PROCESS FOR FUNCTIONALIZING A SURFACE OF A SOLID SUPPORT WITH NANO- OR MICROPARTICLES

Abstract

In surface functionalization of a surface with nano- or microparticles, a process is for functionalizing a surface of a solid support with nano- or microparticles. Polymers include polymerized amine-functionalized monomer units. The polymers are used to functionalize a solid support with nano- or microparticles. The resulting nano- or microparticles functionalized polymers includes polymerized amine-functionalized monomer units.

Claims

1. A process for functionalizing a surface of a solid support with nano- or microparticles, said process comprising: i) Reacting at least one monomer with at least one amine, to obtain an amine-functionalized monomer, said at least one monomer being a mono, bi-, tri- or tetrafunctional monomer wherein said functions are chosen from acrylate, methacrylate, epoxy and vinyl groups, said vinyl groups being exclusive of acrylate or methacrylate groups, at least one of said functions being an acrylate, methacrylate or epoxy group, said at least one amine being chosen from: amines of the following formula (I) NR.sub.1R.sub.2R.sub.3, wherein R.sub.1, R.sub.2 and R.sub.3 are each independently chosen from H and C.sub.1-C.sub.8 linear or branched alkyl groups substituted by a group R.sub.4 chosen from —OH, —SH and aromatic groups, provided that when R.sub.1, R.sub.2 and R.sub.3 are other than H, then at least one of R.sub.1, R.sub.2 and R.sub.3 is a C.sub.1-C.sub.8 linear or branched alkyl group substituted by at least one —OH or —SH group; aminoacids; and hexamethylenetetramine; ii) bringing at least said surface into contact with a composition or comprising: the functionalized monomer obtained in step i); a polymerization initiator; a solvent; and a polymerization inhibitor; iii) polymerization of the composition of step ii) in contact with the surface to functionalize, to obtain a surface coated with an amine-functionalized polymer; and iv) contacting at least the surface coated with an amine-functionalized polymer obtained in step iii) with nano- or microparticles functionalized with negatively charged ligands, at a pH equal or less than (pKa of the amine +1), to obtain a solid support with a surface functionalized with nano- or microparticles.

2. The process according to claim 1, wherein the nano- or microparticles have a size ranging from 1 nm to 100 μm.

3. The process according to claim 1, wherein the nano- or microparticles are constituted of or comprise a material chosen from metals, metal oxides, and graphene oxide, diamonds, polymers, and semiconductors.

4. The process according to claim 1, wherein the solid support is chosen from the group consisting of conducting, semiconducting or insulating materials.

5. The process according to claim 1, wherein the at least one monomer is: a mono, bi-, tri- or tetrafunctional monomer wherein said functions are acrylate groups, or a mono, bi-, tri- or tetrafunctional monomer wherein said functions are epoxy groups.

6. The process according to claim 1, wherein the at least one monomer is chosen from pentaerythriol triacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate, di(trimethylolpropane) tetraacrylate, triethylene glycol dimethacrylate, 1,6-Hexanediol diacrylate (HDODA), aromatic urethane triacrylate, for example EBECRYL® 204, bisphenol A epoxy diacrylate, for example Ebecryl® 3708 or EBECRYL® 605, bisphenol A diglycidyl ether.

7. The process according to claim 1, wherein in the at least one amine of formula (I): R.sub.1, R.sub.2 and R.sub.3 are each independently chosen from C.sub.1-C.sub.8 linear or branched alkyl groups, at least one of these groups being substituted by one —OH group; R.sub.1 is H, R.sub.2 and R.sub.3 are each independently chosen from C.sub.1-C.sub.8 linear or branched alkyl groups, at least one of these groups being substituted by one —OH group; or R.sub.1 and R.sub.2 are H, and R.sub.3 is chosen from C.sub.1-C.sub.8 linear or branched alkyl groups substituted by one —OH group.

8. The process according to claim 1, wherein the at least one amine of formula (I) is chosen from methyl diethanolamine, ethyldiethanolamine, 2-amino-2-méthyl-1-propanol, diethanolamine, diethyl amine, n-propylamine, n-butylamine, n-pentylamine, methanol amine, ethanolamine, n-propanol amine, n-butanol amine, n-pentanol amine, diethyl amine, dipropyl amine, dibutyl amine, dipentyl amine, dimethanol amine, diethanol amine, dipropanol amine, dibutanol amine, dipentanol amine, triethanolamine, and derivatives thereof.

9. The process according to claim 1, wherein the reaction of step i) is performed at a temperature ranging from 20 to 70° C. and/or for 1 second to 2 weeks.

10. The process according to claim 1, wherein the composition is brought into contact with the surface during step ii) by dipping, spincoating, sprinkling, projection, transfer, drawdown application coating or spraying.

11. The process according to claim 1, wherein the polymerization of step ii) is a radiation induced polymerization or a thermally induced polymerization.

12. A nano- or microparticles functionalized polymer comprising polymerized amine-functionalized monomer units, said monomer units being mono, bi-, tri- or tetrafunctional monomer units, wherein said functions are chosen from acrylate, methacrylate, epoxy and vinyl groups, said vinyl groups being exclusive of acrylate or methacrylate groups, at least one of said functions being an acrylate, methacrylate or epoxy group, said monomer units being functionalized by at least one amine, said at least one amine being: of the following formula (I) NR.sub.1R.sub.2R.sub.3, wherein R.sub.1, R.sub.2 and R.sub.3 are each independently chosen from H and C.sub.1-C.sub.8 linear or branched alkyl groups substituted by a group R.sub.4 chosen from —OH, —SH and aromatic groups, provided that when R.sub.1, R.sub.2 and R.sub.3 are other than H, then at least one of R.sub.1, R.sub.2 and R.sub.3 is a C.sub.1-C.sub.8 linear or branched alkyl group substituted by at least one —OH or —SH group, an aminoacid; or hexamethylenetetramine; said nano- or microparticles being functionalized with ligands bearing negatively charged ligands.

13. A kit with one or more containers containing under an inert atmosphere or noble gas a polymer comprising polymerized amine-functionalized monomer units, said monomer units being mono, bi-, tri- or tetrafunctional monomer units, wherein said functions are chosen from acrylate, methacrylate, epoxy and vinyl groups, said vinyl groups being exclusive of acrylate or methacrylate groups, at least one of said functions being an acrylate, methacrylate or epoxy group, said monomer units being functionalized by at least one amine, said at least one amine being: of the following formula (I) NR.sub.1R.sub.2R.sub.3, wherein R.sub.1, R.sub.2 and R.sub.3 are each independently chosen from H and C.sub.1-C.sub.8 linear or branched alkyl groups substituted by a group R.sub.4 chosen from —OH, —SH and aromatic groups, provided that when R.sub.1, R.sub.2 and R.sub.3 are other H, then at least one of R.sub.1, R.sub.2 and R.sub.3 is a C.sub.1-C.sub.8 linear or branched alkyl group substituted by at least one —OH or —SH group; an aminoacid; or hexamethylenetetramine.

14. (canceled)

Description

DESCRIPTION OF THE DRAWINGS

[0138] FIG. 1 shows by SEM the polymer line with functionalization (FIG. 1A) according to example 1 and without (FIG. 1B) after immersion in citrate capped GNPs colloid for 5 hours.

[0139] FIG. 2 corresponds to SEM images of GNPs immobilization on: 3D Helices (FIG. 2A) and woodpile (FIG. 2B); flat square microstructure (FIG. 2C) and continuous lines (FIG. 2D).

[0140] FIG. 3 shows SEM images of woodpiles different periods: (FIG. 3A) 0.6 (FIG. 3B) 0.8 (FIG. 3C) 1.0 and (FIG. 3D) 1.5 μm; inner layers (FIG. 3E) and bottom layers (FIG. 3F) after immersion in GNPs colloid. Scale bar is 1 μm.

[0141] FIG. 4 shows: (A) the extinction spectra of 2D flat square microstructure (1) and 3D woodpile of period 1.5 μm (2) microstructures immobilized by GNPs; (B) Raman spectrum of 10.sup.−1 M BPE molecule on glass substrate (1), SERS spectra of 10.sup.−5 M BPE molecule on the 2D (2) and 3D (3) structures.

EXAMPLES

Example 1: Preparation of a GNP Functionalized Polymer Comprising Polymerized Amine-Functionalized Monomer Units According to the Invention

Preparation of the Amine-Functionalized Monomer

[0142] 73.5% in weight of PETA monomer was functionalized by 15% in weight of methyldiethanol amine (MDEA), according to oxa-Michael addition reaction. This reaction is performed at a temperature ranging from 20 to 70° C. and/or for 1 second to 1 hour, for example at a temperature 40° C. and for 15 minutes.

Preparation of the Amine-Functionalized Polymer

[0143] 1.5% of Irg-819 photoinitiator and 10% of MEHQ inhibitor were added to the amine-functionalized monomer as described above in order to initiate the polymerization process. One drop from the prepared mixture was deposited on a glass substrate (22×22 mm) to write the desired microstructure by two-photon polymerization (TPP or 2PP) using Nanoscribe.

[0144] The photopolymerization process was performed by Nanoscribe Photonic Professional system with a femtosecond laser at λ=780 nm focused by a 100×/1.3 NA oil immersion objective.

[0145] After the accomplishing of the photo-polymerization process, lift-off was done in acetone and isopropanol in order to remove the un-polymerized materials.

Functionalization with Gold Nanoparticles (GNP)

[0146] A colloidal suspension of citrate capped GNP (of about 40-50 nm of diameter) was prepared by the Turkevish's procedure as described by Frens et al. (Nature, vol. 241, no. 105, p. 20, 1973).

[0147] The amine-functionalized polymer obtained in the previous step was immersed for about 5 hours in said GNPs solution at a pH of 3.8.

Results

[0148] The scanning electron microscopy (SEM) images in FIG. 1 show clearly the selective attachment of citrate capped GNPs (on the functionalized polymer by MDEA after 5 hours of immersion in the GNPs colloid (FIG. 1A). While in the absence of the amine, no attachment of the NPs was observed (FIG. 1B).

[0149] Similar attachment of NP were obtained when the PETA monomer was functionalized with diethanol amine (DEA), ethanolamine (EA) or diethyl amine, in the conditions described above.

Example 2: Assembly According to the Invention of NPs on Multiple Dimensions and Continuous Length Scale

[0150] A uniqueness of the process of the invention is the ability to assemble NPs on multiple dimensions and on continuous length scales, notably through direct laser writing by TPL, which allows writing any 1D, 2D and 3D structure by introducing the numerical script of the desired design in the software (Passinger et al. Adv. Mater. 2007, 19, 1218; Klein et al. Adv. Mater. 2010, 22, 868). As seen in FIG. 2, the SEM images show the attachment of GNPs on the 3D (FIGS. 2A and B), planar (FIG. 2C) and linear (FIG. 2D) structures. The GNPs attachment according to example 1 is obtained only on the polymer surface, without any aggregations appearing even on the complex 3D microstructures, and leaving a clean substrate surface. This confirms the high selectivity of the citrate capped GNPs towards the functionalized polymer surface and the efficiency of the method of the invention.

[0151] Besides the ability of multiple dimension fabrications, also by direct laser writing it is possible to control the gap size of the 3D microstructures, and thus the fabrication of different woodpiles of different periods (FIGS. 3A, B, C and D) which have important properties in photonic crystal applications. The interest of the obtained results is that the GNPs penetrate inside the woodpiles porosities and are immobilized also on the inner layers (FIG. 3E) and even on the bottom layers (FIG. 3F).

Example 2: Preparation of a Polystyrene (PS) Functionalized Polymer

[0152] Besides the GNPs immobilization, commercial PS nanoparticles spheres, stabilized by carboxylate ligands, of an average diameter≈800 nm were successfully assembled following a procedure similar to the one of example 1, showing the capability of the process of the invention to assemble NPs that have large diameters.

Example 3: Preparation of Silver NPs Functionalized Polymer

[0153] Citrated silver nanoparticles (AgNPs) of an average diameter of 30-45 nm were successfully attached on the polymer structures and their extinction spectrum shows a plasmonic peak on the planar polymer template at 416 nm.

Example 4: Immobilization of Quantum Dots on Patterned Functionalized Polymer

[0154] Quantum dots (Qds), both commercial and homemade, were successfully attached on functionalized polymer.

[0155] The commercial QDs are PEG-COOH coated CdSe/ZnS red Qds with emission peak at 620±10 nm, were purchased from Mesolight.

[0156] CdSe/CdS/ZnS red Qds and CdSe/ZnS green Qds stabilized by oleic acid and TOP ligands were synthesized with emission peaks at 623 and 523±10 nm respectively following J. Kwak et al. (Nano Lett., vol. 12, no. 5, pp. 2362-2366, 2012).

[0157] For the synthesized Qds, a ligand exchange was performed by mercaptopropanoic acid (MPA) according to Dubois et al. (J. Am. Chem. Soc. 2007, 129, 3, 482-483), in order to attach them on the functionalized polymer.

[0158] The obtained material displays emission at 605 nm or 625 nm.

Example 5: Surface Enhanced Raman Spectroscopy (SERS) Applications

[0159] Raman spectra of trans-1,2-bis-(4-pyridyl)-ethylene molecule (BPE) of 10.sup.−1 M was performed on glass substrate, and the SERS measurement of BPE of 10.sup.−5 M were performed on 2D (flat square microstructures) and 3D (woodpile of period 1.5 μm according to example 2) assemblies of GNPs. The SERS signals show an analytical enhancement factor (AEF) of the ring vibration peak at 1195 cm.sup.−1 on 3D substrate 9.4 times stronger than on 2D substrate.

Example 6: Preparation of a GNP Functionalized Polymer Comprising Polymerized Amine-Functionalized PETRA or DiTMPTA Monomer Units According to the Invention

[0160] Unless mentioned otherwise, the used protocol was similar to the one described in example 1.

Preparation of the Amine-Functionalized Monomer

[0161] Tetrafunctional pentaerythritol tetraacrylate (PETRA) and di(trimethylolpropane tetraacrylate (DiTMPTA) monomers were functionalized by 10% in weight of methyldiethanol amine (MDEA), according to oxa-Michael addition reaction.

Preparation of the Amine-Functionalized Polymer

[0162] 1% of ITX photoinitiator and 10% of inhibitor were added to the amine-functionalized monomers as described above in order to initiate the two photon polymerization process and then yield the two corresponding amine-functionalized polymers

Functionalization with Gold Nanoparticles (GNP)

[0163] The amine-functionalized polymers obtained in the previous step were functionalized with GNP accordingly to the invention.

Results

[0164] The scanning electron microscopy (SEM) images show clearly the selective and high attachment of the GNPs on the above-mentioned functionalized polymers by MDEA.

Example 7: Preparation of a GNP Functionalized Polymer Comprising Polymerized Tertiary Amine-Functionalized Monomer Units According to the Invention

[0165] Unless mentioned otherwise, the used protocol was similar to the one described in example 1.

Preparation of the Amine-Functionalized Monomer

[0166] PETA monomer was functionalized by 10% in weight of a tertiary amine, triethanol amine or N-ethyldiethanol amine, according to oxa-Michael addition reaction.

Preparation of the Amine-Functionalized Polymer

[0167] 1% of ITX photoinitiator and 10% of MEHQ inhibitor were added to the amine-functionalized monomers as described above in order to initiate the two photon polymerization process and then yield the two corresponding amine-functionalized polymers.

Functionalization with Gold Nanoparticles (GNP)

[0168] The amine-functionalized polymers obtained in the previous step were functionalized with GNP accordingly to the invention.

Results

[0169] The scanning electron microscopy (SEM) images show clearly the selective and high attachment of the GNPs on the above-mentioned functionalized polymers by triethanol amine and N-ethyldiethanol amine.

Example 8: Preparation of a GNP Functionalized Polymer Comprising Polymerized Ammonia-Functionalized Monomer Units According to the Invention

[0170] Unless mentioned otherwise, the used protocol was similar to the one described in example 1.

Preparation of the Amine-Functionalized Monomer

[0171] PETA monomer was functionalized by 10% in weight of ammonia, according to oxa-Michael addition reaction.

Preparation of the Amine-Functionalized Polymer

[0172] 1% of ITX photoinitiator and 10% of MEHQ inhibitor were added to the amine-functionalized monomers as described above in order to initiate the two photon polymerization process and then yield the corresponding amine-functionalized polymer.

Functionalization with Sold Nanoparticles (GNP)

[0173] The amine-functionalized polymer obtained in the previous step was functionalized with GNP accordingly to the invention.

Results

[0174] The scanning electron microscopy (SEM) images show clearly the selective and high attachment of the GNPs on the above-mentioned functionalized polymer by ammonia.

Example 9: Accessibility of the NPs Immobilized on the Functionalized Polymers of the Invention

[0175] It has been shown that the gold nanoparticles immobilized on a 2D or 3D polymer layer of the invention can be used for the detection of organic molecules that adsorb to the surface of these nanoparticles.

[0176] The detection was performed by Raman micro-spectrometry using the SERS effect.

[0177] The signal 1 in FIG. 4B corresponds to a solution of the target molecule without the layer of gold nanoparticles. The signals 2 and 3 correspond to the same solution (but 10000 times less concentrated) in the presence of a layer of gold nanoparticles assembled on 2D and 3D polymer structures according to the invention, respectively.

[0178] It is clear from these results that a very significant amplification of the signal was obtained in the presence of the gold nanoparticles immobilized on the polymer surface according to the invention.

[0179] On the contrary, the nanoparticles of a nanocomposite (NPs containing polymer obtained by mixing said NPs with the corresponding monomer prior to polymerization) are not on the surface of said nanocomposite, and thus not accessible. In consequence, no signal from the target molecule will be obtained for these NPs containing polymers.