Synthesis and modification of supports with an alkylamine and their use in albumin adsorption

The morphological effect of polymeric networks (R) modified with terminal amino groups was studied on the adsorption of bovine serum albumin (BSA). Networks of ethylene glycol dimethacrylate and 2‐hydroxyethyl methacrylate [poly (EGDMA‐co‐HEMA)] were synthesized by suspension polymerization, using different EGDMA contents and agitation speeds. These matrices were characterized by FTIR, mercury intrusion porosimetry, SEM, and swelling degree. The increase of the EGDMA concentration led to the formation of networks with the highest crosslinking degree and porosity. An earlier phase separation yielded a higher aggregation of rigid microspheres, also forming stable pore systems. The increase in coalescence frequency, together with the impeller speed, and the decrease of the stabilizer molecules led to an increment in drop size. Large fused aggregates of microspheres were formed with additional loss of small pores as the stirring was increased, attaining also a higher pore volume (V_p) and a slight decrease of the surface area. Once characterized, networks were activated with butanediolglycidyl ether (BDGE), and then reacted with hexamethylenediamine (HMDA) through coupling reaction. Only the R‐BDGE‐HMDA networks synthesized with the highest EGDMA content and agitation speed showed BSA adsorption. Their base matrices exhibited a V_p higher than 1.4 mL/g, which allows easier protein diffusion into the support. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 2557–2566, 2008     

Preparation of hollow composite spheres with raspberry‐like structure based on hydrogen‐bonding interaction

The hollow composite spheres with a raspberry‐like structure were prepared by a self‐assemble heterocoagulation based on the inter‐particle hydrogen‐bonding interaction between the amide groups of hollow poly (N,N′‐methylenebisacrylamide‐co‐N‐isopropyl acrylamide) (P(MBA‐co‐NIPAAm)) microspheres and the carboxylic acid groups of poly(ethyleneglycol dimethacrylate‐co‐methacrylic acid) (P(EGDMA‐co‐MAA)) nanoparticles, in which P(EGDMA‐co‐MAA) nanoparticle acted as the corona and the hollow P(MBA‐co‐NIPAAm) microsphere behaved as the core. The control coverage of the corona particles on the surface of hollow core microspheres of P(MBA‐co‐NIPAAm)/P(EGDMA‐co‐MAA) hollow composite sphere was studied in detail through adjustment of the mass ratio between the core and corona particles. The effect of the pH on the stability of the raspberry‐like hollow spheres was investigated. The polymer particles and the resultant heterocoagulated raspberry‐like hollow spheres were characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Copyright © 2008 John Wiley & Sons, Ltd.     

Synthesis of metal/polymer colloidal composites by the tailored deposition of silver onto porous polymer microspheres

A new colloidal silver system is presented in which a fine colloidal silver is in situ deposited onto functionalized porous poly(ethylene glycol dimethacrylate) [poly(EGDMA)] microspheres. The effectiveness of the silver deposition has been investigated through an examination of the surface characteristics of poly(EGDMA) microspheres. The result reported in this study demonstrate that the control of the surface area and surface functionality (in this study, a hydroxyl group) of poly(EGDMA) microspheres is an important factor that practically determines the degree of deposition of colloidal silver. X‐ray analysis has shown that silver nanoparticles are dispersed evenly on inner and outer surfaces and have a face center cubic phase. Preservation testing has shown that silver‐containing poly(EGDMA) microspheres have powerful antibacterial properties and, therefore, have significant potential as new preservatives. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2551–2557, 2004     

Preparation of styrene/acrylonitrile copolymer microspheres and their composites with metal particles

 Monodispersed poly(styrene-co-acrylonitrile) [P(St-co-AN)] microspheres were prepared by emulsifier-free emulsion copolymerization of St with AN. Fourier transform IR spectroscopy and elemental analysis were used to measure the content of AN in the poly(St-co-AN) microspheres. X-ray photoelectron spectroscopy (XPS) measurements indicated the presence of an AN unit on the surface of the microspheres. The combined results of the elemental analysis and the XPS measurements showed that the copolymer on the surface of the P(St-co-AN) particles was rich in AN compared with that in the interior of the particles. P(St-co-AN)–metal composite particles were prepared by chemical metal deposition. The addition of nickel could improve the distribution of cobalt on surface of the polymer microspheres. The preparation of polymer–bimetal composite particles was tried. Transmission electron microscopy and XRD were used to study the distribution and structure of the deposited metal particles. Received: 30 June 1999/Accepted in revised form: 16 September 1999     

Study of amino ligands fixation to macroporous supports and their influence on albumin adsorption

Heterogeneous networks of ethylene glycol dimethacrylate and 2‐hydroxyethyl methacrylate [poly(EGDMA‐co‐HEMA)] were synthesized by suspension polymerization using different EGDMA contents and agitation speeds. The networks were actived with epichlorhydrine (Ech) or 1,4‐butanediol diglycidyl ether (BDGE), and then hexamethylenediamine (HMDA) or ethylenediamine (EDA) were conjugated to the support by coupling reaction. Here, a higher alkyldiamine concentration and temperature, and a longer reaction time led to higher yields. Amino ligands of the support III were used to analyze their adsorption performance of bovine serum albumin (BSA) from the adsorption kinetic. A more external location of HMDA amino ligands into network led to get the maximum adsorption in a time shorter than that with EDA. Due to its bigger size, the HMDA molecule was attached mostly to the network surface between larger pores, which favored a faster protein adsorption. When derivatives containing BDGE were compared, the EDA ligand displayed a BSA retention higher than that with HMDA, because a shorter separation between the ammonium groups along the spacer arm yielded a stronger electrostatic attraction on the protein. Clearly, the balance obtained between the pores system and the reagents molecular structure used in the formation of Ech‐HMDA generated the most efficient BSA adsorption. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2009     

Synthesis of polymeric microspheres from a Merrifield resin by surface‐initiated nitroxide‐mediated radical polymerization

Polymeric microspheres were prepared from a Merrifield resin via nitroxide‐mediated radical polymerization. Polystyrene, poly(acetoxystyrene), and poly[styrene‐b‐(methyl methacrylate‐co‐styrene)], poly(acetoxystyrene‐b‐styrene), and poly(styrene‐co‐2‐hydroxyethyl methacrylate) copolymers were demonstrated to graft onto 2,2,6,6‐tetramethyl‐1‐piperidinyloxy nitroxide bound Merrifield resins. The polymerization control was enhanced both on the surface and in solution by the addition of sacrificial nitroxide. The significant increase in the particle diameter (more than a fivefold volume increase for polystyrene brushes) showed that polymer growth was not only on the surface but also within the particles, and this diameter increase could be adjusted through changes in the molecular weight of the polymers. The microspheres were characterized by elemental analysis, IR spectroscopy, particle size analysis, and optical microscopy. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 2145–2154, 2005     

Fast reversed‐phase liquid chromatographic separation of proteins by flow‐through poly(styrene‐co‐divinylbenzene) microspheres

With the explosive growth of the bioscience and biopharmaceuticals, the demand for high efficient analysis and separation of proteins is urgent. High‐performance liquid chromatography is an appropriate technology for this purpose, and the stationary phase is the kernel to the separation efficiency. In this study, flow‐through poly(styrene‐co‐divinylbenzene) microspheres characteristic of the binary pores, i.e. flow‐through pores and mesopores, were synthesized; this special porous structure would benefit the convective mass transfer while guarantee the high specific surface area. Owing to the hydrophobic nature, poly(styrene‐co‐divinylbenzene) microspheres were suitable as the reversed‐phase stationary phase for separation of proteins. For the high permeability of the poly(styrene‐co‐divinylbenzene) microspheres packed column, fast separation of the studied six proteins in ～2 min was achieved. The recoveries of studied proteins were acceptable in the range of 79.0–99.4%. The proposed column had good pH stability of 1–13 and repeatability. Moreover, the column was applied for egg white fast separation, further demonstrating its applicability for complex bio‐sample separation. The flow‐through poly(styrene‐co‐divinylbenzene) microspheres were promising for fast separation of large molecules.     

Synthesis and characterization of saccharide‐based latex particles

The synthesis of new polymer colloids based on renewable resources, such as sugar‐derived monomers, is nowadays a matter of interest. These new polymeric particles should be useful in biomedical applications, such as drug delivery, because of their assumed biodegradability. In this work, two new families of polymer latex particles, based on a sugar‐derived monomer, 3‐O‐methacryloyl‐1,2:5,6‐di‐O‐isopropylidene‐α‐D ‐glucofuranose (3‐MDG), were produced and characterized. The syntheses of poly(3‐MDG) crosslinked particles and those obtained by copolymerization with methacrylic acid (MAA), poly(3‐MDG‐co‐MAA) crosslinked particles, were prepared by surfactant‐free emulsion polymerization in a batch reactor. The average particle diameter evolutions, the effect of pH of the dispersion medium on the final average diameters, together with the microscopic and morphological analysis of the particle's surface and inner dominium, were analyzed. Poly(3‐MDG‐co‐EGDMA) stable particles were obtained by adding low amounts of initiator. The surface‐charge density of these particles corresponded to the sulfate groups coming from the initiator. In the second family of latices, poly(3‐MDG‐co‐MAA‐co‐EGDMA) particles, DCP measurements and SEM and TEM observations showed that the sizes and surface characteristics depended on the amounts of MAA and crosslinker used in the reaction mixture. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 443–457, 2006     

Adsorption of protein on the surface of thermosensitive poly(methyl methacrylate) microspheres modified with the N-(2-hydroxypropyl)methacrylamide and 2-(methacryloyloxy)ethyl phosphorylcholine moieties

A series of microspheres composed of methyl methacrylate (MMA) and N-(2-hydroxypropyl)methacrylamide (HPMA), and/or 2-(methacryloyloxy)ethyl phosphorylcholine (MPC), i.e., binary copolymer microspheres [poly(HPMA-co-MMA)_KPS and poly(HPMA-co-MMA)_ABIP] and ternary ones [poly(HPMA/MPC-co-MMA)_KPS and poly(HPMA/MPC-co-MMA)_ABIP], were prepared by emulsifier-free emulsion copolymerization using potassium peroxodisulfate (KPS) or 2,2′-azobis[2-(imidazolin-2-yl)propane] dihydrochloride (ABIP) as initiators. The decrease in ζ-potential of the polymer microspheres is caused by the addition of the HPMA and/or MPC moieties. Equilibrium water content of poly(HPMA-co-MMA)_ABIP showed a remarkable swelling change with a change in response to temperature: the hydrated conformation at 28°C and the dehydrated one at above 40°C. The adsorption of protein on the polymer microspheres also changed in response to change in temperature. The ternary polymer microspheres effectively suppressed the adsorption both of Alb and Glo, less than binary ones. A series of polymer microspheres are expected to apply as a novel drug carrier with both thermosensitive and nonthrombogenic functions. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 3349–3357, 1997     

Preparation of P(MBA‐co‐MAA)/Zr(OH)4/P(EGDMA‐co‐MAA)/TiO2 Tetra‐layer Hybrid Microspheres and the Corresponding ZrO2/TiO2 Double‐shelled Hollow Microspheres

Double‐shelled zirconia/titania (ZrO₂/TiO₂) hollow microspheres were prepared by the selective removal of the polymer components via the calcination of the corresponding tetra‐layer poly(N,N′‐methylenebisacryl amide‐co‐methacrylic acid) (P(MBA‐co‐MAA))/Zr(OH)₄/poly(ethyleneglycol dimethacrylate‐co‐methacrylic acid) (P(EGDMA‐co‐MAA))/TiO₂ hybrid microspheres. These tetra‐layer microspheres were synthesized by the combination of the distillation copolymerization of N,N(‐methylenebisacryl amide‐co‐methacrylic acid (MBA) or ethyleneglycol dimethacrylate (EGDMA) crosslinker and methacrylic acid (MAA) for the preparation of polymer core and third‐layer as well as the controlled sol‐gel hydrolysis of inorganic precursors for the construction of zirconium hydroxide (Zr(OH)₄) and titania (TiO₂) layers. The thicknesses of zirconia and titania shell‐layers were conveniently controlled via varying the feed of zirconium n‐butoxide (Zr(OBu)₄) and titanium tetrabutoxide (TBOT) during the sol‐gel hydrolysis, while the sizes of polymer layers were tuned through a multi‐stage distillation precipitation copolymerization. The structure and morphology of the resultant microspheres were characterized by transmission electron microscopy (TEM), X‐ray diffractometer (XRD), X‐ray photoelectronic spectroscopy (XPS), and thermogrametric analysis (TGA).     

Preparation and ion conductivities of the plasticized polymer electrolytes based on the poly(acrylonitrile‐ co‐lithium methacrylate)

The polymer electrolytes composed of poly(acrylonitrile‐co‐lithium methacrylate) [P(AN‐co‐LiMA)], ethylene carbonate (EC), and LiClO₄ salts have been prepared. The ion groups in the P(AN‐co‐LiMA) were found to prevent EC from crystallization through their ion–dipole interactions with the polar groups in the EC. This suppression of the EC crystallization could lead to the enhancement of the ion conductivity at subambient temperature. The polymer electrolytes based on the PAN ionomer with 4 mol % ion content exhibited ion conductivities of 2.4 × 10⁻⁴ S/cm at −10°C and 1.9 × 10⁻³ S/cm at 25°C by simply using EC as a plasticizer. In the polymer electrolytes based on the PAN ionomer, ion motions seemed to be coupled with the segmental motions of the polymer chain due to the presence of the ion–dipole interaction between the ion groups in the ionomer and the polar groups in the EC, while the ion transport in the PAN‐based polymer electrolytes was similar to that of the liquid electrolytes. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 247–252, 1999     

Block copolymer mediated synthesis of amphiphilic gold nanoparticles in water and an aqueous tetrahydrofuran medium: An approach for the preparation of polymer–gold nanocomposites

The synthesis of polymer‐matrix‐compatible amphiphilic gold (Au) nanoparticles with well‐defined triblock polymer poly[2‐(N,N‐dimethylamino)ethyl methacrylate]‐b‐poly(methyl methacrylate)‐b‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate] and diblock polymers poly(methyl methacrylate)‐b‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate], polystyrene‐b‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate], and poly(t‐butyl methacrylate)‐b‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate] in water and in aqueous tetrahydrofuran (tetrahydrofuran/H₂O = 20:1 v/v) at room temperature is reported. All these amphiphilic block copolymers were synthesized with atom transfer radical polymerization. The variations of the position of the plasmon resonance band and the core diameter of such block copolymer functionalized Au particles with the variation of the surface functionality, solvent, and molecular weight of the hydrophobic and hydrophilic parts of the block copolymers were systematically studied. Different types of polymer–Au nanocomposite films [poly(methyl methacrylate)–Au, poly(t‐butyl methacrylate)–Au, polystyrene–Au, poly(vinyl alcohol)–Au, and poly(vinyl pyrrolidone)–Au] were prepared through the blending of appropriate functionalized Au nanoparticles with the respective polymer matrices {e.g., blending poly[2‐(N,N‐dimethylamino)ethyl methacrylate]‐b‐poly(methyl methacrylate)‐b‐poly[2‐(N,N‐dimethylamino)ethyl methacrylate‐stabilized Au with the poly(methyl methacrylate)matrix only}. The compatibility of specific block copolymer modified Au nanoparticles with a specific homopolymer matrix was determined by a combination of ultraviolet–visible spectroscopy, transmission electron microscopy, and differential scanning calorimetry analyses. The facile formation of polymer–Au nanocomposites with a specific block copolymer stabilized Au particle was attributed to the good compatibility of block copolymer coated Au particles with a specific polymer matrix. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1841–1854, 2006     

Surface modification of gold nanoparticles with polyhedral oligomeric silsesquioxane and incorporation within polymer matrices

A new approach to achieve polymer‐mediated gold ferromagnetic nanocomposites in a polyhedral oligomeric silsesquioxane (POSS)‐containing random copolymer matrix has been developed. Stable and narrow distributed gold nanoparticles modified by 3‐mercaptopropylisobutyl POSS to form Au‐POSS nanoparticles are prepared by two‐phase liquid‐liquid method. These Au‐POSS nanoparticles form partial particle aggregation by blending with poly(n‐butyl methacrylate) (PnBMA) homopolymer because of poor miscibility between Au‐POSS and PnBMA polymer matrix. The incorporation the POSS moiety into the PnBMA main chain as a random copolymer matrix displays well‐dispersed gold nanoparticles because the POSS‐POSS interaction enhances miscibility between gold nanoparticles and the PnBMA‐POSS copolymer matrix. This gold‐containing nanocomposite exhibits ferromagnetic phenomenon at room temperature. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 811–819, 2009     

Raft polymerization of N,N‐dimethylacrylamide from magnetic poly(2‐hydroxyethyl methacrylate) microspheres to suppress nonspecific protein adsorption

Nonspecific interaction is a key parameter affecting the efficiency of proteins, nucleic acids or cell separation. Currently, many approaches to introduce antifouling properties to materials have been developed. Among these, surface modification with polymer brushes plays a prominent role. The aim of this study was to synthesize new magnetic microspheres grafted with poly(N,N‐dimethylacrylamide) (PDMA) that resist nonspecific protein adsorption. Monodisperse macroporous poly(2‐hydroxyethyl methacrylate) (PHEMA) microspheres, 4 μm in size, were synthesized by a multiple swelling polymerization method. To render the microspheres magnetic, iron oxide was precipitated inside the microsphere pores. Functional carboxyl groups, introduced by the hydrolysis of the 2‐(methacryloyl)oxyethyl acetate (HEMA‐Ac) comonomer, were used to react with propargylamine, followed by coupling of a chain transfer agent via an azide‐alkyne click reaction. PDMA was grafted from the PHEMA microspheres using reversible addition‐fragmentation chain transfer polymerization (RAFT), resulting in surfaces with more than 81 wt % PDMA attached. The successful modification of the microspheres was confirmed by XPS. The magnetic microspheres grafted with PDMA showed excellent antifouling properties as tested in bovine serum protein solutions. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 1036–1043     

Mechanism of the formation of stable microspheres by precipitation copolymerization of styrene and divinylbenzene

Fully crosslinked, stable poly(styrene‐co‐divinylbenzene) microspheres were prepared by precipitation polymerization, and a new mechanism is proposed, based on the morphology, circularity, and specific surface area. Once the stable particles were generated by aggregation of the primary nucleus particles, they grew in size by absorbing oligomeric species without generating substantial pores. The investigation was carried out characterizing the particles in the polymerization time and in various concentrations of the polymerization ingredients. Particle size continuously grew, but the uniformity and circularity of the microspheres were reduced with polymerization time because of the higher reactivity of divinylbenzene. The measured specific surface areas of the microspheres all were less than 10 m²/g, which showed good agreement with calculated values under an assumption of no pores on the surface of the microspheres. Thus, the specific surface area of the microspheres supported the proposed mechanism. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3967–3974, 2004     

One‐stage synthesis of narrowly dispersed polymeric core‐shell microspheres

A method of one‐stage soap‐free emulsion polymerization to synthesize narrowly dispersed core‐shell microspheres is proposed. Following this method, core‐shell microspheres of poly(styrene‐co‐4‐vinylpyridine), poly(styrene‐co‐methyl acrylic acid), and poly[styrene‐co‐2‐(acetoacetoxy)ethyl methacrylate‐co‐methyl acrylic acid] are synthesized by one‐stage soap‐free emulsion polymerization of a mixture of one or two hydrophobic monomers and a suitable hydrophilic monomer in water. The effect of the molar ratio of the hydrophobic monomer to the hydrophilic one on the size, the core thickness, and the shell thickness of the core‐shell microspheres is discussed. The molar ratio of the hydrophobic and hydrophilic monomers and the hydrophilicity of the resultant oligomers of the hydrophilic monomer are optimized to synthesize narrowly dispersed core‐shell microspheres. A possible mechanism of one‐stage soap‐free emulsion polymerization to synthesize core‐shell microspheres is suggested and coagglutination of the oligomers of the hydrophilic monomers on the hydrophobic core is considered to be the key to form core‐shell microspheres. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 1192–1202, 2008     

Synthesis of Nanocomposites from Pd0 and a Hyper‐Cross‐Linked Functional Resin Obtained from a Conventional Gel‐Type Precursor

Hyper‐cross‐linked resins stemming from a gel‐type poly‐chloromethylated poly(styrene‐co‐divinylbenzene) resin (GT) have been investigated by a multi‐methodological approach based on elemental analysis, scanning electron microscopy, X‐ray microanalysis, and solvent absorption. The hyper‐cross‐linking of the parent resin was accomplished by Friedel–Crafts alkylation of the phenyl rings of the resins with the chloromethyl groups. This produced a permanent pore system comprising both micropores (<2.0 nm in diameter) and mesopores (2.2 nm). The chloromethyl groups that did not react in the hyper‐cross‐linking step were transformed into methylmercaptan groups and the latter were then converted into sulfonic groups by oxidation with hydrogen peroxide. By this procedure the extensive permanent porosity of the parent unsulfonated hyper‐cross‐linked polymer (HGT) was retained by the sulfonated polymer (HGTS). The final exchange capacity of HGTS was determined to be 0.36 mmol g^?1. HGTS was easily metalated with Pd^II and the subsequent reduction of the metal centers with either aqueous sodium borohydride, formaldehyde, or dihydrogen produced three Pd⁰/HGTS nanocomposites. The metal nanoparticles had diameters in the 1–6 nm range for all the nanocomposites, as determined by TEM, but with somewhat different distributions. When formaldehyde was used, more than 90 % of the nanoparticles were less than 3 nm and their radial distribution throughout the polymer beads was quite homogeneous. These findings show that with this reducing agent the metal nanoparticles are generated within the pore system of the polymer matrix, hence their size is controlled by the dimensions of the pores of the polymeric support.     

Synthesis,characterization and catalytic performance of core‐shell structure magnetic Fe3O4/P(GMA‐EGDMA)‐NH2/HPG‐COOH‐Pd catalyst

A strategy has been developed for the synthesis, characterization and catalysis of magnetic Fe₃O₄/P(GMA‐EGDMA)‐NH₂/HPG‐COOH‐Pd core‐shell structure supported catalyst. The P(GMA‐EGDMA) polymer layer was coated on the surface of hollow magnetic Fe₃O₄ microspheres through the effect of KH570. The core‐shell magnetic Fe₃O₄/P(GMA‐EGDMA) modified by ‐NH₂ could be grafted with HPG. Then, the hyperbranched glycidyl (HPG) with terminal ‐OH were modified by ‐COOH and adsorbed Pd nanoparticles. The hyperbranched polymer layer not only protected the Fe₃O₄ magnetic core from acid–base substrate corrosion, but also provided a number of functional groups as binding sites for Pd nanoparticles. The prepared catalyst was characterized by UV–vis, TEM, SEM, FTIR, TGA, ICP‐OES, BET, XRD, DLS and VSM. The catalytic tests showed that the magnetic Fe₃O₄/P(GMA‐EGDMA)‐NH₂/HPG‐COOH‐Pd catalyst had excellent catalytic performance and retained 86% catalytic efficiency after 8 consecutive cycles.     

Control of porosity in hierarchically porous polymers derived from hyper‐crosslinked block polymer precursors

We report an approach to control the pore characteristics of hierarchically porous polymers (HPPs) containing micropores in a well‐defined 3D continuous mesoporous framework, by the hyper‐crosslinking reaction of a crosslinked block polymer precursor polylactide‐b‐poly(vinylbenzyl chloride‐co‐styrene‐co‐divinylbenzene) (PLA‐b‐P(VBzCl‐co‐S‐co‐DVB)) consisting of bicontinuous PLA and P(VBzCl‐co‐S‐co‐DVB) microdomains. We investigated the hyper‐crosslinking reaction of P(VBzCl‐co‐S‐co‐DVB)s synthesized by reversible addition‐fragmentation chain transfer (RAFT) copolymerization, and then examined the effect of VBzCl, S, DVB, and polylactide macrochain transfer agent (PLA‐CTA) contents in the polymerization mixture on the pore characteristics of the HPPs. We demonstrate that while the VBzCl content responsible for the hyper‐crosslinking reaction primarily governs microporosity, the DVB content has a strong influence on the mesopore structure, as it determines the onset of the gelation of the polymerization mixture, which arrests the emerging disordered bicontinuous morphology induced by the polymerization‐induced microphase separation process. Because the PLA microdomains template the percolating mesoporous space, mesoporosity was mainly controlled by the PLA‐CTA contents. The synergistic combination of hyper‐crosslinking and block polymer self‐assembly in the HPP formation provided a highly reinforced mesoporous framework, stable against pore collapse, and interconnected mesopores. These facilitated diffusion to the microporous surfaces, suggesting its utility for advanced absorbents and catalytic supports. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56, 900–913     

Photochemical construction of nanoporous polymer microspheres in Cu/Cu2O nanoparticle suspensions

Taking the poly(styrene-co-acrylamide) (P(St-AM)) as a model material, a novel two-step photochemical method was introduced to construct nanoporous polymer microspheres at room temperature. Under ultraviolet light irradiation, suspensions composed of Cu/Cu₂O nanoparticles were first prepared in an alcohol solution of acetylacetonate and benzophenone. Subsequently, the monomers were photopolymerized around the nanoparticles in the suspension-added precursor solution to form polymer–nanoparticle composite microspheres. Nanoporous polymer microspheres could then be obtained by removing the particles with acid. The products had been investigated by XRD, SEM, TEM, IR, DSC, and BET. Results showed the typical microspheres had diameters of 200~300?nm, and the specific areas and pore volume regularly varied with the quantity of the suspensions. By the optimum control, porous P(St-AM) microspheres with average pore size of 5.7?nm, pore volume of 0.18?cm³/g, and specific surface area of 123.54?m²/g could be obtained. The method represents a new, easily manipulated, cost-effective, and safe route for preparation of porous polymer microspheres using inorganic porogens.