UV-initiated Copolymerization Research Articles

Mussel Foot Protein Inspired Tape-Type Adhesive with Water-Responsive, High Conformal, Tough, and On-Demand Detachable Adhesion to Wet Tissue.

Wet adhesion is highly demanded in noninvasive wound closure, tissue repair, and biomedical devices, but it is still a big challenge for developing biosafe and tough wet bioadhesives due to low or even nonadhesion in the wet state for conventional adhesives. Inspired by the wet-adhesion-contributing factors of mussel foot proteins, a water-responsive dry robust tissue adhesive PAGU tape is made with thickness of <0.5mm through fast UV-initiated copolymerization of acrylic acid (AA), gelatin (Gel), and hexadecenyl-1,2-catechol (UH). The tape shows strong cohesive mechanical properties and strong interfacial adhesion bonds. Upon application onto wet tissue, the adhesive tape can conform to the tissue, quickly dry tissue surface through absorbing surface/interfacial water and then allows formation of interfacial bonding with a high interfacial toughness of ≈818Jm-2 . Furthermore, it can be readily detached by treating with aq. urea solution. A highly efficient avenue is provided here for producing conformable, tough, and easy detachable wet bioadhesive tapes.

Preparation of polyacrylate/silica membranes for fuel cell application by in situ UV polymerization

The development of proton conductive polyacrylate membranes based on acrylonitrile, sodium 4-vinylbenzenesulfonate, acrylic acid, ethylene glycol dimethacrylate and hybrid polyacrylate/silica membranes is reported in this article. Polyacrylate membranes were synthesized via UV-initiated copolymerization; for the synthesis of polyacrylate/silica membranes 3-methacryloxypropyl trimethoxysilane-based sol–gel system was introduced into the polymerizing mixture.

Flocculation of emulsified oily wastewater by using functional grafting modified chitosan: The effect of cationic and hydrophobic structure

In this work, modified chitosan flocculants (MCS) was synthesized by using chitosan (CS), acrylamide, cationic monomers and hydrophobic monomers via low-pressure UV-initiated copolymerization. The flocculation performance of MCS was evaluated in emulsified oily wastewater treatment. The effect of cationic and hydrophobic structure on oil removal was studied, and the interactions between these functional groups and the components in oil were also analyzed. Results suggested that MCS flocculants exhibited excellent oil removal efficiency in a wide pH range (2.0‒10). The flocculation efficiency of 91 % was achieved at the dosages of 0.6 mL/L (6 mg/L). During pH of 2.0-10, the optimal cationic and hydrophobic monomer was DMC and VT, respectively. Silane groups were favorable for oil removal than the other hydrophobic structures. The cationic groups expanded the optimal pH range of MCS in flocculation, whereas hydrophobic groups considerably reduced the dosage of MCS. The experimental results showed that alkane, cyclic aromatic hydrocarbon compounds in oil can be easily removed by using MC4, whereas cycloalkanes compounds was effectively removed by MC6 and MC7 because of preferable demulsification capacity, and the hydrophobic interaction, interfacial adsorption and electrostatic attraction played the dominant in flocculation. Thus, the synthesized MCS is favorable for emulsified oily wastewater treatment.

H2O2/UV-Initiated Copolymerization of Acrylamide and Dimethyl Diallyl Ammonium Chloride: Characterization and Flocculation Performance

The cationic polyacrylamide flocculant P(AM-DMDAAC) is prepared by copolymerizing acrylamide (AM) and dimethyl diallyl ammonium chloride (DMDAAC) initiated by H2O2 under UV irradiation conditions. The structural features and thermal stability of P(AM-DMDAAC) are characterized via infrared spectroscopy, thermogravimetry/differential scanning calorimetry, and proton nuclear magnetic resonance spectroscopy. The effects of multiple factors, including monomer concentration, mass monomer ratio, illumination time, initiator H2O2 concentration, solution pH, illumination intensity, and urea concentration, on the intrinsic viscosity of P(AM-DMDAAC) are studied. The optimum preparation conditions are found to be 30% monomer concentration, 1:4 mass monomer ratio, 0.5‰ initiator concentration, 5.5 pH, 30 min illumination time, 1800 uW/cm2 illumination intensity, and 0.5% urea concentration. Under optimal conditions, the intrinsic viscosity of P(AM-DMDAAC) reaches 18.31 dL/g, which corresponds to a molecular weight of 9.6 × 10 6. Sludge dewatering experiments show that P(AM-DMDAAC) exhibits superior flocculating performance compared with other flocculants.

A super-stretchable, self-healing and injectable supramolecular hydrogel constructed by a host-guest crosslinker.

Supramolecular hydrogels based on host-guest interactions have drawn considerable attention due to their unique properties and promising applications. However, it is still a great challenge to construct supramolecular hydrogels that simultaneously achieve mechanical strength, processability, and biocompatibility. Herein, we present a rational design of a "supramolecular crosslinker" approach to fabricate a new host-guest hydrogel with super-stretchability, self-healing, and injectable properties and excellent biocompatibility. The star-shaped supramolecular crosslinker is formed by the host-guest interactions between octa-cyclodextrin polyhedral oligomeric silsesquioxane (OCDPOSS) and acrylamide-modified adamantane (Ad-AAm). Supramolecular hydrogels can be briefly prepared by UV-initiated copolymerization of acrylamide and supramolecular crosslinkers. Supramolecular hydrogels present impressive mechanical properties due to rigid POSS as the core of the supramolecular crosslinker. Moreover, multivalent host-guest interactions improve the ductility, rapid self-healing and injectable ability of these hydrogels. Simultaneously, these supramolecular hydrogels possess good biocompatibility and can be utilized as carriers for the sustained release of hydrophobic drugs. Thus, such supramolecular hydrogels will have potential applications for tissue engineering and drug delivery systems.

Removal of emulsified oil from water using hydrophobic modified cationic polyacrylamide flocculants synthesized from low-pressure UV initiation

Abstract This study investigated a hydrophobic-modified cationic polyacrylamide (PAMP) synthesized through low-pressure UV-initiated copolymerization by using monomers of acrylamide (AM), diallyl dimethyl ammonium chloride aqueous solution (DADMAC), and dodecyl polyglucoside (DPL) to effectively remove emulsified oil from water. Various analytical methods were used to characterize the microstructure of PAMP, including Fourier transform infrared spectroscopy (FTIR), unclear magnetic resonance (13C NMR and 1H NMR), and thermal gravimetric and differential analysis (TG-DTA). Results confirmed that cationic and hydrophobic monomers were successfully grafted onto the molecular chain of the PAMP. Furthermore, the flocculation efficiency of PAMP was evaluated and optimized in emulsified oily wastewater treatment. PAMP exhibited satisfactory emulsified oil removal efficiency, and optimal oil and turbidity removal efficiencies of 94.5–98.6% and 95.1–98.9% were achieved with DADMAC content of 40%, DPL content of 30%, dosage of 8.5–9 mg/L, pH of 6–8, rapid stirring speed of 400 rpm, rapid stirring time of 35 min, slow stirring time of 15 min, and standing time of 25 min. Moreover, charge neutralization and hydrophobic association interaction dominate the emulsion breaking in oily wastewater flocculation.

Synthesis of cellulose-based double-network hydrogels demonstrating high strength, self-healing, and antibacterial properties

Novel antibacterial double-network (DN) hydrogels with superior mechanical and self-healing properties are developed via the UV-initiated copolymerization of polyacrylic acid (PAA)-grafted quaternized cellulose (QCE) and polyvinyl alcohol (PVA). The QCE functioned as an antibacterial agent, resulting in excellent antibacterial capability (antibacterial rate >93%). The hydrogels are thus protected from microbial attack in natural environments, prolonging their lifetime. The PVA functioned as a physical cross-linker, resulting in superior mechanical properties. At PVA and QCE contents of 8% and 1.5%, respectively, the strain and stress at break of hydrogel were 465.37% and 1.13MPa, respectively. The hydrogel maintained good self-healing properties owing to ionic bonding between the ferric ions and carboxylic groups, and hydrogen bonding between the PVA molecules. The hydrogel was responsive to pH; its water-holding ability could be controlled by changing the pH. The material is simply prepared and used. Hydrogels with such excellent properties could be applied in various biomedical fields.

Synthesis of Epoxy-Functionalized Micro-Zone Plates by UV-Initiated Copolymerization

As microfluidic systems transition from research tools to disposable clinical devices, new substrate materials are need to meet both the regulatory requirement as well as the economics of disposable devices. In this paper, a commercial ultraviolet (UV)-curiable material (bisphenol A based epoxy acrylate, BABEA) was introduced as a new manufacturing material for facile fabrication of epoxy-functionalized microfluidic devices by UV-initiated copolymerization. X-ray photoelectron spectroscope (XPS) results indicated the existence of epoxy groups on the surface of poly (BABEA-co-GMA), which allowed for binding protein through an epoxy-amino group reaction. Poly (BABEA-co-GMA) is highly transparent in visible range, and of high replication fidelity. A fabrication procedure was proposed for manufacturing BABEA based epoxy-functionalized micro-zone plates. The fabrication procedure was very simple; obviating the need of micromachining equipments, wet etching or imprinting techniques. To evaluate the BABEA based epoxy-functionalized micro-zone plates, α-fetoprotein (AFP) antibody was immobilized onto the capture zone for chemiluminescent (CL) detection in a non-competitive immune response format. The proposed AFP immunoaffinity micro-zone plate was demonstrated as a low cost, flexible, homogeneous and stable assay for AFP.

Synthesis of Hydrophilic Epoxy-Functionalized Films by UV-Initiated Copolymerization

Bisphenol A based epoxy acrylate (BABEA), a commercial ultraviolet (UV)-curiable material, was introduced as a new manufacturing material for facile fabrication of epoxy-functionalized films through UV-initiated copolymerization using glycidyl methacrylate (GMA) as the functional monomer. X-ray photoelectron spectroscope (XPS) results indicated the existence of epoxy groups on the surface of the poly (BABEA-co-GMA), which allowed for binding protein through an epoxy-amino group reaction. The contact angel results indicated the poly (BABEA-co-MMA) is hydrophilic, which avoided nonspecific adsorption of biological species. Bovine serum albumin (BSA) was successfully immobilized on the poly (BABEA-co-GMA) films by using the introduced epoxy groups effectively. This makes it possible to extend the application of such films in the fields of bio-separations and bio-recognitions.

UV-curable pressure-sensitive adhesives derived from functionalized soybean oils and rosin ester

Functionalized plant oils such as epoxidized soybean oil (ESO) are widely used in plastic industries as additives and are available for more value-added applications. Pressure-sensitive adhesive (PSA) derived from petroleum feedstocks has a huge market ranging from tapes to packaging. Here we show a sustainable PSA derived from ESO/dihydroxyl soybean oil (DSO)/rosin ester (Sylvalite) via UV-initiated copolymerization. The ether crosslinks derived from cationic polymerization of ESO and copolymerization between ESO and DSO (or rosin ester) were demonstrated using 1H NMR, 2D 1H–1H COSY NMR, electrospray ionization mass spectrometry and thermal analyses (differential scanning calorimetry and thermogravimetric analysis). The PSA was formulated by modulating the ratio of ESO/DSO/rosin ester to achieve high performance. At a UV dose of 5.1–5.4 J cm−2 and 0.3–3% (w/w) of a photoinitiator, i.e. [4-(2-hydroxy-1-tetradecyloxy)-phenyl]phenyliodonium hexafluoroantimonate, the PSA at a ratio (by weight) of 1:1:0.7 (ESO/DSO/rosin ester) recorded the highest peel and loop tack strength, which was comparable to a commercial PSA, Scotch Magic Tape, and showed much stronger shear strength (>30 000 min) than the commercial tape (10 000 min). The high-shear rheological behavior and excellent thermal stability of the PSA were also demonstrated. © 2012 Society of Chemical Industry

Methacrylate-based monolithic layers for planar chromatography of polymers

A series of macroporous monolithic methacrylate-based materials was synthesized by in situ free radical UV-initiated copolymerization of functional monomers, such as glycidyl methacrylate (GMA), butyl methacrylate (BuMA), 2-aminoethyl methacrylate (AEMA), 2-hydroxyethyl methacrylate (HEMA) and 2-cyanoethyl methacrylate (CEMA), with crosslinking agent, namely, ethylene glycol dimethacrylate (EDMA). The materials obtained were applied as the stationary phases in simple and robust technique – planar chromatography (PLC). The method of separation layer fabrication representing macroporous polymer monolith bound to the specially prepared glass surface was developed and optimized. The GMA–EDMA and BuMA–EDMA matrixes were successfully applied for the separation of low molecular weight compounds (the mixture of several dies), as well as poly(vinylpyrrolidone) and polystyrene homopolymers of different molecular weights using reversed-phase mechanism. The materials based on copolymers AEMA–HEMA–EDMA and CEMA–HEMA–EDMA were used for normal-phase PLC separation of 2,4-dinitrophenyl amino acids and polystyrene standards.

Poly[hydroxyethyl acrylate-co-poly(ethylene glycol) diacrylate] Monolithic Column for Efficient Hydrophobic Interaction Chromatography of Proteins

Rigid poly[hydroxyethyl acrylate-co-poly(ethylene glycol) diacrylate] monoliths were synthesized inside 75 mum i.d. capillaries by one-step UV-initiated copolymerization using methanol and ethyl ether as porogens. The optimized monolithic column was evaluated for hydrophobic interaction chromatography (HIC) of standard proteins. Six proteins were separated within 20 min with high resolution using a 20 min elution gradient, resulting in a peak capacity of 54. The effect of gradient rate and initial salt concentration on the retention of proteins were investigated. Mass recovery was found to be greater than 96%, indicating the biocompatibility of this monolith. The monolith was mechanically stable and showed nearly no swelling or shrinking in different polarity solvents. The preparation of this in situ polymerized acrylate monolithic column was highly reproducible. The run-to-run and column-to-column reproducibilities were less than 2.0% relative standard deviation (RSD) on the basis of the retention times of protein standards. The performance of this monolithic column for HIC was comparable or superior to the performance of columns packed with small particles.

Pore-filled nanofiltration membranes based on poly(2-acrylamido-2-methylpropanesulfonic acid) gels

Strong polyacid gel-filled membranes have been prepared by UV-initiated copolymerization of 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and N, N′-methylenebisacrylamide within the pores of a microporous polypropylene (PP) substrate. These poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) gel-filled membranes were readily prepared with predictable amounts of the incorporated gel polymer (mass gain, MG) provided that threshold values of the degree of cross-linking and monomer concentration were exceeded. Most of the membranes showed large dimensional changes, particularly in their thickness on incorporation of the PAMPS. These changes were related to the amount of PAMPS incorporated into the membranes. In order to determine the polymer volume fractions of the incorporated gels, the partial specific volume of PAMPS (0.575 cm 3/g) was obtained from density measurements using pycnometry. As a result of increase in thickness (volume) of the membranes, the polymer volume fractions of the PAMPS pore-filling gels were limited to values between 0.01 and 0.06, relatively low values compared to values achieved with other gel-filled membranes based on the same substrate. The Darcy permeability of PAMPS gel-filled membranes exhibits a typical relationship with polymer volume fraction, but the absolute values obtained are much lower than those of other gel-filled membranes previously studied. The lower permeability could be attributed to tightly bound water molecules along polymer chains, which effectively enlarges the hydrodynamic size of polymer chains and narrows the channels for water transport. Using the sphere model based on the Odijk's theory of semidilute polyelectrolyte solutions, the Darcy permeability of PAMPS gel-filled membranes could be calculated with good precision.