Showing papers on "Methacrylic acid published in 2008"
TL;DR: Electrosteric stabilization provides the best resistance to changing electrolyte conditions likely to be encountered in real groundwater aquifers, and may provide transport distances of 10s to 100s of meters in unconsolidated sandy aquifer at injection velocities used for emplacement.
Abstract: The surfaces of nanoscale zerovalent iron (NZVI) used for groundwater remediation must be modified to be mobile in the subsurface for emplacement. Adsorbed polymers and surfactants can electrostatically, sterically, or electrosterically stabilize nanoparticle suspensions in water, but their efficacy will depend on groundwater ionic strength and cation type as well as physical and chemical heterogeneities of the aquifer material. Here, the effect of ionic strength and cation type on the mobility of bare, polymer-, and surfactant-modified NZVI is evaluated in water-saturated sand columns at low particle concentrations where filtration theory is applicable. NZVI surface modifiers include a high molecular weight (MW) (125 kg/mol) poly(methacrylic acid)-b-(methyl methacrylate)-b-(styrene sulfonate) triblock copolymer (PMAA-PMMA-PSS), polyaspartate which is a low MW (2−3 kg/mol) biopolymer, and the surfactant sodium dodecyl benzene sulfonate (SDBS, MW = 348.5 g/mol). Bare NZVI with an apparent ζ-potential of −3...
506 citations
TL;DR: A new approach for the synthesis of fluorescent and water-soluble Ag nanoclusters is reported, using the common polyelectrolyte poly(methacrylic acid) as the template.
305 citations
TL;DR: In this article, the homopolymers of methacrylic acid (MAA), MEOMA, diethyleneglycol methyl ether methacrylate (MEO2MA), OEGMA475 and OEGma1100 were synthesized with various chain lengths via reversible addition fragmentation chain transfer (RAFT) polymerization.
Abstract: Homopolymers of methacrylic acid (MAA), monoethyleneglycol methyl ether methacrylate (MEOMA), diethyleneglycol methyl ether methacrylate (MEO2MA), oligo(ethyleneglycol) methyl ether methacrylate (OEGMA475 and OEGMA1100) and oligo(ethyleneglycol) ethyl ether methacrylate (OEGEMA246) were synthesized with various chain lengths via reversible addition fragmentation chain transfer (RAFT) polymerization. The homopolymers of MAA, MEOMA and OEGMA1100 did not show any cloud point (CP) in the range of 0–100 °C, whereas at a pH value of 7, the CPs were found to be 20.6, 93.7, and 20.0 °C for p(MEO2MA), p(OEGMA475) and p(OEGEMA246), respectively, with an initial monomer to initiator ratio of 50. Furthermore, statistical copolymer libraries of MAA with OEGMA475 and OEGMA1100 were prepared. The cloud points of the random copolymers of MAA and OEGMA475 were found to be in the range of 20–90 °C; surprisingly, even though the homopolymers of MAA and OEGMA1100 did not exhibit any LCST behavior, the copolymers of these monomers at certain molar ratios (up to 40% OEGMA1100) revealed a double responsive behavior for both temperature and pH. Finally, the cloud points were found to be in the range of 22–98 °C, measured at pH values of 2, 4, and 7, while no cloud point was detected at pH 10. © Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7138–7147, 2008
227 citations
TL;DR: In this article, a composite of multiwalled carbon nanotubes (MWNTs) and molecularly imprinted polymers (MIPs) was prepared by using dopamine (DA) as a template molecule.
Abstract: A novel composite of multiwalled carbon nanotubes (MWNTs) and molecularly imprinted polymers (MIPs) was prepared by using dopamine (DA) as a template molecule. Selective copolymerization of methacrylic acid and trimethylolpropane trimethacrylate (copoly(MAA-co-TRIM)) in the presence of DA was achieved at the vinyl group functionalized MWNT surface. Vinyl groups modified on MWNTs surface are a key factor for the formation the composite of MWNTs-MIPs. Attenuated total reflection Fourier transform infrared spectroscopy, transmission electron microscopy, scanning electron microscopy, and thermogravimetric analysis were used to characterize the composite structure and determine the grafted MIPs quantities in the composite. The properties such as adsorption dynamics, special binding, and selective recognition capacity were evaluated. The results demonstrated that MWNTs-MIPs not only possessed a rapid dynamic adsorption but also exhibited a high selectivity toward DA, compared to epinephrine. The electrochemical...
214 citations
TL;DR: The covalently immobilized MAA brushes significantly reduce the adhesion of the two bacterial strains and promote osteoblast cells' adhesion, proliferation, and alkaline phosphatase activity and have potential applications combating biomaterial-centered infection and promoting osseointegration.
195 citations
TL;DR: It is demonstrated that the capsules undergo reversible swelling in response to changes in external pH, and degrade in the presence of a physiological concentration of a natural thiol-containing peptide, glutathione.
Abstract: We report the preparation of monodisperse, single-component degradable polymer capsules for potential applications in encapsulation, catalysis, and controlled drug delivery. The synthesized capsules, composed entirely of poly(methacrylic acid) (PMA), are obtained by the sequential deposition of thiolated poly(methacrylic acid) (PMASH) and poly(vinylpyrrolidone) (PVPON) onto silica particles, controlled oxidation of thiol groups into bridging disulfide linkages in the PMASH, removal of the silica particles, and finally, release of PVPON by altering the solution pH to disrupt hydrogen bonding between PMASH and PVPON. The PMA capsules are held together solely through biodegradable disulfide linkages. We demonstrate that the capsules undergo reversible swelling in response to changes in external pH, and degrade in the presence of a physiological concentration of a natural thiol-containing peptide, glutathione. These capsules are of interest for in vivo applications, where degradation of the capsules, through ...
193 citations
TL;DR: In this paper, three imidazolium-based ionic liquid (IL) monomers, namely, 3-(1-ethyl imidzolium)-3-yl)propylmethacrylamido bromide (IL-1), 2-(1methylimidazolate dithiobenzoate (CTA-1) or (4-cyanopropyl dithionoic acid)-4-dithioester 4dithionzoate, and methacrylic acid (MAA) were
Abstract: Three imidazolium-based ionic liquid (IL) monomers, namely, 3-(1-ethyl imidazolium-3-yl)propylmethacrylamido bromide (IL-1), 2-(1-methylimidazolium-3-yl)ethyl methacrylate bromide (IL-2), and 2-(1-ethylimidazolium-3-yl)ethyl methacrylate bromide (IL-3), and methacrylic acid (MAA) were polymerized by the reversible addition fragmentation chain transfer (RAFT) process in methanolic solutions at 70 °C, using either 2-cyanopropyl dithiobenzoate (CTA-1) or (4-cyanopentanoic acid)-4-dithiobenzoate (CTA-2) as chain transfer agents (CTAs). Under these conditions, polymers exhibited molar masses predetermined by the initial molar ratio of the monomers to the dithioester precursor, as evidenced by 1H NMR spectroscopy from chain ends analysis. These hydrophilic polymers were subsequently used as macro-CTAs in chain extension experiments in aqueous or in alcoholic solutions, affording IL-based double hydrophilic block copolymers (DHBCs) of the type PIL-1-b-PAm, PMAA-b-PIL-2 and PMAA-b-PIL-3, where PAm and PIL stand f...
189 citations
TL;DR: In this article, the lower critical solution temperature (LCST) of MEO2MA-stat-MAA decreased with the increasing molar fraction of MAA in the copolymer in deionized water but increased in buffer solution at pH 7.
Abstract: Dual responsive molecular brushes consisting of statistical copolymers of di(ethylene glycol) methyl ether methacrylate (MEO2MA) and either methacrylic acid (MAA) or N,N-dimethylaminoethyl methacrylate (DMAEMA) were synthesized by grafting from poly(2-(2-bromoisobutyroyloxy)ethyl methacrylate (PBIEM) macroinitiators using atom transfer radical polymerization (ATRP). Copolymer brushes with controlled composition and molecular weights ranging from Mn = 600 000 to 1 400 000 with polydispersity indexes (Mw/Mn) between 1.18 and 1.45 were obtained. The lower critical solution temperature (LCST) of MEO2MA-stat-MAA decreased with the increasing molar fraction of MAA in the copolymer in deionized water but increased in buffer solution at pH 7. At pH 9, the hydrophilicity of polymer increased with ionization of carboxylic acid to further raise the LCST. On the other hand, the LCST of MEO2MA-stat-DMAEMA copolymers increased with increasing DMAEMA content at pH 4, 7, and 9. A bottle-brush terpolymer prepared from all...
174 citations
TL;DR: Oxidation of DOPA groups, a process that is greatly accelerated at a pH of 10, decreased the adhesive performance of the hydrogels even further, and hydrophilic and highly swellable, but less adhesive gels were formed.
157 citations
TL;DR: The results demonstrate that the pH during synthesis has a significant impact on the composition and thus the properties of the microgel and its ability to be utilized as a stimuli responsive stabilizer for emulsions.
Abstract: Responsive polymer microgels can be employed for the preparation of stimuli-sensitive emulsions. The microgels used in this study are based on cross-linked copolymers including N-isopropylacrylamide and methacrylic acid. We conducted the synthesis under acidic and basic conditions to investigate the effect of changes of comonomer solubility on the microgel’s composition and ability to stabilize emulsions. The synthesis product was partially divided into two fractions by centrifugation. Raw product, collected supernatant, and purified microgel were characterized by means of light scattering, titration, as well as electrophoretic mobility. The ability of the three components to act as stabilizers was investigated by preparing the octanol/water emulsions and looking at their response to pH and temperature changes. The interfacial activity of the three components was characterized by means of the pendent drop technique. Furthermore, we investigated the response of the interface to dilatational stress using a ...
140 citations
TL;DR: Water-soluble monodisperse superparamagnetic Fe3O4 nanocrystals decorated with two distinct functional groups are prepared in a single-step procedure by injecting iron precursors into a refluxing aqueous solution of a polymer ligand, trithiol-terminated poly(methacrylic acid) (PMAA-PTTM), bearing both carboxylate and thiol functionalities.
Abstract: Water-soluble monodisperse superparamagnetic Fe3O4 nanocrystals decorated with two distinct functional groups are prepared in a single-step procedure by injecting iron precursors into a refluxing aqueous solution of a polymer ligand, trithiol-terminated poly(methacrylic acid) (PMAA-PTTM), bearing both carboxylate and thiol functionalities. The ratio of carboxylic acid groups in the polymer-protecting ligand to the iron precursors plays a key role in determining the particle size and particle size distribution. The surface functionalities of the ligands allow post-synthesis modification of the materials to produce water-soluble fluorescent magnetic nanocrystals.
TL;DR: In this paper, a commercially available thin film composite polyamide (PA) nanofiltration (NF) membrane was chemically modified to improve its rejection capacity for selected organic micro-pollutants categorized as endocrine disrupting chemicals (EDCs) and pharmaceutically active compounds (PhACs): bisphenol-A (BPA), ibuprofen, and salicylic acid).
TL;DR: In this work the preparation of chitosan nanoparticle was investigated using methacrylic acid in different conditions and studied by particle size analyzer, zeta-potential, Fourier transform infrared spectroscopy, nuclear magnetic resonance (NMR) and transmission electron microscopy (TEM).
TL;DR: In this paper, PNIPAM graft chains were successfully synthesized via a combination of atom transfer radical polymerization (ATRP) and click reactions, where PAzPMA, PMAA, PnIPAM, and PQDMA are poly(3-azidopropyl methacrylate) fully quaternized with methyl iodide, respectively.
Abstract: Two oppositely charged graft ionomers, P(MAA-co-AzPMA)-g-PNIPAM and P(QDMA-co-AzPMA)-g-PNIPAM, containing thermosensitive PNIPAM graft chains were successfully synthesized via a combination of atom transfer radical polymerization (ATRP) and “click” reactions, where PAzPMA, PMAA, PNIPAM, and PQDMA are poly(3-azidopropyl methacrylate), poly(methacrylic acid), poly(N-isopropylacrylamide), and poly(2-(dimethylamino)ethyl methacrylate) (PDMA) fully quaternized with methyl iodide, respectively. In aqueous solution, polyelectrolyte complexation between negatively charged backbone of P(MAA-co-AzPMA)-g-PNIPAM and positively charged backbone of P(QDMA-co-AzPMA)-g-PNIPAM leads to the formation of polyion complex (PIC) micelles consisting of polyion complex cores and thermoresponsive PNIPAM coronas. Upon addition of a difunctional cross-linker, propargy ether, PIC micelles can be facilely cross-linked via “click” reactions. The obtained covalently core-stabilized PIC micelles exhibit permanent stability against the a...
TL;DR: In this paper, the propagation rate coefficients of N-vinyl pyrrolidone (NVP) radical polymerization in aqueous solution have been measured via the pulsed-laser polymerization -size exclusion chromatography method (PLP−SEC) over an extended concentration range from 1.8 to 100 wt % NVP at temperatures between 2 and 60 °C.
Abstract: Propagation rate coefficients, kp, of N-vinyl pyrrolidone (NVP) radical polymerization in aqueous solution have been measured via the pulsed-laser polymerization - size exclusion chromatography method (PLP−SEC) over an extended concentration range from 1.8 to 100 wt % NVP at temperatures between 2 and 60 °C. The SEC analyses have been carried out by a modified procedure using dimethyl acetamide as the eluent. An about 20-fold increase of kp is observed in passing from NVP bulk polymerization to reaction in dilute aqueous solution. As with nonionized methacrylic acid (MAA), for which a similarly strong change in kp has recently been reported, the large solvent effect in NVP polymerization is assigned to intermolecular interactions resulting in a significant hindrance of internal rotational motion in the transition state structure for propagation. Some contribution from a minor change in activation energy may however not be ruled out. PLP−SEC studies carried out on aqueous NVP solutions to which either poly...
TL;DR: In this article, the epoxy groups of the poly(GMA-MMA) beads were converted into amino groups during magnetization reaction, and then were grafted with methacrylic acid (MAA) via graft copolymerization.
TL;DR: In this article, the authors present a comprehensive investigation of the conformational switch of poly(methacrylic acid) using techniques which report on various length scales: fluorescence energy transfer experiments provide unique information on the nanometer length scale while dynamic light scattering (DLS) offers an insight into longer range interactions involved in the transition.
Abstract: Poly(methacrylic acid) (PMAA) undergoes a conformational transition between pH 4 and 6 from a hypercoiled structure to a water-swollen state. There has been much speculation as to the exact nature and driving force of the transition. In this paper, we present a comprehensive investigation of the conformational switch of PMAA using techniques which report on various length scales: fluorescence energy transfer experiments provide unique information on the nanometer length scale while dynamic light scattering (DLS) offers an insight into longer range interactions involved in the transition. Fluorescence energy transfer measurements demonstrate that PMAA undergoes subtle molecular rearrangements between pH 2 and 5 as short-range hydrophobic interactions between methyl groups are broken down by increasing concentrations of mutually repulsive carboxylate anions. Although such rearrangements have been proposed to account for the pH behavior of PMAA, we reveal them experimentally using techniques sensitive to na...
TL;DR: It was concluded that acidic conditions favour the recognition abilities of both polymers and that they can be used for a quick and efficient isolation of the polyphenol fraction directly from raw OMWW.
TL;DR: The incorporation of RTIL increased porosity, and hence improved selectivity of the prepared hybrid monoliths, and to give new insights into the mechanism of the RTIL‐mediated NHSG strategy.
Abstract: A room temperature ionic liquid (RTIL)-mediated nonhydrolytic sol-gel (NHSG) protocol was explored for the fabrication of new molecularly imprinted silica-based hybrid monoliths for chiral separation of a basic template zolmitriptan by CEC. The RTIL-mediated NHSG protocol involved free-radical copolymerization and NHSG process. Three carboxylic acids (trifluoromethyl acrylic acid, cinnamic acid, and methacrylic acid (MAA)) were examined as both the functional monomers and the catalysts for the NHSG condensation of methacryloxypropyltrimethoxysilane (MPTMS) to form silica-based framework. RTIL was incorporated to reduce gel shrinkage and also to act as the pore template. The effects of carboxylic acids and RTIL on the performance of the silica-based hybrid molecularly imprinted polymer (MIP) monoliths were investigated in detail to realize excellent chiral recognition and to give new insights into the mechanism of the RTIL-mediated NHSG strategy. Excellent chiral separation of (R)/(S)-zolmitriptan was achieved when the molar ratio of MAA to MPTMS was 1:4 and 1:2 with RTIL involved. The synergism of the free-radical copolymerization of the C=C bond of carboxylic acids and MPTMS with the NHSG condensation of MPTMS catalyzed by the carboxylic acids was demonstrated. The incorporation of RTIL increased porosity, and hence improved selectivity of the prepared hybrid monoliths.
TL;DR: In this article, the active control of multiple micellization and dissociation transitions of thermo- and pH-sensitive water-soluble block copolymers, poly(ethylene oxide)-b-poly(methoxydi(methylene glycol) methacrylate-co-methacrylic acid) (PEO-b-P(DEGMMA)-co-MAA)), in aqueous solutions by combining temperature and pH triggers.
Abstract: We report in this article on the active control of multiple micellization and dissociation transitions of thermo- and pH-sensitive water-soluble block copolymers, poly(ethylene oxide)-b-poly(methoxydi(ethylene glycol) methacrylate-co-methacrylic acid) (PEO-b-P(DEGMMA-co-MAA)), in aqueous solutions by combining temperature and pH triggers. Two block copolymers and one random copolymer P(DEGMMA-co-MAA) were prepared by atom transfer radical polymerization of a mixture of methoxydi(ethylene glycol) methacrylate (DEGMMA) and tert-butyl methacrylate (t-BMA) with a molar ratio of 100: 13 from a PEO macroinitiator and a small molecule initiator, respectively, and subsequent removal of t-butyl group. PDEGMMA is a thermosensitive water-soluble polymer exhibiting a lower critical solution temperature in water at 25 °C. The cloud point of P(DEGMMA-co-MAA) in water can be readily tuned from 24 to 60 °C by changing the solution pH. The block copolymers dissolved molecularly in cold aqueous buffer solutions with a pH o...
TL;DR: In this article, a two-stage distillation precipitation polymerization was used to obtain hollow poly(N-isopropylacrylamide) microspheres with sub-sequent removal of poly(methacrylic acid) (PMAA) core.
TL;DR: In this article, the response of surface-grafted poly(methacrylic acid)-block-poly(N-isopropylacrylamide) (PMAA-b-PNIPAM) layers to changes in pH, temperature and ionic strength was investigated by using in-situ multi-angle ellipsometry to measure changes in solvated layer thickness.
Abstract: Surface-initiated photoiniferter-mediated photopolymerization (SI-PMP) in presence of tetraethylthiuram disulfide is used to directly synthesize surface-grafted poly(methacrylic acid)-block-poly(N-isopropylacrylamide) (PMAA-b-PNIPAM) layers. The response of these PMAA-b-PNIPAM bi-level brushes to changes in pH, temperature and ionic strength is investigated by using in-situ multi-angle ellipsometry to measure changes in solvated layer thickness. As expected for a block copolymer architecture, PMAA blocks swell as pH is increased, with the maximum change in the thickness occurring near pH = 5, and PNIPAM blocks exhibit lower critical solution temperature (LCST) behavior, marked by a broad transition between swollen and collapsed states. The response of the bi-level brushes to changes in added salt at constant pH is complex, as the swelling behaviors of both the weak polyelectrolyte, PMAA, and thermoresponsive PNIPAM are affected by changes in ionic strength. This work demonstrates not only the robustness of SI-PMP for making novel, bi-level stimuli-responsive brushes, but also the complex links between synthesis, structure, and response of these materials.
TL;DR: A protocol was developed to use the efficient density functional calculations with B3LYP functional instead of the demanding CBS-QB3 method to determine the gas-phase free energies with relative high accuracy, thus enabling the determination of pKa values for the short oligomers of methacrylic acid.
Abstract: The acidity constant pKa for polymeric organic acid is expected to be different from its corresponding monomer value due to the change of chemical environment upon polymerization. Thermodynamic cycles were used to determine the free-energy changes for the proton dissociation processes in aqueous solution and the corresponding pKa values for monomer methacrylic acid and several similar carboxylic acids. First-principles calculations and continuum solvation model were used to determine the gas-phase and solvation free energies, respectively. A protocol was developed to use the efficient density functional calculations with B3LYP functional instead of the demanding CBS-QB3 method to determine the gas-phase free energies with relative high accuracy, thus enabling the determination of pKa values for the short oligomers of methacrylic acid. The predicted pKa values for the dimer and trimer of methacrylic acid are higher by about 0.8 pKa units than the predicted monomer value.
TL;DR: The MIP was applied to the solid-phase extraction of triterpenoids from a plant extract prior HPLC analysis, and a selective extraction of 18-beta-glycyrrhetinic acid from hydrolyzed extract of liquorice roots was achieved with a good extraction yield.
TL;DR: The results from this work suggest that the elasticity of the gels would be slightly reduced in vivo as a consequence of the high ionic strength present.
Abstract: pH-responsive microgel dispersions contain cross-linked polymer particles that swell when the pH approaches the pKa of the ionic monomer incorporated within the particles. In recent work from our group, it was demonstrated that the mechanical properties of degenerated intervertebral discs (IVDs) could be restored to normal values by injection of pH-responsive microgel dispersions (Saunders, J. M.; Tong, T.; LeMaitre, C.; Freemont, A. J.; Saunders, B. R. Soft Matter 2007, 3, 486). These dispersions change from a fluid to a gel with increasing pH. The present work investigates the pH-dependent properties of dispersions of microgel particles containing MAA (methacrylic acid) and also the effects of added Ca2+. Two microgels are discussed: microgel A is poly(EA/MAA/AM) (EA and AM are ethyl acrylate and allyl methacrylate), and microgel B is poly(EA/MAA/BDDA) (butanediol diacrylate). The pH-dependent particle properties investigated include hydrodynamic diameters and electrophoretic mobilities. The critical c...
TL;DR: In this paper, a molecularly imprinted composite membrane for selective binding and permeation of lovastatin acid from aqueous solutions was developed by means of target analogue imprinting strategy.
TL;DR: This work increases the diversity and functionality of nanoclay hydrogels, which display certain mechanical advantages over conventionally crosslinked hydrogela, which were synthesized by copolymerization with cationic and anionic comonomers.
Abstract: pH-sensitive nanoclay composite hydrogels based on N-isopropylacrylamide (NIPA) were synthesized by copolymerization with cationic and anionic comonomers. Laponite nanoclay particles served as multifunctional crosslinkers, producing hydrogels with exceptionally high mechanical strengths, as measured by elongation at break. Cationic copolymer gels based on NIPA and dimethylaminoethylmethacrylate were prepared by aqueous free radical polymerization, adopting a procedure reported by Haraguchi (Adv Mater 2002, 14, 1120-1124). Without modification, this technique failed to produce anionic copolymer gels of NIPA and methacrylic acid due to flocculation of clay particles. Three methods were conceived to incorporate acidic MAA into nanoclay hydrogels. First, NIPA was copolymerized with acidic comonomer under dilute conditions, producing hydrogels with good pH-sensitivity but weak mechanical characteristics. Second, NIPA was copolymerized with methyl methacrylate, which was then hydrolyzed to generate acid sidegroups, yielding hydrogels that were much stronger but less pH sensitive. Third, NIPA was copolymerized with an acid comonomer following modification of the nanoclay surface with pyrophosphate ions. The resulting hydrogels exhibited both strong pH-sensitivities at 37 degrees C and excellent tensile properties. Optical transparency changed during polymerization, depending on hydrophobicity of the components. This work increases the diversity and functionality of nanoclay hydrogels, which display certain mechanical advantages over conventionally crosslinked hydrogels.
TL;DR: The swelling kinetics of polymer matrix and release dynamics of thiram (fungicide) from hydrogels for the evaluation of the diffusion mechanism and diffusion coefficients suggest that Non-Fickian diffusion mechanism has occurred in both cases.
TL;DR: It was proved that the obtained MIP with introduced method was much better than that prepared in methanol as porogen and could be used as an adsorber for extraction and determination of pyridoxine in real and synthetic samples.
TL;DR: In this paper, a facile reduction method was used to synthesize monodisperse water-soluble magnetic Co nanoparticles in the presence of alkyl thioether end-functionalized poly(methacrylic acid) (PMAA-DDT) ligands.
Abstract: We report a synthesis of monodisperse water-soluble magnetic Co nanoparticles using a facile reduction method in aqueous media in the presence of alkyl thioether end-functionalized poly(methacrylic acid) (PMAA-DDT) ligands. The size and shape of the nanoparticles are both tunable by varying synthesis conditions. The size of the spherical nanoparticles can be tuned between 2–7.5 nm by changing the concentration of the polymer. Our synthesis approach also provides a route for producing much larger spherical nanoparticles of 80 nm as well as anisotropic nanorods of 15 × 36 nm. The spherical nanoparticles are superparamagnetic at room temperature. The nanoparticles can be stable in water for up to eight weeks when 0.12 mM PMAA-DTT with molecular weight of 13500 g mol−1 is used as ligand.