Two-step Atom Transfer Radical Polymerization Research Articles

Nanoporous Block Copolymer Membranes with Enhanced Solvent Resistance Via UV-Mediated Cross-Linking Strategies.

In this work, a block copolymer (BCP) consisting of poly((butyl methacrylate-co-benzophenone methacrylate-co-methyl methacrylate)-block-(2-hydroxyethyl methacrylate)) (P(BMA-co-BPMA-co-MMA)-b-P(HEMA)) is prepared by a two-step atom-transfer radical polymerization (ATRP) procedure. BCP membranes are fabricated applying the self-assembly and nonsolvent induced phase separation (SNIPS) process from a ternary solvent mixture of tetrahydrofuran (THF), 1,4-dioxane, and dimethylformamide (DMF). The presence of a porous top layer of the integral asymmetric membrane featuring pores of about 30nm is confirmed via scanning electron microscopy (SEM). UV-mediated cross-linking protocols for the nanoporous membrane are adjusted to maintain the open and isoporous top layer. The swelling capability of the noncross-linked and cross-linked BCP membranes is investigated in water, water/ethanol mixture (1:1), and pure ethanol using atomic force microscopy, proving a stabilizing effect of the UV cross-linking on the porous structures. Finally, the influence of the herein described cross-linking protocols on water-flux measurements for the obtained membranes is explored. As a result, an increased swelling resistance for all tested solvents is found, leading to an increased water flux compared to the pristine membrane. The herein established UV-mediated cross-linking protocol is expected to pave the way to a new generation of porous and stabilized membranes within the fields of separation technologies.

Understanding the Synthesis of Linear–Bottlebrush–Linear Block Copolymers: Toward Plastomers with Well-Defined Mechanical Properties

Linear–bottlebrush–linear (LBL) triblock copolymers were synthesized via a two-step atom transfer radical polymerization (ATRP): (i) grafting-through polymerization of monomethacryloxypropyl-termin...

Self-Assembly of Linear Amphiphilic Pentablock Terpolymer PAAx-PS48-PEO46-PS48-PAAxin Dilute Aqueous Solution.

A series of linear amphiphilic pentablock terpolymer PAAx-b-PS48-b-PEO46-b-PS48-b-PAAx (AxS48O46S48Ax) with various lengths x of the PAA block (x = 15, 40, 60, and 90) were synthesized via a two-step atom transfer radical polymerization (ATRP) using Br-poly(ethylene oxide)-Br (Br-PEO46-Br) as the macroinitiator, styrene (St) as the first monomer, and tert-butyl acrylate (tBA) as the second monomer, followed with the hydrolysis of PtBA blocks. The AxS48O46S48Ax pentablock terpolymers formed micelles in dilute aqueous solution, of which the morphologies were dependent on the length x of the PAA block. Cryogenic transmission electron microscopy (cryo-TEM), dynamic light scattering (DLS), and zeta potential measurement were employed to investigate the morphologies, chain structures, size, and size distribution of the obtained micelles. The morphology of AxS48O46S48Ax micelles changed from spherical vesicles with ordered porous membranes to long double nanotubes, then to long nanotubes with inner modulated nanotubes or short nanotubes, and finally, to spherical micelles or large compound vesicles with spherical micelles inside when x increased from 15 to 90. The hydrophobic PS blocks formed the walls of vesicles and nanotubes as well as the core of spherical micelles. The hydrophilic PEO and PAA block chains were located on the surfaces of vesicle membranes, nanotubes, and spherical micelles. The PAA block chains were partially ionized, leading to the negative zeta potential of AxS48O46S48Ax micelles in dilute aqueous solutions.

Self-Assembly of Thermosensitive Amphiphilic Pentablock Terpolymer PNIPAMx-b-PtBA90-b-PPO36-b-PtBA90-b-PNIPAMx in Dilute Aqueous Solution

A series of linear thermosensitive amphiphilic pentablock terpolymers PNIPAMx-b-PtBA90-b-PPO36-b-PtBA90-b-PNIPAMx (NxT90O36T90Nx) with various lengths x of PNIPAM block (x = 111, 107, 95, 58, 33, a...

Boronate affinity monolith via two-step atom transfer radical polymerization for specific capture of cis-diol-containing compounds

Boronate affinity (BA) monolith is an important tool for uniquely selective capture of cis-diol-containing compounds. However, most of BA monoliths suffer from limited binding sites. In this work, a high-capacity BA monolith was successfully synthesized via simple two-step atom-transfer radical polymerization method. Fourier transform infrared spectra, scanning electron microscope and Brunauer–Emmett–Teller surface area analyzer were used to characterize the resultant BA monolith. The BA monolith could selective capture of cis-diol-containing small molecular compounds and protein macromolecules with all aqueous mobile phase at pH of 8.5. Frontal analysis was applied to measure the adsorption data, and Scatchard equation was used to calculate the C (Qmax) and dissociation constants (Kd). By using polymer chains to amplify the number of binding sites, the binding capacity of BA monolith had been effectively improved to 303.5 and 118.2 μmol g−1 for catechol and adenosine, respectively. Such binding capacity was the highest among already reported BA monoliths. Interestingly, the binding capacity was mainly depended on the molecular volume (or molecular weight) of cis-diol containing compounds with a significant negative correlation. Besides, via synergistic effect of double binding, the BA chains had enhanced the binding strength of BA monolith toward molecules with two cis-diol groups with Kd value of 10−5 M, which were lower than that of molecules with one cis-diol group by one order of magnitude. The results indicated that the binding capacity and strength depend on not only the property of BA materials but also the nature of cis-diol-containing compounds.

Superhydrophobic porous surface fabricated via phase separation between polyhedral oligomeric silsesquioxane-based block copolymer and polyethylene glycol

A superhydrophobic porous film was fabricated by a simple phase separation process between a polyhedral oligomeric silsesquioxane (POSS) based diblock polymer (P) and polyethylene glycol (PEG) in selective solvents. The POSS-based hybrid diblock polymer was synthesized using a two-step atom transfer radical polymerization method. The polymer, along with PEG, was dissolved in mixed solvents of tetrahydrofuran (THF) and ethanol (AC), and then dip-coated onto the glass slides to form a coating film. After PEG was washed away using water, the polymer film with nano-micrometer dual-scale roughness on the slides was formed due to the phase separation. Then, a superhydrophobic porous film was obtained after surface modification with low surface energy material. The effects of POSS content, P/PEG ratio, and AC/THF ratio were investigated. The results showed that the water contact angle increased with the PEG content within a certain range and the surface roughness was enhanced after adding AC. When the POSS content was 25.3% (P2), the ratio of P2/PEG was 5:5 and AC/THF was 3:7, the film after modification had a static water contact angle of 155.1° and a sliding angle of 6.5°, demonstrating superhydrophobicity.

Synthesis and assembly of polyhedral oligomeric silsesquioxane end-capped amphiphilic polymer to enhance the fluorescent intensity of tetraphenylethene

In this study, polyhedral oligomeric silsesquioxane (POSS) end-capped amphiphilic POSS-block-poly (N, N-dimethylaminoethyl methacrylate)-block-poly (methyl methacrylate) (POSS-b-PDMAEMA-b-PMMA) was synthesized by a two-step atom transfer radical polymerization (ATRP), and its assembly morphologies in different solvents were investigated. POSS-b-PDMAEMA-b-PMMA micelles were used to encapsulate tetraphenylethene (TPE) to study the effect of self-assembly shape on the fluorescent intensity and bioimaging of TPE. Spherical polymeric micelles enhanced the fluorescent intensity of TPE more than rod-like and necklace-like polymeric micelles while rod-like polymeric micelles had better intracellular uptake than spherical polymeric micelles.

Synthesis and thermal decomposition kinetics of poly(methyl methacrylate)-b-poly(styrene) block copolymers

Two diblock copolymers of poly(methyl methacrylate)- block-poly(styrene) with chlorine as terminal group (PMMA- b-PS-Cl) were synthesized via two-step atom transfer radical polymerization. The structures of the block copolymers were characterized by Fourier transform infrared spectroscopy, proton nuclear magnetic resonance, and gel permeation chromatography. Thermal properties including glass transition temperature ( Tg) and thermal stability were studied by differential scanning calorimetry and thermogravimetric analysis (TGA), respectively. The block copolymers of PMMA- b-PS-Cl exhibited two glass transitions, which were attributed to the Tgs of PMMA and PS segments, respectively. According to TGA, thermal decompositions of PMMA macro-initiator and PMMA- b-PS-Cl block copolymers had two stages. The weight loss ratio in the second stage was more significant than that in the first stage, which may be attributed to the separation of the halogen atom from the terminal group and the formation of a double bond. The breaking down of the backbone dominates in the second stage in which the weight loss ratio was more than 70%, represented the main stage of pyrolysis. It was found that the introduction of the PS chain remarkably enhanced the thermal stability of the copolymer, thus endowing the block copolymers high activation energy for thermal decomposition. On the other hand, the remaining two pyrolysis procedures further indicated that thermodynamic mechanism didn’t change due to the introduction of PS segments.

Conductive Nanowires Templated by Molecular Brushes.

In this paper, we report the fabrication of conductive nanowires using polymer bottle brushes as templates. In our approach, we synthesized poly(2-dimethylamino)ethyl methacrylate methyl iodide quaternary salt brushes by two-step atom transfer radical polymerization, loaded them with palladium salt, and reduced them in order to form metallic nanowires with average lengths and widths of 300 and 20 nm, respectively. The obtained nanowires were deposited between conductive gold pads and were connected to them by sputtering of additional pads to form an electric circuit. We connected the nanowires in an electric circuit and demonstrated that the conductivity of these nanowires is around 100 S·m(-1).

Preparation of a novel polymer monolith with functional polymer brushes by two-step atom-transfer radical polymerization for trypsin immobilization.

Novel porous polymer monoliths grafted with poly{oligo[(ethylene glycol) methacrylate]-co-glycidyl methacrylate} brushes were fabricated via two-step atom-transfer radical polymerization and used as a trypsin-based reactor in a continuous flow system. This is the first time that atom-transfer radical polymerization technique was utilized to design and construct polymer monolith bioreactor. The prepared monoliths possessed excellent permeability, providing fast mass transfer for enzymatic reaction. More importantly, surface properties, which were modulated via surface-initiated atom-transfer radical polymerization, were found to have a great effect on bioreactor activities based on Michaelis-Menten studies. Furthermore, three model proteins were digested by the monolith bioreactor to a larger degree within dramatically reduced time (50 s), about 900 times faster than that by free trypsin (12 h). The proposed method provided a platform to prepare porous monoliths with desired surface properties for immobilizing various enzymes.

Tumor-targeted aggregation of pH-sensitive nanocarriers for enhanced retention and rapid intracellular drug release

Development of nanocarriers, which can selectively accumulate and remain within the tumor tissue matrix, is beneficial for non-invasive cancer diagnosis and therapy. In this study, a well-defined pH-sensitive block copolymer, i.e., succinic anhydride (SA)-modified poly(2-diisopropylaminoethyl methacrylate)-block-poly(2-aminoethyl methacrylate hydrochloride) (PDPA-b-PAMA/SA), was prepared by a two-step atom transfer radical polymerization (ATRP) and subsequent amidation. The low critical micelle concentration (CMC, 40.7 × 10−4 mg mL−1) of PDPA-b-PAMA/SA investigated in pH 7.4 aqueous solution confirmed the adequate thermodynamic stability of its self-assembly. In addition, the pH-sensitive aggregation behaviors of blank and drug-loaded PDPA-b-PAMA/SA were systematically studied at typical pH conditions (7.4 and 6.5) using dynamic light scattering (DLS) and transmission electron microscopy (TEM). Compared with the control sample, i.e., poly(D,L-lactide)-block-poly(2-aminoethyl methacrylate hydrochloride (PLA-b-PAMA/SA), both blank and drug-loaded PDPA-b-PAMA/SA (PDPA-b-PAMA/SA@DOX·HCl) exhibited obvious aggregation through electric interaction between the positive charge of the protonated PDPA block and the negative charge of the PAMA/SA block at tumor sites under slightly acidic condition. Moreover, the drug-loaded nanocarriers exhibited accelerated drug release profiles in response to the acidic condition due to the electric repulsion between the protonated PDPA block and positive DOX·HCl. Cytotoxicity assay results demonstrated that the pH-sensitive block copolymer did not demonstrate obvious cytotoxicity, even at a concentration up to 100 μg mL−1. The enhanced intracellular DOX·HCl distribution in nuclei was also confirmed by confocal laser scanning microscopy (CLSM). Thus, these results suggest that PDPA-b-PAMA/SA provides a feasible platform for efficient tumor-targeted therapy.

Synthesis and Characterization of PEGylated Brush-type Polycation Modified with Galactosamine

Gene therapy has been generally regarded as a promising treatment for numerous hard curable diseases, such as cancer, genetic and infectious diseases. Seeking a safe and efficient vector plays the most challenging role in gene therapy. In the past decades, non-viral polycation has attracted much more attentions as a promising gene vector due to their good biocompatibility, high condensation ability, as well as easily-adjustable and controlled structures. In the present work, a series of galactosamine (Gal)-conjugated brush-type cationic copolymer P(PEGMEMA-co-PEGMA-Gal)-b-PDMAEMA were prepared via a combination of two-step atom transfer radical polymerization (ATRP) technique and polymer reaction. Firstly, random copolymerization of poly(ethylene glycol)methyl ether methacrylate (PEGMEMA) and poly(ethylene glycol) methacrylate (PEGMA) was carried out to yield the copolymer P(PEGMEMA-co-PEGMA), which was further used as a macroinitiator to polymerize 2-(N ,N-dimethylamino)ethyl methacrylate (DMAEMA), producing the cationic copolymer P(PEGMEMA-co-PEGMA)-b-PDMAEMA. Finally, the brush-type copolymer P(PEGMEMA-co-PEGMA-Gal)-bPDMAEMA was obtained by the modification of pendent hydroxyl groups with galactosamine using N,N'-carbonyldiimidazole (CDI) as the coupling agent. PDMAEMA is a well-known pH-sensitive polycation and has been widely applied for non-viral gene delivery, while the brush-type hydrophilic chains provide the carrier with favorable biocompatibility, prolonged blood circulation time, and reduced non-specific adsorption of proteins. PDMAEMA block would be partially protonated to afford some hydrophobic domains and positive charges at neutral condition, which can bind with DNA via electrostatic interaction to form polycation/DNA polyplex. The Gal moiety on the surface made the polyplex easily recognized by asialoglycoprotein receptors (ASGPRs) over-expressing hepatoma cells and internalized via a receptor-mediated endocytosis process. The chemical structures, molecular weights and molecular weight distributions of P(PEGMEMA-co-PEGMA-Gal)-b-PDMAEMA copolymer were characterized by H NMR, FT-IR, and GPC measurements. The DNA binding capacity of this copolymer was investigated by agarose gel electrophoresis and zeta potential measurements, which indicated that DNA migration could be completely retarded when the N/P ratio was higher than 1.5. The DLS DOI: 10.6023/A14030185

Thermoresponsive Oligo(ethylene glycol)-Based Polymer Brushes on Polymer Monoliths for All-Aqueous Chromatography

Porous polymer monoliths onto which were grafted a thermoresponsive copolymer, poly(2-(2-methoxyethoxy)ethyl methacrylate (MEO2MA)-co-oligo(ethylene glycol) methacrylate (OEGMA)), were synthesized by the two-step atom transfer radical polymerization (ATRP) method. The copolymer-grafted monoliths were characterized by elemental analysis, scanning electron microscopy, and mercury intrusion porosimetry. They were further used as the thermoresponsive stationary phase for all-aqueous high-performance liquid chromatography (HPLC). The chromatograms of three steroids demonstrated that the chain length of the grafted copolymer, which was regulated by varying the grafting time, could affect the separation by providing different amounts of hydrophobic interaction sites with analytes. Additionally, the elution profiles of steroids on the stationary phase could also be tuned by the comonomer composition. The results showed that the porous polymer monoliths enabled separation of the test mixture in pure aqueous mobile phase under isocratic conditions. Furthermore, the proposed method provides a simple and promising tool in the design and construction of responsive surfaces for chromatography applications.

Amphiphilic block copolymer modified magnetic nanoparticles for microwave-assisted extraction of polycyclic aromatic hydrocarbons in environmental water

In this work, amphiphilic block copolymer poly(tert-butyl methacrylate)-block-poly(glycidyl methacrylate) (PtBMA-b-PGMA) modified Fe3O4 magnetic nanoparticles (Fe3O4 MNPs) were synthesized, and served as an adsorbent for microwave-assisted extraction of polycyclic aromatic hydrocarbons (PAHs). The PtBMA-b-PGMA block copolymers with different block ratios were prepared by two-step atom transfer radical polymerization (ATRP) and the extraction abilities of their corresponding Fe3O4@PtBMA-b-PGMA were investigated. The key factors affecting the extraction efficiency of the adsorbent, including microwave conditions, amount of adsorbent, type and volume of desorption solvent, were studied in detail. In comparison with vortex, which is a conventional method used for assisting extraction, the proposed microwave-assisted method allowed better extraction efficiency and required a shorter extraction time. The calibration curves of PAHs were obtained in the range of 0.05–120μg/L (r>0.9985) and the limits of detection (S/N=3) were in the range of 2.4–6.3ng/L. The recoveries of PAHs spiked in environmental water samples were between 62.5% and 104% with relative standard deviations (RSDs) ranging from 0.84% to 9.02%. The proposed technique combining microwave-assisted extraction and magnetic separation was demonstrated to be a fast, convenient and sensitive pretreating method for PAHs.

Synthesis, characterization, and micellization of pH-responsive poly(4-vinylpyridine)-block-poly(methacrylic acid) four-armed star-shaped block copolymers

pH-sensitive poly(4-vinylpyridine)-block-poly(methacrylic acid) (P4VP-b-PMAA) four-armed star-shaped block copolymers were synthesized by two-step atom transfer radical polymerization (ATRP), followed by hydrolysis of P4VP-b-poly(tert-butyl methacrylate) (P4VP-b-PtBMA). The chemical structure and molecular weight of the as-synthesized block copolymers were characterized by Fourier transform infrared spectrometry (FTIR), nuclear magnetic resonance (1H and 13C NMR), and gel permeation chromatography (GPC) determinations. The solution behavior was investigated by surface tension technique, ultraviolet visible (UV-vis) transmittance, transmission electron microscopy (TEM), dynamic light scattering (DLS), and zeta potentials measurements. The experimental results indicated that the copolymers can spontaneously assemble into spherical-shaped core-shell micelle aggregates, with a critical micelle concentration (CMC) about 200 mg L−1, hydrodynamic diameters from 90 to 210 nm, depending on the environmental pH values and compositional ratios. The transmittance measurements revealed that the block copolymers produce evident phase transition in aqueous solution at pH from 6.5 to 7.0. Zeta potential data revealed high micelle stability. The as-synthesized block copolymers are anticipated to find their applications in the realms of specific drug release, metal loading and heterogeneous catalysis. Open image in new window

Preparation of a novel polymer monolith using atom transfer radical polymerization method for solid phase extraction

In this study, a novel polymer monolith based solid phase extraction (SPE) material has been prepared by two-step atom transfer radical polymerization (ATRP) method. Firstly, employing ethylene glycol dimethacrylate (EDMA) as a cross-linker, a polymer monolith filled in a filter head has been in-situ prepared quickly under mild conditions. Then, the activators generated by electron transfer ATRP (ARGET ATRP) was used for the modification of poly(2-(dimethylamino)ethyl-methacrylate) (PDMAEMA) on the monolithic surface. Finally, this synthesized monolith for SPE was successfully applied in the extraction and enrichment of steroids. The results revealed that ATRP can be developed as a facile and effective method with mild reaction conditions for monolith construction and has the potential for preparing monolith in diverse devices.

Temperature induced micellization and aggregation of biocompatible poly (oligo(ethylene glycol)methyl ether methacrylate) block copolymer analogs in aqueous solutions

A series of well-defined block copolymers composed of di(ethylene glycol) methyl ether methacrylate (188 g/mol) and oligo(ethylene glycol) methyl ether methacrylate (300 g/mol), PMEO2MA-b-(PMEO2MA-stat-POEGMA300), were successfully synthesized at room temperature via a two-step atom transfer radical polymerization (ATRP) process using 1,1,4,7,10,10-hexamethyl triethylene tetramine (HMTETA) as the ligand. The ratio of MEO2MA/OEGMA300 in the second block controls the thermal behaviors of these copolymers. When the ratio of MEO2MA/OEGMA300 is 80/20, only one thermal transition was observed. However, two thermal transitions were observed for MEO2MA/OEGMA300 ratios of 70/30 and 0/100. We believed that the first transition was associated with the formation of micelles and the second transition corresponded to the formation of larger aggregates consisting of several preformed micelles. This hypothesis was confirmed by light scattering, where the hydrodynamic radius (Rh) of the aggregates of 70/30 and 0/100 systems increased from 48 to 95 nm and 88 to 147 nm with a corresponding increase in the Rg/Rh from 0.76 to 1.1 and 0.68 to 1.0 respectively. TEM analyses confirmed the formation of spherical particles, where the sizes of these particles increased with increasing temperatures.

Preparation of well-defined environmentally responsive polymer brushes on monolithic surface by two-step atom transfer radical polymerization method for HPLC

Well-defined poly (2-(dimethylamino) ethyl methacrylate) (PDMAEMA) brushes were successfully prepared on the monolithic surface via two-step atom transfer radical polymerization (ATRP). The polymer brushes synthesized by the second-step ATRP were based on the active bromic groups resulting from poly (ethylene glycol dimethacrylate) (pEDMA) monolith which was prepared at room temperature by the first-step ATRP. Element analysis was used to monitor the grafting process at different reaction times. Each step of preparation was characterized by scanning electron microscope, infrared spectrum and mercury intrusion porosimetry. Employment of PDMAEMA grafted monolith as the stationary phase for chromatographic analysis of steroids demonstrated that the PDMAEMA brushes possessed both pH- and salt-responsive properties. Noticeably, it has been found that the chain length of PDMAEMA brushes could influence the retention behavior of steroids due to the controllability of ATRP, which proposed an interesting alternative to modulate retention in HPLC. This is the first application of PDMAEMA brushes grafted monolith by two-step ATRP method for constructing responsive surface in HPLC and it might exploit a new path for widening the monolith application in various fields.

Water-soluble dendritic-linear triblock copolymer-modified magnetic nanoparticles: preparation, characterization and drug release properties

One route has been employed to prepare dendritic-linear block copolymer modified superparamagnetic iron oxide nanoparticles (SPIONs), which consist of a Fe3O4 magnetic nanoparticle core and a dendritic-linear block copolymer, the focal point polyamidoamine-type dendron-b-poly(2-dimethylaminoethyl methacrylate)-b-poly(N-isopropylacrylamide) (PAMAM-b-PDMAEMA-b-PNIPAM) shell by two-step atom transfer radical polymerization (ATRP). Firstly, Fe3O4 nanoparticles were prepared by a high-temperature solution phase reaction in the presence of iron(III) acetylacetonate [Fe(acac)3], oleic acid and oleylamine. Then propargyl focal point PAMAM-type dendron (generation 2.0, denoted as propargyl-D2.0) with four carboxyl acid end groups as a cap displaced the oleic acid and oleylamine on the surfaces. Subsequently, an initiator for ATRP was introduced onto the propargyl-D2.0-modified Fe3O4 nanoparticle surfaces via click chemistry with 2′-azidoethyl-2-bromoisobutylate (AEBIB). PDMAEMA and PNIPAM were grown gradually from nanoparticle surfaces using two-step copper-mediated ATRP. Finally, a crosslinking reaction between PDMAEMA block with 1,2-bis(2-iodoethoxy)ethane (BIEE) was used to stabilize the nanoparticles and reverse aggregation. The modified nanoparticles were subjected to detailed characterization using FT-IR, DLS, XRD and TGA. Magnetization measurements confirmed the characteristic superparamagnetic behavior of all magnetic nanoparticles under room temperature. In addition, doxorubicin (DOX) as an anticancer drug model was loaded into the dendritic-linear block copolymer shell of the modified nanoparticles, and subsequently the drug release was performed in phosphoric acid buffer solution (pH 7.4) at 25 °C or 37 °C. The results verify that dendritic-linear block copolymer-modified nanoparticles as a drug carrier possess thermosensitive drug release behaviors. Furthermore, a methyl tetrazolium (MTT) assay of DOX-loaded dendritic-linear block copolymer-modified nanoparticles against Hela cells was evaluated. The results show that the modified nanoparticles can be used for drug delivery.

Functional Polymeric Nanoobjects by Cross-Linking Bulk Self-Assemblies of Poly(tert-butyl acrylate)-block-poly(glycidyl methacrylate)

We report the bulk self-assembly of diblock copolymer poly(tert-butyl acrylate)-block-poly(glycidyl methacrylate) (PtBA-b-PGMA) with the PGMA that bears many epoxy groups as a cross-linkable segment and the PtBA as a hydrolyzable segment. The PtBA-b-PGMA block copolymers of a different composition were synthesized by two-step atom transfer radical polymerization (ATRP). After bulk self-assembly, the morphologies of microphase separation of the block copolymers were studied with small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). The results showed that with decrease of volume ratio of the PGMA segments the PtBA-b-PGMA self-assembled into lamellae, cylinders, and spheres with the dispersed PGMA domains. The epoxy groups in the PGMA domains were cross-linked by exposing the microphase-separated films into an atmosphere of either ethylenediamine (EDA) or propargylamine (PA). Then the bulk materials were dispersed into the good solvent of PtBA to generate the polymeric nanoobjects ...