T-butyl Methacrylate Research Articles

Sequential Infiltration Synthesis of Silicon Dioxide in Polymers with Ester Groups-Insight from In Situ Infrared Spectroscopy.

New strategies to synthesize nanometer-scale silicon dioxide (SiO2) patterns have drawn much attention in applications such as microelectronic and optoelectronic devices, membranes, and sensors, as we are approaching device dimensions shrinking below 10 nm. In this regard, sequential infiltration synthesis (SIS), a two-step gas-phase molecular assembly process that enables localized inorganic material growth in the targeted reactive domains of polymers, is an attractive process. In this work, we performed in situ Fourier transform infrared spectroscopy (FTIR) measurements during SiO2 SIS to investigate the reaction mechanism of trimethylaluminum (TMA) and tri(tert-pentoxy) silanol (TPS) precursors with polymers having ester functional groups (poly(methyl methacrylate) (PMMA), poly(ethyl methacrylate) (PEMA), polycaprolactone (PCL), and poly(t-butyl methacrylate) (PBMA)), for the purpose of growing patterned nanomaterials. The FTIR results show that for PMMA and PEMA, a lower percentage of functional groups participated in the reactions and formed weak and unstable complexes. In contrast, almost all functional groups in PCL and PBMA participated in the reactions and showed stable and irreversible interactions with TMA. We discovered that the amount of SiO2 formed is not directly correlated with the number of interacting functional groups. These insights into the SiO2 SIS mechanism will enable nanopatterning of SiO2 for low-dimensional applications.

High-Sensitivity Mechanochromic Sensor Using Core-Shell Colloidal Crystals

The Colloidal Crystals-based mechanochromic sensor changes color as the arrangement of colloidal particles changes in response to mechanical deformation, which can be detected through optical measurement. This type of sensor can be used in various applications, such as automobile collision detection, structural deformation detection, and medical equipment, among others. In this study, we prepared a stretchable film by dispersing surface-functionalized colloidal particles in an elastic polymer matrix. Surface of silica colloidal particle was modified with an initiator for Atom Transfer Radical Polymerization (ATRP), followed by surface-initiated ATRP of poly(t-butyl methacrylate) (PtBMA). The core-shell colloidal particles were composited with various acrylic monomers, to fabricate crystalline colloidal array which transforms to elastic film by photopolymerization exhibiting structural color. The prepared film showed a clear color change for deformation within 10%, and the peak reflectance showed more than 30%.

Nanoconfined Pores of Poly(4-vinylpyridine) Polystyrene and Poly(tert-butyl methacrylate)Polystyrene Block Copolymers: Electroanalytical Study and Carbon Dioxide Reduction

The performance of electrocatalysis and chemical synthesis within nanodomains is of interest as a novel means of producing chemical products. Self-assembled block copolymers (BCPs) provides us with a means of conducting these reactions. BCPs undergo a phenomenon known as microphase separation where two immiscible polymer subunits undergo reorganization to form highly ordered nanodomains. The incorporation of a small organic molecule within BCPs followed by extraction of these small molecules allows for the production of nanoporous domains that can function as nanovessels for chemical reactions. Polystyrene-Poly(4-vinylpyridine) and Poly(t-butyl methacrylate)-Poly(4-vinylpyridine) is used in this study as the BCPs of interest. Electrochemistry allows us to analyze and perform chemical synthesis within these nanoporous domains. One reaction we are looking at is the electrochemical reduction of carbon dioxide (CO2RR). Due to the nature of these nanovessels, reactions that are energetically unfavorable in the macroscale may prove feasible due to many factors including, reduce degrees of freedom for the reactants, high concentration of protons within these pores, and highly charged electronic environment.

Micellization of poly(2-vinylpyrridine)-b-poly(cyclohexyl methacrylate) (P2VP-b-PCHMA) block copolymers and their interpolymer complex formation in non-aqueous medium

HypothesisThe interpolymer complex formation between poly(vinylpyridine)-based polymers with poly(acrylic acid) (PAA), in aqueous or organic medium, is driven by the hydrogen-bonding complexation. Well-defined nanostructures, with specific practical applications, may be obtained by taking advantage of such non-covalent interactions. ExperimentsPoly(2-vinylpyridine)-b-poly(cyclohexyl methacrylate) (P2VP-b-PCHMA) and poly(2-vinylpyridine)-b-poly(t-butyl methacrylate)-b-poly(cyclohexyl methacrylate) (P2VP-b-PtBuMA-b-PCHMA) copolymers were synthesized by sequential anionic polymerization. Their micellar characteristics were examined as a function of their molecular characteristics in methylcyclohexane and toluene respectively, as cycloaliphatic and aromatic solvents for the selective solubilization of the PCHMA sequence. The size of interpolymer complexes was determined by DLS, in 1,4 dioxane, and their structural composition was characterized by 1H NMR. FindingsThe scaling relationship between the molecular composition and the micellar characteristics, such as particle size and aggregation number, could be established for the PCHMA-based copolymers in methylcyclohexane. It was further demonstrated that controlled micellization in 1,4 dioxane, as a non-selective organic solvent, could be achieved by hydrogen bond type interpolymer complex formation between P2VP-b-PCHMA and PAA-b-PCHMA under stoichiometric P2VP/PAA conditions. Finally, the size of the PCHMA-b-PAA/P2VP block copolymer/homopolymer complexes as well as of the PCHMA-b-PAA/PCHMA-b-P2VP block copolymer/block copolymer complexes was correlated with the molecular characteristics of the copolymers.

Miniemulsion polymerization using graphene oxide as surfactant: In situ grafting of polymers

The occurrence of covalent grafting of polymer chains onto graphene oxide (GO) sheets during aqueous miniemulsion radical polymerizations of common vinyl monomers has been investigated. Styrene, benzyl methacrylate and t-butyl methacrylate were polymerized via miniemulsion polymerization using GO as sole surfactant, and the characterization of GO isolated post-polymerization was investigated by a range of experimental techniques (Fourier-Transform Near Infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), Differential Scanning Calorimetry (DSC), X-Ray Photoelectron spectroscopy (XPS), Raman spectroscopy and X-Ray Diffraction (XRD)). All experimental techniques show consistently that significant grafting occurs for all three monomers under these conditions. Furthermore, Raman spectroscopy indicated that the mechanism of grafting involves the sp2 carbons present in the GO structure, and not the oxygen-containing functional groups (e.g. epoxy, hydroxyl and carboxyl). The extent of grafting was quantified by XPS, revealing that polymer grafting occurred at levels in the approximate range of 20–60 wt% (grafted polymer relative to total mass of GO and grafted polymer). Miniemulsion polymerization using GO as surfactant is an attractive approach for synthesis of polymer/GO nanocomposites, and the present results are important in regards to the specific structures and performances of such materials.

Modified Poly(T-Butyl Methacrylate) as a Doxorubicin Carrier for Targeted Delivery

Poly(t-butyl methacrylate) (PTBMA) was selected as a doxorubicin carrier for targeted delivery because it can hydrolyze to form water-soluble polymers. A chain-transfer reaction with thioglycolic acid was used. The thioglycolic acid concentration was 1 mass%, at which a polymer with the optimal biocompatibility (molecular mass ~12 kDa, polydispersion index Mw/Mn ≈ 1.5) was obtained. The polymer was chemically modified by a folate vector. The resulting polymer was converted via acid hydrolysis into a water-soluble copolymer. Then, a conjugate of doxorubicin (DOX) with the copolymer of t-butyl methacrylate and methacrylic acid modified by the folate vector on the terminal carboxylates was prepared. The degree of DOX conjugation to the polymer was 62.7 ± 11.8%. DOX was released from the polymer system almost three times faster at pH 4.6 than at pH 7.4. The cytotoxicity of the polymer conjugate was 1.52 μM.

Efficient synthesis of cRGD functionalized polymers as building blocks of targeted drug delivery systems

Synthetic peptides with cyclic arginine-glycine-aspartate motif (cRGD) play an important role in cell recognition and cell adhesion. cRGD-decorated soluble polymers and polymeric nanoparticles have been increasingly used for cell-specific delivery of antitumor drugs. While the significance of cRGD modification for tumor cell-specific targeting of polymeric carriers is well-accepted, straightforward procedures ensuring the fidelity of cRGD modification of polymeric systems are still lacking. Herein, we have reported an in-situ polymerization approach for synthesis of cRGD-end-functionalized well-defined polymers as potential building blocks of targeted drug delivery systems. A new cRGD peptide functionalized RAFT agent was synthesized as confirmed by MALDI-TOF and 1H NMR spectroscopy. The ability of this RAFT agent to control polymerizations was then tested using two different monomers oligoethyleneglycol acrylate and t-butyl methacrylate. The RAFT-controlled character of polymerizations and the living characteristic of the synthesized polymers were investigated through a series of kinetic experiments. The cytotoxicity and targeting capability of cRGD-functionalized OEGA polymers were investigated using cell lines expressing αvβ3 integrins at varying extents.

Low-Power All-Organic Electrophoretic Display Using Self-Assembled Charged Poly( t-butyl methacrylate) Microspheres in Isoparaffinic Fluid.

The increasing demands for display devices with low power consumption and outdoor readability have stimulated comprehensive research into full-color reflective displays that employ color-tunable photonic crystal technologies. Although the recently developed crystalline colloidal arrays (CCAs) of the charged microspheres have shown the outstanding color tunability, the practical application is limited because the use of highly polar liquid medium such as water is required to maintain the charges on the surface of microsphere, whereas it is not suitable for long-term use in an electric field. Herein, a self-assembled CCA from charged poly( t-butyl methacrylate) microspheres was successfully fabricated, which was stabilized by the charged inverse micelles of sodium di-2-ethylhexyl-sulfosuccinate in a nonpolar isoparaffinic fluid. A charged all-organic CCA was found to exhibit full-color tunability with a 1000-fold reduction in the power consumption (∼6 μW cm-2) under a direct current voltage bias of 4 V in comparison to that in an aqueous system, which is a promising feature for a low-power-consumption display device.

The lower alkyl methacrylates: Genotoxic profile of non-carcinogenic compounds

All of the lower alkyl methacrylates are high production chemicals with potential for human exposure. The genotoxicity of seven mono-functional alkyl esters of methacrylic acid, i.e. methyl methacrylate, ethyl methacrylate, hydroxyethyl methacrylate, n-, i- and t-butyl methacrylate and 2 ethyl hexyl methacrylate, as well as methacrylic acid itself, the acyl component common to all, is reviewed and compared with the lack of carcinogenicity of methyl methacrylate, the representative member of the series so evaluated. Also reviewed are the similarity of structure, chemical and biological reactivity, metabolism and common metabolic products of this group of compounds which allows a category approach for assessing genotoxicity. As a class, the lower alkyl methacrylates are universally negative for gene mutations in prokaryotes but do exhibit high dose clastogenicity in mammalian cells in vitro. There is no convincing evidence that these compounds induce genotoxic effects in vivo in either sub-mammalian or mammalian species. This dichotomy of effects can be explained by the potential genotoxic intermediates generated in vitro. This genotoxic profile of the lower alkyl methacrylates is consistent with the lack of carcinogenicity of methyl methacrylate.

Polymer brushes modified by photosensitive azobenzene containing polyamines

Abstract This paper describes a strategy for preparing photosensitive polymeric grafts on flat solid surfaces by loading diblock-copolymer or homopolymer brushes with cationic azobenzene-containing surfactants. In contrast to previous work, we utilize photosensitive surfactants that bear positively-charged polyamine head groups whose charge varies between 1+ and 3+. Poly(methylmethacrylate-b-methacrylic acid) (PMMA-b-PMAA) brushes were prepared by employing atom transfer radical polymerization, where the bottom poly(methyl methacrylate) block was grown first followed by the synthesis of t-butyl methacrylate block that after de-protection yielded poly(methacrylic acid). We used PMMA-b-PMAA brushes with constant grafting density and length of the PMMA block, and three different lengths of the PMAA block. The azobenzene-based surfactants attached only to the PMAA block. The degree of binding (i.e., the number of surfactant molecules per binding site on the brush backbone) of the surfactants to the brush depends strongly on the valence of the surfactant head-group; within the brushes the concentration of the surfactant carrying unit charge is larger than that of multivalent surfactants. We detect pronounced response of the brush topography on irradiation with UV interference pattern even at very low degree of binding (as small as 0.08) of multi-valence surfactant. Areas on the sample that receive the highest UV dose exhibit chain scission. By removing the ruptured chains from the substrate via good solvent, one uncovers a surface topographical relief grating, whose spatial arrangement follows the intensity distribution of the UV light on the sample during irradiation. Due to strong coupling of the multi-valence surfactants to the polymer brush, it was possible in some cases to completely remove the polyelectrolyte block from the PMMA layer. The application of multi-valence azobenzene surfactants for triggering brush photosensitive has important advantage over usage of surfactant with unit charge because relative to single-valence surfactants much lower concentrations of the multivalent surfactant are needed to achieve comparable response upon UV irradiation.

Fractionation of Poly(butyl methacrylate) by Molecular Topology Using Multidetector Thermal Field-Flow Fractionation.

Thermal field-flow fractionation (ThFFF) is an interesting alternative to column-based fractionation being able to address different molecular parameters including size and composition. Until today it has not been shown to be able to fractionate polymers of similar molar masses and chemical compositions by molecular topology. The present study demonstrates that poly(butyl methacrylates) with identical molar masses can be fractionated by ThFFF according to the topology of the butyl group. The influence of the solvent polarity on the thermal diffusion behavior of these polymers is presented and it is shown to have a significant influence on the fractionation of poly(n-butyl methacrylate) and poly(t-butyl methacrylate). Fractionation improves with increasing solvent polarity and solvent polarity may have a greater influence on fractionation than solvent viscosity. It is found that the thermal diffusion coefficient, D(T), as well as the hydrodynamic diameter, D(h), exhibit increasing trends with increasing solvent polarity. The solvent quality has a significant influence on the fractionation. It is found that cyclohexane, being a theta solvent for poly(t-butyl methacrylate) but not for poly(n-butyl methacrylate), significantly improves the fractionation of the samples by decreasing the diffusion rate of the former but not the latter.

PH-triggered PMAA-b-HTPB-b-PMAA copolymer micelles: physicochemical characterization and camptothecin release

pH-sensitive poly(methacrylic acid)-block-hydroxyl-terminated polybutadiene-block-poly(methacrylic acid) block copolymers were synthesized by atom transfer radical polymerization of t-butyl methacrylate and follow-up acidolysis. The copolymers can spontaneously assemble into stable and nearly spherical micelle aggregates in aqueous solution, with hydrodynamic diameters (D h ) from 51 to 92 nm and critical micelle concentration of 3.90–7.76 mg L−1. Zeta potentials were found to be increased with increasing (monomer)/(initiator) molar ratios. A pH-dependent phase behavior is produced at approximately 5.4–5.6, as determined by D h and I 335/I 332 fluorescence intensity ratios. The in vitro camptothecin (CPT) release was compositional and pH dependent, and the cumulative CPT release below pH 7.2 was higher than that in pH 7.4. They could inhibit the premature burst CPT release. The copolymer micelles were low in cytotoxicity even at a micellar concentration of 800 mg L−1, and therefore they may be used as potential drug-delivery carriers.

Opto-Mechanical Scission of Polymer Chains in Photosensitive Diblock-Copolymer Brushes

In this paper we report on an opto-mechanical scission of polymer chains within photosensitive diblock-copolymer brushes grafted to flat solid substrates. We employ surface-initiated polymerization of methylmethacrylate (MMA) and t-butyl methacrylate (tBMA) to grow diblock-copolymer brushes of poly(methylmethacrylate-b-t-butyl methacrylate) following the atom transfer polymerization (ATRP) scheme. After the synthesis, deprotection of the PtBMA block yields poly(methacrylic acid) (PMAA). To render PMMA-b-PMAA copolymers photosensitive, cationic azobenzene containing surfactants are attached to the negatively charged outer PMAA block. During irradiation with an ultraviolet (UV) interference pattern, the extent of photoisomerization of the azobenzene groups varies spatially and results in a topography change of the brush, i.e., formation of surface relief gratings (SRG). The SRG formation is accompanied by local rupturing of the polymer chains in areas from which the polymer material recedes. This opto-mechanically induced scission of the polymer chains takes place at the interfaces of the two blocks and depends strongly on the UV irradiation intensity. Our results indicate that this process may be explained by employing classical continuum fracture mechanics, which might be important for tailoring the phenomenon for applying it to poststructuring of polymer brushes.

Assembly of foam and honeycomb films of a diblock copolymer doped with Au or Ag nanoparticles at the liquid/liquid interface and their catalytic properties

Composite thin films of poly(t-butyl methacrylate)-block-poly(2-vinyl pyridine) (PtBMA-b-P2VP) doped with silver or gold nanoclusters or nanoparticles were fabricated at the liquid/liquid interface between the polymer chloroform solution and AgNO3 or HAuCl4 aqueous solution. The formation of the thin films results from the adsorption of the polymer molecules at the interface, combination with the inorganic species in the water phases, and self-assembly of the composite molecules. Different from homo-P2VP and polystyrene-block-poly(2-vinyl pyridine) (PS-b-P2VP) that self-assemble into foam film and honeycomb structure, respectively, two kinds of morphologies (foam and honeycomb structures) are formed simultaneously for PtBMA-b-P2VP, reflecting different assembling behaviors of these polymers at the interface. Silver or gold nanoclusters or nanoparticles were generated in the polymer films during the assembly process and further reduction of the combined precursors, which show high catalytic activity and durability for the reduction of 4-nitrophenol and other nitro-compounds.

Tunable, responsive nanogels containing t-butyl methacrylate and 2-(t-butylamino)ethyl methacrylate

We present the synthesis and characterization of a series of pH-responsive hydrogel nanoparticles based on crosslinked 2-(diethylaminoethyl) methacrylate and poly(ethylene glycol) methyl ether methacrylate (P(DEAEMA-g-PEGMA)). Variants of this polymer were created using t-butyl methacrylate (P(DEAEMA-co-TBMA-g-PEGMA)) or t-butylaminoethyl methacrylate (P(DEAEMA-co-TBAEMA-g-PEGMA)). The synthesis of these materials was accomplished using a facile photoemulsion polymerization. Polymer composition was verified using 1H NMR spectroscopy and closely approximates the copolymer composition estimated from reactivity ratios. Particle formulations possess a dry diameter of 50–65 nm as determined by transmission electron microscopy and collapsed hydrodynamic diameter of 70–100 nm as determined by dynamic light scattering. Dynamic light scattering and pyrene fluorescence spectroscopy were used to probe the pH-dependent phase transition in the hydrogel nanoparticles from collapsed hydrophobe to swollen hydrophile. The inclusion of t-butyl methacrylate served to depress the nanogel pKa and critical pH for phase transition to <6.9 while the inclusion of t-butylamino methacrylate had the opposite effect. We show that these hydrogel nanoparticles possess tunable physicochemical properties that can be adjusted by changing copolymer composition.

PH-labile sheddable block copolymers by RAFT polymerization: Synthesis and potential use as siRNA conjugates

Well-defined amphiphilic block copolymers composed of hydrophilic and hydrophobic blocks linked through an acid-labile acetal bond were synthesized directly by RAFT polymerization using a new poly(ethylene glycol) (PEG) macroRAFT agent modified with an acid-labile group at its R-terminal. The new macroRAFT agent was used for polymerization of poly(t-butyl methacrylate) (PtBMA) or poly(cholesterol-methacrylate) (PCMA) to synthesize well-defined block copolymers with a PEG block sheddable under acidic conditions. The chain extension polymerization kinetics showed known traits of RAFT polymerization. The molecular weight distributions of the copolymers prepared using the new macroRAFT agent remained below 1.2 during the polymerizations and the molecular weight of the copolymers was linearly proportional to monomer conversions. The acid-catalyzed hydrolysis behavior of the PEG-macroRAFT agent and the PEG-b-PtBMA (Mn=13,600 by GPC, PDI=1.10) was studied by GPC, 1H NMR and UV–vis spectroscopy. The half-life of acid-hydrolysis was 70min at pH 2.2 and 92h at pH 4.0. The potential use of the pH-labile shedding behavior of the copolymers was demonstrated by conjugating a thiol-modified siRNA to ω-pyridyldisulfide modified PEG-b-PCMA. The resultant PEG-b-PCMA-b-siRNA triblock modular polymer released PCMA-b-siRNA segment in acidic and siRNA segment in reductive conditions, as confirmed by polyacrylamide gel electrophoresis.

PH-responsive destabilization and facile bioconjugation of new hydroxyl-terminated block copolymer micelles

New hydroxyl-terminated amphiphilic block copolymers (HO-ABPs) having pendant t-butyl groups for pH-responsiveness and terminal OH groups for bioconjugation are reported. These HO-ABPs consist of hydrophilic poly(oligo(ethylene oxide) monomethyl ether methacrylate) and hydrophobic poly(t-butyl methacrylate) blocks and were synthesized by a consecutive atom transfer radical polymerization in the presence of an OH-terminated bromine initiator. Aqueous self-assembly of HO-ABPs resulted in colloidally stable micellar aggregates being capable of encapsulating hydrophobic guest molecules. They were nontoxic to cells and destabilized in response to low pH. A facile bioconjugation of HO-ABP micelles for active targeting is demonstrated by conjugation with biotin (vitamin H) and competitive assay exhibiting >93% ABP chains conjugated with biotin in each micelle. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

Synthesis, thermo-responsive micellization and caffeine drug release of novel PBMA-b-PNIPAAm block polymer brushes

Brush-like block copolymers with poly(t-butyl methacrylate) (PBMA) and poly(N-isopropylacrylamide) (PNIPAAm) as side arms, PBMA-b-PNIPAAm, were designed and synthesized via a simple free radical polymerization route. The chemical structure and molecular weight of these polymer brushes were characterized and determined by nuclear magnetic resonance (1H NMR), Fourier transform infrared spectrometry (FTIR) and gel permeation chromatography (GPC). The micellar formation by these polymer brushes in aqueous solutions were detected by a surface tension technique, and the critical micelle concentration (CMC) ranged from 1.53 to 8.06 mg L−1. The morphology and geometry of polymer micelles were investigated by transmission electron microscope (TEM) and dynamic light scattering (DLS). The polymer micelles assume the regularly-spherical core-shell structure with well-dispersed individual nanoparticles, and the particle size was in the range from 36 to 93 nm. The PNIPAAm segments exhibited a thermoreversible phase transition, so the resulting block polymer brushes were temperature-sensitive and the low critical solution temperature (LCST) was determined by UV-vis spectrometer at about 28.82–29.40°C. The characteristic parameters of the polymer micelles such as CMC, micellar size and LCST values were affected by their compositional ratios and the length of hydrophilic or hydrophobic chains. The evaluation for caffeine drug release behavior of the block polymer micelles demonstrated that the self-assembled micelles exhibited thermal-triggered properties in controlled drug release.

Thermal-Sensitive PBMA-b-PNIPAAm Amphiphilic Block Copolymers Brushes and Their Assembling Micelles

Brush-like block copolymers with poly(t-butyl methacrylate) (PBMA) and poly(N-ispropylacrylamide) (PNIPAAm) as side arms, PBMA-b-PNIPAAm, were designed and synthesized via a simple free radical polymerization route. The chemical structure of these polymer brushes was characterized and determined by nuclear magnetic resonance (1H NMR), and Fourier transform infrared spectrometry (FT-IR). The micellar formation by these polymer brushes in aqueous solutions were detected by a surface tension technique, and the critical micelle concentration (CMC) ranged from 1.53 to 8.06 mg L(-1). The morphology and geometry of polymer micelles were investigated by transmission electron microscope (TEM) and dynamic light scattering (DLS). The polymer micelles assume the regularly-spherical core-shell structure with well-dispersed individual nanoparticles, and the particle size was in the range from 36 to 93 nm. The PNIPAAm segments exhibited a thermoreversible phase transition, so the resulting block polymer brushes were temperature-sensitive and the low critical solution temperature (LCST) was determined by UV-vis spectrometer at about 28.82-29.40 degrees C. The characteristic parameters of the polymer micelles such as CMC, micellar size and LCST values were affected by their compositional ratios and the length of hydrophilic or hydrophobic chains. The self-assembled micelles are expected to be used in specific biomedical fields as a candidate of drug controlled release carrier.

Synthesis, micellization and caffeine drug release kinetics of novel PBMA-b-PNIPAAm block polymer brushes

Brush-like block copolymers with poly(t-butyl methacrylate) (PBMA) and poly(N-ispropylacrylamide) (PNIPAAm) as side arms, PBMA-b-PNIPAAm, were designed and synthesized via a simple free radical polymerization route. The chemical structure and molecular weight of these polymer brushes were characterized and determined by nuclear magnetic resonance (1H NMR), Fourier transform infrared spectrometry (FT-IR) and gel permeation chromatography (GPC). The polymer brushes can spontaneously assembled into regularly spherical core–shell nanostructured micelles with well-dispersed individual nanoparticles in aqueous solutions, and physiochemical properties of the micelles formed were detected by a surface tension technique, nanoparticle analyzer, transmission electron microscope (TEM), dynamic light scattering (DLS) and UV–vis transmittance measurements. Low critical micelle concentration (CMC) and high zeta potentials revealed the micellar stability and the micellar particle size was in the range from 36 to 93nm by TEM and less than 200nm by DLS. The resulting block polymer brushes were temperature-sensitive with low critical solution temperature (LCST) about 28.80–29.40°C. These characteristic parameters were affected by their compositional ratios and the length of hydrophilic or hydrophobic chains. The evaluation for caffeine drug release and release kinetics demonstrated that the drug release and bioavailability may be mediated or improved by the temperature-induced structural changes of the micelles and different diffusion mechanism.