Showing papers on "Acrylic acid published in 2015"
TL;DR: Free-standing poly(vinyl alcohol)/poly(acrylic acid) (PVA/PAA) membranes with polydopamine (PDA) coating were prepared based on the combination of electrospinning and self-polymerization of dopamine to exhibit efficient adsorption performance towards methyl blue.
209 citations
TL;DR: In this article, a pH-sensitive cross-linked AA/Gelatin hydrogel was synthesized by free radical polymerization, where Ammonium persulfate and ethylene glycol dimethacrylate (EGDMA) were used as initiator and as cross-linking agent, respectively.
Abstract: This present work was aimed at synthesizing pH-sensitive cross-linked AA/Gelatin hydrogels by free radical polymerization. Ammonium persulfate and ethylene glycol dimethacrylate (EGDMA) were used as initiator and as cross-linking agent, respectively. Different feed ratios of acrylic acid, gelatin, and EGDMA were used to investigate the effect of monomer, polymer, and degree of cross-linking on swelling and release pattern of the model drug. The swelling behavior of the hydrogel samples was studied in 0.05 M USP phosphate buffer solutions of various pH values pH 1.2, pH 5.5, pH 6.5, and pH 7.5. The prepared samples were evaluated for porosity and sol-gel fraction analysis. Pheniramine maleate used for allergy treatment was loaded as model drug in selected samples. The release study of the drug was investigated in 0.05 M USP phosphate buffer of varying pH values (1.2, 5.5, and 7.5) for 12 hrs. The release data was fitted to various kinetic models to study the release mechanism. Hydrogels were characterized by Fourier transformed infrared (FTIR) spectroscopy which confirmed formation of structure. Surface morphology of unloaded and loaded samples was studied by surface electron microscopy (SEM), which confirmed the distribution of model drug in the gel network.
139 citations
TL;DR: In this paper, kraft lignin (KL) was copolymerized with acrylic acid (AA) in an aqueous solution to produce a water-solvable Lignin-based copolymers, which were characterized by Fourier Transform Infrared (FTIR) spectrophotometry and Nuclear Magnetic Resonance (NMR).
95 citations
TL;DR: The results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82% and the UV free radical polymerization of EPOLA was carried out using two types of photoinitiators, and the radiation curing behavior was determined by following the conversion of the acrylate groups.
Abstract: Over the past few decades, there has been an increasing demand for bio-based polymers and resins in industrial applications, due to their potential lower cost and environmental impact compared with petroleum-based counterparts. The present research concerns the synthesis of epoxidized palm oil acrylate (EPOLA) from an epoxidized palm oil product (EPOP) as environmentally friendly material. EPOP was acrylated by acrylic acid via a ring opening reaction. The kinetics of the acrylation reaction were monitored throughout the reaction course and the acid value of the reaction mixture reached 10 mg KOH/g after 16 h, indicating the consumption of the acrylic acid. The obtained epoxy acrylate was investigated intensively by means of FTIR and NMR spectroscopy, and the results revealed that the ring opening reaction was completed successfully with an acrylation yield about 82%. The UV free radical polymerization of EPOLA was carried out using two types of photoinitiators. The radiation curing behavior was determined by following the conversion of the acrylate groups. The cross-linking density and the hardness of the cured EPOLA films were measured to evaluate the effect of the photoinitiator on the solid film characteristics, besides, the thermal and mechanical properties were also evaluated.
85 citations
TL;DR: A palladium-catalyzed hydrocarboxylation of alkynes with formic acid has been developed that provides acrylic acid and derivatives in good yields with high regioselectivity without the need to handle toxic CO gas.
Abstract: A palladium-catalyzed hydrocarboxylation of alkynes with formic acid has been developed. The method provides acrylic acid and derivatives in good yields with high regioselectivity without the need to handle toxic CO gas.
84 citations
TL;DR: In this paper, the Diels-Alder reaction of furan and acrylic acid was run at 298 K and was catalyzed by Lewis acidic (Hf-, Zr-, and Sn-Beta) zeolite catalysts, and achieving a high turnover frequency (∼2 h −1) and no side reactions were observed.
Abstract: Routes to benzoic acid starting from furan—obtained from hemicellulose in high yield—and methyl acrylate are reported. These routes involve Diels–Alder and dehydration reactions of furan and acrylic acid (or methyl acrylate) in a two-step reaction protocol that minimizes side reactions. The Diels–Alder reaction of furan and methyl acrylate (or acrylic acid) was run at 298 K and was catalyzed by Lewis acidic (Hf-, Zr-, and Sn-Beta) zeolite catalysts, and achieving a high turnover frequency (∼2 h–1) and no side reactions were observed. The oxanorbornene product was dehydrated at low temperatures (298 to 353 K) in mixtures of methanesulfonic acid and acetic anhydride in 96% yield. This is compared to an only 1.7% yield of methyl benzoate obtained for the dehydration of the oxanorbornene in neat methanesulfonic acid. The effect of oxanorbornene concentration and stereochemistry was found not to decrease the yield of aromatics, while dehydration of the carboxylic acid form of the oxanorbornene led to a decreas...
83 citations
TL;DR: In this paper, the thermally stable properties of water-soluble polyacrylamide (PAM) and partially hydrolyzed polyacRYlamide(HPAM) polymers under various solution conditions have been studied utilizing Density Functional Theory (DFT) computational modeling method.
83 citations
TL;DR: The waste linear low density polyethylene-g-poly (acrylic acid)-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb(II) adsorbent.
Abstract: The purpose of this work is to remove Pb(II) from the aqueous solution using a type of hydrogel composite. A hydrogel composite consisting of waste linear low density polyethylene, acrylic acid, starch, and organo-montmorillonite was prepared through emulsion polymerization method. Fourier transform infrared spectroscopy (FTIR), Solid carbon nuclear magnetic resonance spectroscopy (CNMR)), silicon(-29) nuclear magnetic resonance spectroscopy (Si NMR)), and X-ray diffraction spectroscope ((XRD) were applied to characterize the hydrogel composite. The hydrogel composite was then employed as an adsorbent for the removal of Pb(II) from the aqueous solution. The Pb(II)-loaded hydrogel composite was characterized using Fourier transform infrared spectroscopy (FTIR)), scanning electron microscopy (SEM)), and X-ray photoelectron spectroscopy ((XPS)). From XPS results, it was found that the carboxyl and hydroxyl groups of the hydrogel composite participated in the removal of Pb(II). Kinetic studies indicated that the adsorption of Pb(II) followed the pseudo-second-order equation. It was also found that the Langmuir model described the adsorption isotherm better than the Freundlich isotherm. The maximum removal capacity of the hydrogel composite for Pb(II) ions was 430mg/g. Thus, the waste linear low-density polyethylene-g-poly (acrylic acid)-co-starch/organo-montmorillonite hydrogel composite could be a promising Pb(II) adsorbent.
78 citations
TL;DR: In this work carbomer microgels were combined with agarose networks in a semi-interpenetrating polymer network structure, aiming at obtaining suitable delivery systems for the loading and release of molecules with poor bioavailability but high therapeutic interest, like resveratrol.
Abstract: Carbomers, cross-linked poly(acrylic acid) microgels, have been widely used in pharmaceutical formulations as swollen hydrogels. Agarose, whose thermoreversibility may be exploited for drug loading, forms a gel with a mechanism involving coil-helix transition at about 36 °C. In this work carbomer microgels were combined with agarose networks in a semi-interpenetrating polymer network structure, aiming at obtaining suitable delivery systems for the loading and release of molecules with poor bioavailability but high therapeutic interest, like resveratrol. The rheological properties of the formulations and their in vitro cytocompatibility were studied and optimized acting on the neutralizing agent (triethylamine (N,N-diethylethanamine), triethanolamine (tris(2-hydroxyethyl)amine) and sodium hydroxide) and amount of OH donors (1,2-propanediol and glycerol). As a preparation method, autoclaving was introduced to simultaneously obtain heating and sterilising. Among the different neutralizing agents, NaOH was chosen to avoid the use of amines, considering the final application. Without the addition of alcohols as typical OH donors to induce Carbomer gelification, gels with appropriate rheological properties and stability were produced. For this formulation, the release of resveratrol after 7 days was about 80 % of the loaded mass, suggesting it is an interesting approach to be exploited for the development of innovative resveratrol delivery systems.
75 citations
TL;DR: In this article, a novel covalently crosslinked attapulgite/poly(acrylic acid-co-acrylamide) (ATP/P(AA-Co-AM)) nanocomposite hydrogel was synthesized via a facile one-pot two-step approach, with the modified ATP C C C nanorods as the sole crosslinker.
74 citations
TL;DR: The present study represents the first report on an integrated integrated process for production of acrylic acid at high purity and -yield from glycerol by an integrated process involving microbial and chemical catalysis.
Abstract: 3-Hydroxypropionic acid (3HP) and acrylic acid (AA) are industrially
important platform- and secondary chemical, respectively. Their production from
renewable resources by environment-friendly processes is desirable. In the
present study, both chemicals were almost quantitatively produced from
biodiesel-derived glycerol by an integrated process involving microbial and
chemical catalysis. Glycerol was initially converted in a fed-batch mode of operation to
equimolar quantities of 3HP and 1,3-propanediol (1,3PDO) under anaerobic
conditions using resting cells of Lactobacillus
reuteri as a biocatalyst. The feeding rate of glycerol was
controlled at 62.5 mg/gCDW.h which is half the maximum
metabolic flux of glycerol to 3HP and 1,3PDO through the L. reuteri propanediol-utilization (pdu) pathway to prevent accumulation of the inhibitory
intermediate, 3-hydroxypronionaldehyde (3HPA). Subsequently, the cell-free
supernatant containing the mixture of 3HP and 1,3PDO was subjected to selective
oxidation under aerobic conditions using resting cells of Gluconobacter oxydans where 1,3PDO was
quantitatively converted to 3HP in a batch system. The optimum conditions for
the bioconversion were 10 g/L substrate and 5.2 g/L cell dry weight. Higher
substrate concentrations led to enzyme inhibition and incomplete conversion. The
resulting solution of 3HP was dehydrated to AA over titanium dioxide
(TiO2) at 230 °C with a yield of >95 %. The present study represents the first report on an integrated
process for production of acrylic acid at high purity and -yield from glycerol
through 3HP as intermediate without any purification step. The proposed process
could have potential for industrial production of 3HP and AA after further
optimization.
TL;DR: A glucose and pH-responsive release system based on polymeric network capped mesoporous silica nanoparticles (MSN) exhibited an obvious enhanced release capacity in mild acidic conditions (pH 6.0).
Abstract: In this paper, a glucose and pH-responsive release system based on polymeric network capped mesoporous silica nanoparticles (MSN) has been presented. The poly(acrylic acid) (PAA) brush on MSN was obtained through the surface-initiated atom transfer radical polymerization (SI-ATRP) of t-butyl acrylate and the subsequent hydrolysis of the ester bond. Then the PAA was glycosylated with glucosamine to obtain P(AA-AGA). To block the pore of silica, the P(AA-AGA) chains were cross-linked through the formation of boronate esters between 4,4-(ethylenedicarbamoyl)phenylboronic acid (EPBA) and the hydroxyl groups of P(AA-AGA). The boronate esters disassociated in the presence of glucose or in acidic conditions, which lead to opening of the mesoporous channels and the release of loaded guest molecules. The rate of release could be tuned by varying the pH or the concentration of glucose in the environment. The combination of two stimuli exhibited an obvious enhanced release capacity in mild acidic conditions (pH 6.0).
TL;DR: Several hydrogels were synthesized from sodium alginate and copolymer of acrylic acid and acrylamide, which were characterized by FTIR, XRD, DTA-TGA, swelling and diffusion characteristics as mentioned in this paper.
TL;DR: The PANI-PAA composite with an optimized concentration of 200 ppm showed a marked increase in inhibition efficiency, i.e., 91.68% as mentioned in this paper, which is attributed to an insulating interfacial layer formed by the adsorption of PANI, which obstructs the corrosion reaction at the interface.
Abstract: Water-soluble polyaniline–poly(acrylic acid) (PANI–PAA) composites with excellent processability and electroactivity were prepared by a one-step in situ polymerization. PAA as a matrix not only improves the solubility of PANI in water but also prevents the formation of macroscopic PANI clusters. The corrosion-inhibition performance of 316 stainless steel (316SS) was evaluated in 0.5 M HCl by electrochemical measurements in the presence of PANI–PAA composites. The results show that PANI–PAA acts as a mixed-type inhibitor, and its inhibition efficiency (IE(R)) increases with inhibitor concentration. The adsorption of the inhibitor on 316SS surface obeys a Langmuir adsorption isotherm. The PANI–PAA composite with an optimized concentration of 200 ppm shows marked increase in IE(R), i.e., 91.68%. The enhanced efficiency is attributed to an insulating interfacial layer formed by the adsorption of PANI–PAA, which obstructs the corrosion reaction at the interface.
TL;DR: In this article, carboxylic acid nanogels (CANs) were incorporated into a Pebax MH 1657 matrix for potential applications in CO 2 /CH 4 (or N 2 ) separation.
TL;DR: The first Fe-facilitated decarboxylative cross-coupling reaction between α-oxocarboxylic acids and acrylic acids in aqueous solution has been developed, providing an efficient and expeditious approach to an important class of α,β-unsaturated carbonyls frequently found in bioactive compounds.
Abstract: The first Fe-facilitated decarboxylative cross-coupling reaction between α-oxocarboxylic acids and acrylic acids in aqueous solution has been developed. This transformation is characterized by its wide substrate scope and good functional group compatibility utilizing inexpensive and easily accessible reagents, thus providing an efficient and expeditious approach to an important class of α,β-unsaturated carbonyls frequently found in bioactive compounds. The synthetic potential of the coupled products is also demonstrated in subsequent functionalization reactions. Preliminary mechanism studies suggest that a free radical pathway is involved in this process: the generation of an acyl radical from α-oxocarboxylic acid via the excision of carbon dioxide followed by the addition of an acyl radical to the α-position of the double bond in acrylic acid then delivers the α,β-unsaturated carbonyl adduct through the extrusion of another carbon dioxide.
TL;DR: In this article, an ecofriendly superabsorbent composite (SB@PDA/PAA) was synthesized by grafting poly(acrylic acid) onto the surface of dopamine-coated waste sea buckthorn branches.
Abstract: With the purpose of decreasing production costs and mitigating negative effects on the environment, an ecofriendly superabsorbent composite (SB@PDA/PAA) was synthesized by grafting poly(acrylic acid) onto the surface of dopamine-coated waste sea buckthorn branches. The structure of the obtained products was analyzed using Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). The effects of pH level, salt concentration, cation type, and reswelling time on water absorbency were examined further. The results showed that the swelling behaviors of the superabsorbent composite were highly sensitive to the concentration of salt solution, cation type, and reswelling time. The swelling kinetics of SB@PDA/PAA in distilled water could be fitted well with a pseudo-second-order kinetic model. Moreover, the SB@PDA/PAA superabsorbent composites exhibited excellent water-retention properties and achieved a high degradability of 33.5 wt % when they were soaked in a soil solution for 90 day...
TL;DR: In this article, a natural polysaccharide, Gum ghatti (Gg), was modified to prepare cross-linked hydrogels using the grafting method initiated by gamma-radiation.
TL;DR: The modi cation of local polymeric conformation of poly(acrylic) acid (PAA), induced by hydration and neutralization with triethanol amine (TEA), was investigated by IR and Raman spectroscopy as discussed by the authors.
Abstract: The modi cation of local polymeric conformation of poly(acrylic) acid (PAA), induced by hydration and neutralization with triethanol amine (TEA), was investigated by IR and Raman spectroscopy. The e ect of water is the perturbation of hydrogen bonds established between di erent polymeric chains and the modi cation of the local conformation of the polymer. The neutralization with TEA a ects the carboxylic groups and modi es the local conformation of the polymer. These modi cations are correlated with the shift and the modi cation of the characteristics of IR and Raman spectra.
TL;DR: In this paper, the catalytic behavior of bifunctional V2O5/MFI catalysts with acid and oxidizing properties was investigated for the gas-phase oxidehydration of glycerol.
Abstract: The catalytic behavior of bifunctional V2O5/MFI catalysts with acid and oxidizing properties was investigated for the gas-phase oxidehydration of glycerol. One of the main reaction products was acrylic acid, produced by dehydration of glycerol to acrolein at an acidic site and subsequent oxidation at a redox site. Comparison of wet impregnation with vanadyl sulfate (VOSO4) and ammonium metavanadate (NH4VO3) showed that VOSO4 impregnation provided the best performance for the conversion of glycerol and selectivity towards acrylic acid. The chemical and structural properties of the catalysts were studied by X-ray diffraction, nitrogen adsorption–desorption isotherms, Raman spectroscopy, temperature programmed ammonia desorption, and X-ray absorption spectroscopy in the XANES region for the K-edge absorption of vanadium. XPS measurements of the fresh and spent catalysts enabled elucidation of the dynamic redox cycles of vanadium oxide during oxidation of acrolein. The presence of vanadium in the zeolite improved the catalyst lifetime, because of the multifunctional ability of the vanadium oxide species to convert acrolein to acrylic acid and act as co-catalyst for the oxidation of coked glycerol products. Qualitative and quantitative analyses of the coke deposited in the spent catalysts were performed using 13C NMR and thermogravimetry, respectively.
TL;DR: In this article, reaction pathways to a variety of monomers for commodity polymers are presented, starting from glucose, and reaction pathways for a wide range of precursors are presented.
Abstract: The synthesis of commodity polymers from biomass presents interesting challenges and opportunities for new catalytic chemistries. Starting from glucose, reaction pathways to a variety of monomers for commodity polymers are presented. The first step for each pathway is the isomerization of glucose to fructose. This reaction can now be accomplished in aqueous media with hydrophobic, large pore molecular sieves that contain Lewis acid sites as catalysts. A typical catalyst is a pure-silica molecular sieve having the zeolite beta topology and containing a small amount of framework Sn^(4+) (Sn-Beta). Dehydration of fructose into 5-hydroxymethylfurfural (HMF) provides a convenient path that can lead to 2,5-furandicarboxylic acid (FDCA) for the synthesis of polyethylene furanoate (PEF) or purified terephthalic acid (PTA) (via Diels–Alder reactions) for the synthesis of polyethylene terephthalate (PET). Recent progress on the dehydration of lactic acid could open new routes to acrylic acid and acrylonitrile that are used to produce polyacrylic acid and polyacrylonitrile, respectively, provided more selective catalysts for the retro-aldol deconstruction of fructose are developed.
TL;DR: The versatility of thiol-reactive (meth)acrylate species is demonstrated by the examples of a thermoresponsive copolymer showing aThiol-sensitive lower critical solution temperature (LCST) and the selective sequential modification with thiols and amines of a doubly reactiveCopolymer containing activated pentafluorophenyl esters.
TL;DR: In this article, the authors developed a biodegradable flocculent and adsorbent based on the graft co-polymer of the Gum ghatti (Gg) with the copolymer mixture of acrylamide (AAM) and acrylic acid (AA).
TL;DR: In this article, the grafting copolymerization between the sulfonated cellulose and acrylic acid (AA) was performed using potassium persulfate and N,N′-methylenebisacrylamide as the initiator and crosslinking agent, respectively, to prepare corn straw-co-AMPS-Co-AA hydrogels.
Abstract: In this study, the corn straw after removing the lignin was grafted with 2-acrylamido-2-methylpropanesulfonic acid (AMPS) to prepare sulfonated cellulose. The grafting copolymerization between the sulfonated cellulose and acrylic acid (AA) was performed using potassium persulfate and N,N′-methylenebisacrylamide as the initiator and crosslinking agent, respectively, to prepare corn straw-co-AMPS-co-AA hydrogels. The structure and properties of the resulting hydrogels were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, and dynamic rheometry. The effects of initiator, crosslinker, monomer neutralization degree, and temperature on the swelling ratio of the hydrogels were studied. The water retention, salt resistance, and recyclability of the corn straw-co-AMPS-co-AA hydrogels were also investigated. The optimum water absorptivity of the corn straw hydrogels was obtained at a polymerization temperature of 50 °C with 1.2% crosslinker, 1:7 ratio of the pretreated corn straw and AA, 2% initiator, and 50% neutralized AA.
TL;DR: A pH-sensitive superabsorbent hydrogel composite, sodium alginate-g-poly(acrylic acid-co-acrylamide) in the presence of polyvinylpyrrolidone (PVP), was prepared using the semi-interpenetrating polymer network (semi-IPN) technique and microwave irradiation.
Abstract: A pH-sensitive superabsorbent hydrogel composite, sodium alginate-g-poly(acrylic acid-co-acrylamide) in the presence of polyvinylpyrrolidone (PVP), was prepared using the semi-interpenetrating polymer network (semi-IPN) technique and microwave irradiation. Potassium peroxodisulfate (KPS) was used as an initiator, N,N,N′,N′-tetramethylene diamine (TEMED) as a reaction accelerator, and N,N′-methylene bisacrylamide (MBA) as a crosslinker. The Taguchi method was employed to optimize the synthetic conditions for the hydrogel based on water absorbency. The Taguchi L9 (34) orthogonal array was selected for the experimental design. The mass concentrations of MBA (C
MBA), KPS (C
KPS), and sodium alginate (C
NaAlg) as well as the molar ratio of acrylamide to acrylic acid (R
AM/AA) were chosen as the four factors in the design. Based on an analysis of variance in the test results, the optimal conditions were found to be 0.18 g/L of MBA, 0.60 g/L of KPS, 7.73 g/L of NaAlg, and R
AM/AA = 1:1. The maximum water absorbency of the optimized hydrogel was found to be 1551 g/g. The relative thermal stability of the hydrogel in comparison with sodium alginate was proven using thermogravimetric analysis. The prepared hydrogel was characterized by FTIR and scanning electron microscopy (SEM). The influences of environmental parameters such as the pH and the ionic strength of the solution on the water absorbency were also investigated.
TL;DR: This study investigates the structural features of porcine gastric mucin in aqueous dispersions and its interactions with water-soluble polymers using isothermal titration calorimetry, turbidimetric titration, dynamic light scattering, and transmission electron microscopy.
Abstract: This study investigates the structural features of porcine gastric mucin (PGM) in aqueous dispersions and its interactions with water-soluble polymers (poly(acrylic acid) (PAA), poly(methacrylic acid) (PMAA), poly(ethylene oxide), and poly(ethylene glycol)) using isothermal titration calorimetry, turbidimetric titration, dynamic light scattering, and transmission electron microscopy. It is established that PAA (450 kDa) and PMAA (100 kDa) exhibit strong specific interactions with PGM causing further aggregation of its particles, while PAA (2 kDa), poly(ethylene oxide) (1 000 kDa), and poly(ethylene glycol) (10 kDa) do not show any detectable effects on mucin. Sonication of mucin dispersions prior to their mixing with PAA (450 kDa) and PMAA (100 kDa) leads to more pronounced intensity of interactions.
TL;DR: The attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectrum confirms the formation of conjugated C=C double bonds with surface dehydrofluorination in poly(vinylidene fluoride) (PVDF) membrane.
Abstract: Poly(vinylidene fluoride) (PVDF) was modified by chemical treatments in order to create active double bonds to obtain covalent grafting of poly(acrylic acid) (PAA) on membrane. The attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectrum confirms the formation of conjugated C═C double bonds with surface dehydrofluorination. The membrane morphology was studied by scanning electron microscopy (SEM). The surface composition was characterized by X-ray photoelectron spectroscopy (XPS). The thermal stability of the dehydrofluorinated membrane (Def-PVDF) and functionalized membranes were investigated by differential scanning calorimetry (DSC) analysis. The influence of covalently attached PAA on Def-PVDF membrane has been investigated to determine its effect on the transport of water and charged solute. Variations in the solution pH show an effect on both permeability and solute retention in a reversible fashion. Metal nanoparticles were also immobilized in the membrane for the degradation of ...
TL;DR: In this paper, a new route to synthesize acrylic acid from acetic acid and formalin by one-step aldol condensation reaction was proposed and developed by using V-P/SiO2 oxide bifunctional catalysts designed and prepared by ultrasonic impregnation method.
Abstract: A new route to synthesizing acrylic acid from acetic acid and formalin by one-step aldol condensation reaction was proposed and developed. V-P/SiO2 oxide bifunctional catalysts were designed and prepared by ultrasonic impregnation method. The catalysts were characterized by XRD, BET, TEM, TG/DTA, and XPS, as well as NH3- and CO2-TPD and pyridine-FTIR methods. Catalytic performance wag evaluated using a fixed-bed tubular microreactor operating with a CH3COOH/HCHO (HAc/FA) molar ratio of 10 under atmospheric pressure. Influences of the balance between acidic and alkaline sites, as well as ratio of V4+ and V5+, on catalyst activity were further studied. Reaction parameters were systemically optimized. Through a series of comparisons, V-P/SiO2 binary oxide catalyst with a bulk density ratio of 1:2 was selected.
TL;DR: In this article, a carbon-based solid acid catalyst was used for cornstarch hydrolysis, achieving a total reducing sugar (TRS) concentration of 19.91 millimol/g.
TL;DR: The encapsulation of hydrophobic Nile Red molecules above the lower critical solution temperature of PNIPAM suggests that this polymer may be useful for removing hydrophilic pollutants.
Abstract: Core-corona inversion of micelles of diblock copolymer poly(acrylic acid)-block-poly(N-isopropylacrylamide) (PAA-b-PNIPAM), has been successfully realized by switching either pH or temperature. The strong interaction of doxorubicin with the PAA block and the pH-sensitive drug release from the polymer make the system very useful as a controlled drug delivery system. The encapsulation of hydrophobic Nile Red molecules above the lower critical solution temperature of PNIPAM suggests that this polymer may be useful for removing hydrophobic pollutants.