The addition of lubricant can reduce friction by separating the surfaces, making more energy-efficient systems. Lubricants are composed of a base oil and a series of ad...

Biomacromolecular therapeutic agents, particularly proteins, antigens, enzymes, and nucleic acids are emerging as powerful candidates for the treatment of various diseases and the development of the recent vaccine based on mRNA highlights the enormous potential of this class of drugs for future medical applications. However, biomacromolecular thera...

Nanocapsules are an excellent platform for the delivery of macromolecular payloads such as proteins, nucleic acids or polyprodrugs, since they can both protect the sensitive cargo and target its delivery to the desired site of action. However, the release of macromolecules from nanocapsules remains a challenge due to their restricted diffusion thro...

Triggering the release of encapsulated cargos using mechanical stress acting on a nanocarrier is a strategy with potential applications from drug delivery to self-healing coatings. The mechanically triggered release of encapsulated molecules can be controlled by tuning the mechanical properties of the nanocapsules, which are strongly linked to the...

In order to respond to the growing demand for radiation‐curable waterborne products like hydrogels or inks, there is a need for water‐soluble radical photoinitiators exhibiting absorption in the near UV to visible range. Herein the synthesis of a novel type‐I diphenylphosphine oxide photoinitiator bearing a 2,6‐dimethyl‐4‐dimethylaminobenzoyl group...

Responsive nanogel systems are interesting for the drug delivery of bioactive molecules due to their high stability in aqueous media. The development of nanogels that are able to respond to biochemical cues and compatible with the encapsulation and the release of large and sensitive payloads remains challenging. Here, multistimuli-responsive nanoge...

The precise control of nanostructure and surface atomic arrangement can be used to tune the electrocatalytic properties of materials and improve their performance. Unfortunately, the long-term structural stability of electrocatalysts with complex nanoscale morphology, a necessary requirement for industrial implementation, often remains elusive. Her...

Polymers containing sulfur centers with high oxidation states in the main chain, polysulfoxide and polysulfone, display desirable properties such as thermomechanical and chemical stability. To circumvent their challenging direct synthesis, methods based on the oxidation of a parent polysulfide have been developed but are plagued by uncontrolled rea...

Nanoreactors offer a great platform for the onsite generation of functional products. However, the production of the desired compound is often limited by either the availability of the reagents or their diffusion across the nanoreactor shell. To overcome this issue, we synthesized self-sustaining nanoreactors carrying the required reagents with the...

The versatile design of stimuli‐responsive microparticles embedding valuable biomolecules has great potential in a variety of engineering fields, such as sensors, actuators, drug delivery, and catalysis. Here, results are reported on thermoresponsive core–gap–shell (TCGS) microcapsules made of poly(N‐isopropylacrylamide) (PNIPAm), which encapsulate...

Two-photon polymerization stereolithographic three-dimensional (3D) printing is used for manufacturing a variety of structures ranging from microdevices to refractive optics. Incorporation of nanoparticles in 3D printing offers huge potential to create even more functional nanocomposite structures. However, this is difficult to achieve since the ag...

We study the effect of entanglements on the glass transition of high molecular weight polymers, by the comparison of single-chain nanoparticles (SCNPs) and equilibrated melts of high-molecular weight polystyrene of identical molecular weight. SCNPs were prepared by electrospraying technique and characterized using scanning electron microscopy and a...

The behavior of nanogels in suspension can be dramatically affected by the grafting of a canopy of end-tethered polymer chains. The architecture of the interfacial layer, defined by the grafting density and length of the polymer chains, is a crucial parameter in defining the conformation and influencing the dynamics of the grafted chains. However,...

Soft polymer nanoparticles can be functionalised with end-tethered polymer chains to control their solvent compatibility and stability. Controlling and understanding the behaviour of such functionalised latex suspensions is critical for their comprehensive applications. To investigate the effect of the nanoparticles architecture on their rheologica...

The design of surface-modified functional nanoparticles (NPs) is used to control the properties of the NPs and the NP/environment interactions. The efficient control of the final behavior of the NPs demands a comprehensive understanding of the resulting system. This is particularly challenging for systems with an architecture of the type polymer co...

A reversible polymer photoacid with a thermal on/off switch at physiological temperature able to trigger a large pH modulation of its environment is prepared. Light is used to control the acidity of the solution. Additionally, the temperature could be used to modulate the photoacid efficiency, practically turning on and off the ability of the polym...

Electrospun polymer mats are widely used in tissue engineering, wearable electronics, and water purification. However, in many environments the polymer nanofibers prepared by electrospinning suffer from biofouling during long-term usage, resulting in persistent infections and device damage. Herein, we describe the fabrication of polymer mats with C...

Non-toxic alkanoylcholine soaps (nACh) were synthesized from choline and fatty acids with numbers of carbons n equal to 12, 14, 16 and 18, the latter including both saturated and 9-cis unsaturated alkanoyl chains. Coupling of nACh with hyaluronic acid (HyA) rendered comb-like ionic complexes nACh·HyA that were non-water soluble. The complexes were...

Due to its nondestructive and noninvasive nature, its versatility, and its ease of implementation, NMR imaging has imposed itself as a technique well suited to study pharmaceutical tablets for controlled release of active ingredients. NMR imaging has been used for over two decades to study the pharmaceutical formulation. It is possible to obtain cr...

The influence of the presence of small molecules and nanoparticles on the mechanism of amyloid fibril formation has attracted attention because amyloid protein fibrils are associated with degenerative diseases. Here, we studied the interaction between gold nanoparticles (AuNPs) and a model protein (lysozyme). Both the formation of amyloid fibrils i...

Polymer nanocarriers are used as transport modules in the design of the next generation of drug delivery technology. However, the applicability of nanocarrier-based technology depends strongly on our ability to precisely control and reproduce their synthesis on a large scale because their properties and performances are strongly dependent on their...

Growth of three-dimensional cancer spheroids (CSs) in man-made hydrogels mimicking natural extracellular matrix is an important and challenging task. Herein, we report on a supramolecular temperature-responsive hydrogel designed for the growth and subsequent release of CSs. A filamentous hydrogel was formed at 37 °C from an aqueous suspension of ce...

Growth of three-dimensional cancer spheroids (CSs) in man-made hydrogels mimicking natural extracellular matrix is an important and challenging task. Herein, we report on a supramolecular temperature-responsive hydrogel designed for the growth and subsequent release of CSs. A filamentous hydrogel was formed at 37 °C from an aqueous suspension of ce...

Natural extracellular matrices often have a filamentous nature, however, only a limited number of artificial extracellular matrices have been designed from nanofibrillar building blocks. Here we report the preparation of temperature-responsive nanofibrillar hydrogels from rod-shaped cellulose nanocrystals (CNCs) functionalized with a copolymer of N...

The organization of nanoparticles in constrained geometries is an area of fundamental and practical importance. Spherical confinement of nanocolloids leads to new modes of packing, self-assembly, phase separation and relaxation of colloidal liquids; however, it remains an unexplored area of research for colloidal liquid crystals. Here we report the...

Patterning of colloidal particles with chemically or topographically distinct surface domains (patches) has attracted intense research interest. Surface-patterned particles act as colloidal analogues of atoms and molecules, serve as model systems in studies of phase transitions in liquid systems, behave as 'colloidal surfactants' and function as te...

Linear assemblies of nanoparticles show promising applications due to their collective electronic, optical and magnetic properties. Rational design and controllable organization of nanoparticles in one-dimensional structures can strongly benefit from the marked similarity between conventional step-growth polymerization reactions and directional ste...

Microscale technologies offer the capability to generate in vitro artificial cellular microenvironments that recapitulate the spatial, biochemical, and biophysical characteristics of the native extracellular matrices and enable systematic, quantitative, and high-throughput studies of cell fate in their respective environments. We developed a microf...

Due to its nondestructive and noninvasive nature, its versatility, and its ease of implementation, NMR imaging has imposed itself as a technique well suited to study pharmaceutical tablets for controlled release of active ingredients. NMR imaging has been used for over two decades to study the pharmaceutical formulation. It is possible to obtain cr...

Thin film composite (TFC) polyamide membranes are extensively used as selective barriers in reverse osmosis processes. The major challenge faced with TFC membranes is significant fouling on the surface, which restricts the overall purification performance. To address the fouling problem, we developed novel fouling-resistant surface coatings via pol...

Nanoparticle (NP) dispersions are extensively used for the producing nanocomposite materials. Optimization of formulations of NP dispersions is a time- and labor-consuming process that can benefit from high-throughput preparation of composite materials, followed by studies of their structure–property relationships. This paper describes a microfluid...

Nanofibrillar hydrogels are an important class of biomaterials, with applications as catalytic scaffolds, artificial extracellular matrixes, coatings and drug delivery materials. In the present work, we report the results of a comprehensive study of nanofibrillar hydrogels formed by cellulose nanocrystals (CNCs) in the presence of cations with vari...

Rational design of the programmable soft matter requires understanding of the effect of complex metric on shape transformations of thin non-Euclidean sheets. In the present work, we explored experimentally and using simulations how simultaneous or consecutive application of two orthogonal perturbations to thin patterned stimuli-responsive hydrogel...

. Co-assembly of nanoparticles with different size- and shape-dependent properties is a promising approach to the design and fabrication of functional materials and devices. This paper reports the results of a detailed investigation of the formation and properties of free-stranding composite films formed by the co-assembly of cellulose nanocrystals...

Thin film composite polyamide membranes are extensively used as selective barriers in reverse osmosis processes. The major challenge faced with TFC membranes is significant fouling on the surface, which restricts the overall purification performance. In order to address the fouling problem, we developed novel fouling resistant surface coatings via...

The entropically driven coassembly of nanorods (cellulose nanocrystals, CNCs) and nanospheres (dye-labeled spherical latex nanoparticles, NPs) was studied in aqueous suspensions and in solid films. In mixed CNC-latex suspensions, phase separation into an isotropic latex-NP-rich and a chiral nematic CNC-rich phase took place; the latter contained a...

We report the structural and optical properties of composite films formed from mixed suspensions of cellulose nanocrystals (CNCs) and fluorescent latex nanoparticles (NPs). We explored the effect of the variation in NP concentration, size, surface charge, and glass transition temperature on film structure and properties. The chiral nematic order, t...

Nanofibrillar supramolecular hydrogels are hierarchical structures formed by physical association of high-aspect-ratio nanoscale building blocks, each containing many molecules held together via supramolecular interactions. Nanofibrils have diameters in the range of tens to hundreds of nanometers, and their lengths can exceed micrometers. The drivi...

Solution-based linear self-assembly of metal nanoparticles offers a powerful strategy for creating plasmonic polymers, which, so far, have been formed from spherical nanoparticles and cylindrical nanorods. Here, we report linear solution-based self-assembly of metal nanocubes (NCs), examine the structural characteristics of the NC chains and demons...

To develop understanding on the nature of complex, spatiotemporal interactions between cells and the extracellular matrix (ECM), artificial ECMs formed from hydrogels with a particular spectrum of properties are being developed at a rapid pace. We report microfluidic generation of monodispersed composite agarose-gelatin microgel particles that can...

Thin-film composite (TFC) polyamide reverse osmosis (RO) membranes are prone to biofouling due to their inherent physicochemical surface properties. In order to address the biofouling problem, we have developed novel surface coatings functionalized with biocidal silver nanoparticles (AgNPs) and antifouling polymer brushes via polyelectrolyte layer-...

The resemblance between colloidal and molecular polymerization reactions is very useful in fundamental studies of polymerization reactions, as well as in the development of new nanoscale systems with desired properties. Future applications of colloidal polymers will require nanoparticle ensembles with a high degree of complexity that can be realize...

Polymeric reverse osmosis membranes were modified with antifouling polymer brushes through a ‘layer by layer’ (LBL) mediated method. Based on pure physical electrostatic interaction, the attachment of LBL films did not alter separation performance of the membranes. In addition, the incorporation of an LBL film also helped to amplify the number of p...

Significance Self-assembly of nanoparticles in polymer-like chains bears a strong similarity to polymerization reactions, in which monomer units are brought together by directional noncovalent interactions. Based on this similarity, the molecular concepts of polymer chemistry can be applied to achieve controllable nanoparticle assembly. On the othe...

Assembly of nanoscale materials from nanoparticle (NP) building blocks relies on our understanding of multiple nanoscale forces acting between NPs. These forces may compete with each other and yield distinct stimuli-responsive self-assembled nanostructures. Here, we report structural transitions between linear chains and globular assemblies of char...

Although Nature has always been a common source of inspiration in the development of artificial materials, only recently has the ability of man-made materials to produce complex three-dimensional (3D) structures from two-dimensional sheets been explored. Here we present a new approach to the self-shaping of soft matter that mimics fibrous plant tis...

Soft materials undergoing shape transformations in response to changes in ambient environment have potential applica-tions in tissue engineering, robotics and biosensing. Generally, stimulus-responsive materials acquire two stable shapes corresponding to the "on" and "off" states of the external trigger. Here, we report a simple, yet versatile appr...

By using microfluidics, we generated micellar nanofibrillar microgels from solutions of worm-like micelles of poly(N-isopropyl acrylamide)block-polystyrene. The microgels were formed under physiological conditions (pH = 7.4, 37 degrees C) and rapidly dissociated upon cooling to 25-27 degrees C, thereby enabling cell encapsulation and release for fu...

Thin-film composite (TFC) polyamide reverse osmosis (RO) membranes are prone to biofouling due to its inherent physicochemical surface properties. In order to address the bio-fouling problem, we have developed novel surface coatings via polyelectrolyte layer-by-layer (LBL) self-assembly, functionalized with biocidal nanoparticles and antifouling po...

Plasmonic polymers present an interesting concept that builds on the analogy between molecular polymers and linear chains of strongly interacting metal nanoparticles. Ensemble-averaged optical properties of plasmonic polymers are strongly influenced by their structure. In the present work, we formed plasmonic polymers using solution-based assembly...

A major problem to be addressed with thin composite films used in processes such as coatings or water purification is the biofouling of the surface. To address this problem in a model system, functionalized polyaramide membranes containing an atom transfer radical polymerization (ATRP) initiator were synthesized as a versatile approach to easily mo...

NMR imaging is a non-destructive and non-invasive technique especially well suited to investigate the kinetics of water uptake, swelling and erosion of pharmaceutical tablets used for drug delivery. Polysaccharides such as high amylose starch, cellulose derivatives and chitosan have been used as excipients in the tablets for the controlled release...