| 1. |
- Boujemaoui, Assya, et al.
(författare)
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Preparation and characterization of functionalized cellulose nanocrystals
- 2015
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Ingår i: Carbohydrate Polymers. - : Elsevier. - 0144-8617 .- 1879-1344. ; 115, s. 457-464
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Tidskriftsartikel (refereegranskat)abstract
- In this work, a series of functional nanocrystals (F-CNCs) was successfully produced by an efficient preparation method, combining acid hydrolysis and Fischer esterification with various organic acids. Functionalities such as ATRP initiators, double bonds, triple bonds, and thiols could be incorporated on CNCs. Surface modification was confirmed by FT-IR, XPS, and elemental analysis. Physical properties of FC-NCs were assessed by AFM, XRD and TGA. Moreover, ATRP initiator functionalized CNCs were utilized to graft poly(methyl methacrylate) via ATRP, thiol functionalized CNCs were reacted with Ellman's reagent to determine the thiol content and dye disperse red 13 was attached to alkyne functionalized CNCs to estimate the propiolate content. The herein presented method is a highly versatile and straightforward procedure for the preparation of F-CNCs which is believed to be a better alternative for the commonly utilized, extensive, multistep, and time consuming post functionalization methods.
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| 2. |
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| 3. |
- Mongkhontreerat, Surinthra, 1986-
(författare)
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Advanced Functional Thin Films and Networks towards Biological Applications
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Functional polymeric scaffolds have been employed in biological applications as several utilities, from nano-sized drug delivery systems to concrete implants. The progression in biological fields essentially relies on finding an appropriate material to fulfil the critical requirements for various types of applications with great potential for tuning functionality and mechanical properties. Therefore, the generation of new materials in extensive libraries is desirable for researchers. In this thesis, two main varieties of functional scaffolds have been constructed; these include i) periodic structure isoporous membranes and ii) three dimension (3D) crosslinked networks with programmable functionalities and mechanical properties. In the first case, a library of linear dendritic (LD) block copolymers was synthesised from biocompatible 2,2-bis(methylol)propionic acid (bis-MPA) dendrons and 2- hydroxyethyl methacrylate (HEMA) derivatives. These materials were successfully employed for the fabrication of isoporous membranes via the facile Breath Figure (BF) method. The dendritic periphery end groups control the manipulation of film morphology, as well as introduction of desired functionalities, either pre- or post- film formation. The introduction of azide functional group along the polymer backbone allows crosslinking reaction, which enhances the stability of the isoporous films. The stability towards temperature was improved from around its glass transition temperature (Tg) to 400 °C after crosslinking; simultaneously the porosity is maintained after immersion in the whole range of pH (1-14). These materials show great potential use as high performance isoporous membranes in futuristic applications such as micro-reactors, sensors and cell patterning platforms. In the second case, the facile fabrication of functional networks employs off-stoichiometric crosslinking, which resulted in residual reactive functional groups after film formation and networks with different crosslinking density. This straightforward off-stoichiometric concept is applied with commercially available materials and well-controlled dendritic-linear-dendritic (DLD) hybrid polymers, generating functional networks with different properties from high stiffness film to soft hydrogels. The network post-modification can be performed topologically and throughout the scaffold. Several crosslinking chemistries were employed for construction of hydrogels from DLD hybrid polymers. The Copper(I) Catalysed Azide-Alkyne Cycloaddition (CuAAC) click reaction results in hydrogels with higher compressive modulus compared to other hydrogels constructed from thiol-ene, thiol-yne and amine-N-hydroxysuccinimide (NHS) esters coupling methods with similar building blocks. These functional crosslinked networks are suitable for numerous applications including fabrication of microfluidic devices, cell culture platforms and bone adhesives.
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| 4. |
- Mongkhontreerat, Surinthra, et al.
(författare)
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Beyond state of the art honeycomb membranes : High performance ordered arrays from multi-programmable linear-dendritic block copolymers
- 2015
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Ingår i: Advanced Functional Materials. - : Wiley. - 1616-301X .- 1616-3028. ; 25:30
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Tidskriftsartikel (refereegranskat)abstract
- A new generation of honeycomb membranes is herein described from a novel library of multipurpose linear-dendritic block copolymers. These are accomplished by combining atom transfer radical polymerization together with dendrimer chemistry and click reactions. The resulted amorphous block copolymers, with T-g between 30 and 40 degrees C, display three important functions, i.e., pore generating aromatic groups, crosslinking azides, and multiple dendritic functional groups. All block copolymers enable the successful fabrication of honeycomb membranes through the facile breath figure method. The peripheral dendritic functionality is found to influence the porous morphologies from closed pored structure with pore size of 1.12 mu m(2) to open pore structure with pore size 10.26 mu m(2). Facile UV crosslinking of the azides yields membranes with highly durable structural integrity. Upon crosslinking, the pH and thermal stability are extended beyond the noncrosslinked membranes in which the porous integrity is maintained up to 400 degrees C and pH 1-14. Taking into account the straightforward and cost-efficient strategy to generate ordered, functional, and structurally stable honeycomb membranes on various solid substrates, it is apparent that these multipurpose block copolymers may unlock future applications including use as molds for soft lithography.
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| 5. |
- Mongkhontreerat, Surinthra, et al.
(författare)
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Dendritic hydrogels : From exploring various crosslinking chemistries to introducing functions and naturally abundant resources
- 2015
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Ingår i: Journal of Polymer Science Part A. - : Wiley. - 0887-624X .- 1099-0518. ; 53:21, s. 2431-2439
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Tidskriftsartikel (refereegranskat)abstract
- Dendritic hydrogels from dendritic-linear-dendritic (DLD) block copolymers based on PEG and bis-MPA dendrons were constructed via UV-initiated thiol-ene, thiol-yne, CuAAC, and amine-NHS crosslinking chemistries. Stoichiometric ratio manipulations, prior to film formation, resulted in functional hydrogels with tuneable compressive moduli. The highest gel fractions for all networks were obtained at off-stoichiometric ratios with surplus of DLDs. Finally, sustainable networks were fabricated by amalgamating DLD, naturally abundant cellulose nanocrystal, and protein-based bovine serum albumin.
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| 6. |
- Mongkhontreerat, Surinthra, et al.
(författare)
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Functional porous membranes from amorphous linear dendritic polyester hybrids
- 2015
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Ingår i: Polymer Chemistry. - : Royal Society of Chemistry (RSC). - 1759-9954 .- 1759-9962. ; 6:13, s. 2390-2395
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Tidskriftsartikel (refereegranskat)abstract
- By combining ATRP, dendrimer chemistry and 'click' reactions, a library of novel linear dendritic block copolymers (hybrids) was successfully synthesized. The isolated polymers displayed hydrophilic alkyne groups and T-g's ranging from 14 degrees C to 67 degrees C. A T-g threshold of 39 degrees C was found necessary for straightforward porous membrane fabrication via the breath figure method. Exploiting the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction, a robust and benign protocol was identified enabling surface functionalization under aqueous conditions. Such manipulations included the introduction of fluorescent rhodamine for thorough assessment by confocal fluorescence microscopy as well as polyethylene glycol chains or perfluorinated groups for tuning the membrane wettability. Finally, with the initial indication of being nontoxic to human dermal fibroblasts (hDF) and osteoblast-like MG63, the porous membranes can potentially find use in the field of controlled cell culture such as patterning of cell growth.
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| 7. |
- Mongkhontreerat, Surinthra, et al.
(författare)
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UV initiated thiol-ene chemistry : A facile and modular synthetic methodology for the construction of functional 3D networks with tunable properties
- 2013
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Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 1:44, s. 13732-13737
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Tidskriftsartikel (refereegranskat)abstract
- A facile methodology for the fabrication of functional crosslinked three dimensional (3D) networks has herein been explored via the benign and UV initiated thiol-ene coupling (TEC) chemistry. The careful selection of monomers or polymers and their feed ratio resulted in straightforward design of organic, inorganic and hydrogel networks with readily available alkenes or thiol functional groups. All crosslinked networks were fabricated within 1 second of UV exposure at wavelengths of 320-390 nm and generally exhibited excellent gel fractions around 90%. By introducing off-stoichiometric thiol and ene (OSTE) monomer feed ratios the window of mechanical properties could be manipulated. For the organic triazine system, the Young's modulus was altered from 780 MPa at an equimolar monomer ratio to soft 106 kPa for 2.5 equiv. with excess of thiol compared to enes. Postfunctionalizations with hydrophilic polyethylene glycols or acrylic acid and hydrophobic heneicosafluorododecyl acrylate were explored for the manipulation of functional networks. In this case, the rigid networks with excess of thiols were used as model substrates of which the initial contact angle (CA) of 60°was decreased to 43°by the introduction of acrylic acid and increased to 140°by successful attachment of fluorinated molecules. Finally, amalgamating micropatterning strategy with simple postfunctionalizations of hydrophobic groups resulted in superhydrophobic rigid surfaces with a CA of 173°.
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