Gelation Of Aqueous Solutions Research Articles

The Effect of pH on the Viscoelastic Response of Alginate-Montmorillonite Nanocomposite Hydrogels.

Ionically cross-linked alginate hydrogels are used in a wide range of applications, such as drug delivery, tissue engineering, and food packaging. A shortcoming of these gels is that they lose their strength and degrade at low pH values. To develop gels able to preserve their integrity in a wide range of pH values, Ca-alginate-montmorillonite nanocomposite gels are prepared, and their chemical structure, morphology, and mechanical response are analyzed. As the uniformity of nanocomposite gels is strongly affected by concentrations of MMT and CaCl2, it is revealed that homogeneous gels can be prepared with 4 wt.% MMT and 0.5 M CaCl2 at the highest. The viscoelastic behavior of nanocomposite gels in aqueous solutions with pH = 7 and pH = 2 is investigated by means of small-amplitude compressive oscillatory tests. It is shown that Ca-alginate-MMT nanocomposite gels preserve their integrity while being swollen at pH = 2. The experimental data are fitted by a model with only two material parameters, which shows that the elastic moduli increase linearly with a concentration of MMT at all pH values under investigation due to formation of physical bonds between alginate chains and MMT platelets. The presence of these bonds is confirmed by ATR-FTIR spectroscopy. The morphology of nanocomposite gels is studied by means of wide-angle X-ray diffraction, which reveals that intercalation of polymer chains between clay platelets increases the interlayer gallery spacing.

Optimization of the rice husk ash production process for the manufacture of magnesium silicate hydrate cements

Different types of amorphous, silica-rich materials can be employed as supplemental cementitious materials (SCM) in Portland cement compositions that are more common. SCMs react with Ca(OH)2 in the presence of Portland cement and a water solution to create calcium silicate hydrate (C–S–H). When produced under specific circumstances, rice husk ash (RHA) contains a high concentration of amorphous silicon dioxide and is utilized as SCM in Portland cement formulations. Similar to this, materials high in amorphous silica, like RHA, encourage the production of hydrated magnesium silicate gels (M-S-H) in reactive magnesium aqueous solutions. Studies examining RHA's capacity to generate M-S-H under various temperature settings, however, are scarce. For the creation of cellulose-reinforced cementitious composites, M-S-H cements, which have superior mechanical qualities and reduced alkalinity (pH 9–10) as compared to Portland cement, are a suitable option. Because of this, the current study assesses the hydration reaction of magnesium oxide with silica produced from RHA and processed by various heat treatments (500, 550, 600, and 650 °C) to generate M-S-H. There were tests for mechanical stability, electrical conductivity, calorimetry, XRD, TG, pH, and more. As benchmarks, compositions containing MgO and commercially active silica (SF) were employed. The findings demonstrate that, in comparison to previous thermal treatments, RHA generated at 500 °C (RHA500) enabled the creation of an increased M-S-H concentration. The axial compressive strength of this composition (MgO/RHA500) in the initial phases is comparable to that of the reference composition (MgO/SF). Since the paste consisting of MgO/RHA500 had the lowest pH values at 30 days of curing, even when compared to the pH of the reference composition MgO/SF (pH 10.04), the calcination of RHA at 500 °C is also the best treatment to lower the alkalinity of the created system. The MgO/RHA500 composition's decreased alkalinity will enable the RHA generated at lower temperatures to be applied in a new way. The RHA, which is already a by-product of the agro-industrial sector with some added value, serves as a predecessor for the creation of M-S-H cement, which will promote both technical and environmental benefits for non-conventional cementitious materials.

Thermoresponsive Poly(N,N'-dimethylacrylamide)-Based Diblock Copolymer Worm Gels via RAFT Solution Polymerization: Synthesis, Characterization, and Cell Biology Applications.

RAFT solution polymerization is used to polymerize 2-hydroxypropyl methacrylate (HPMA). The resulting PHPMA precursor is then chain-extended using N,N'-dimethylacrylamide (DMAC) to produce a series of thermoresponsive PHPMA-PDMAC diblock copolymers. Such amphiphilic copolymers can be directly dispersed in ice-cold water and self-assembled at 20 °C to form spheres, worms, or vesicles depending on their copolymer composition. Construction of a pseudo-phase diagram is required to identify the pure worm phase, which corresponds to a rather narrow range of PDMAC DPs. Such worms form soft, free-standing gels in aqueous solution at around ambient temperature. Rheology studies confirm the thermoresponsive nature of such worms, which undergo a reversible worm-to-sphere on cooling below ambient temperature. This morphological transition leads to in situ degelation, and variable temperature 1H NMR studies indicate a higher degree of (partial) hydration for the weakly hydrophobic PHPMA chains at lower temperatures. The trithiocarbonate end-group located at the end of each PDMAC chain can be removed by treatment with excess hydrazine. The resulting terminal secondary thiol group can form disulfide bonds via coupling, which produces PHPMA-PDMAC-PHPMA triblock copolymer chains. Alternatively, this reactive thiol group can be used for conjugation reactions. A PHPMA141-PDMAC36 worm gel was used to store human mesenchymal stem cells (MSCs) for up to three weeks at 37 °C. MSCs retrieved from this gel subsequently underwent proliferation and maintained their ability to differentiate into osteoblastic cells.

Swelling of Thermo-Responsive Gels in Aqueous Solutions of Salts: A Predictive Model.

The equilibrium degree of swelling of thermo-responsive (TR) gels is strongly affected by the presence of ions in an aqueous solution. This phenomenon plays an important role in (i) the synthesis of multi-stimuli-responsive gels for soft robotics, where extraordinary strength and toughness are reached by soaking of a gel in solutions of multivalent ions, and (ii) the preparation of hybrid gels with interpenetrating networks formed by covalently cross-linked synthetic chains and ionically cross-linked biopolymer chains. A model is developed for equilibrium swelling of a TR gel in aqueous solutions of salts at various temperatures T below and above the critical temperature at which collapse of the gel occurs. An advantage of the model is that it involves a a small (compared with conventional relations) number of material constants and allows the critical temperature to be determined explicitly. Its ability (i) to describe equilibrium swelling diagrams on poly(N-isopropylacrylamide) gels in aqueous solutions of mono- and multivalent salts and (ii) to predict the influence of volume fraction of salt on the critical temperature is confirmed by comparison of observations with results of numerical simulation.

Photochemical transformation of hexachlorobenzene (HCB) in solid-water system: Kinetics, mechanism and toxicity evaluation

As one of the first batch of persistent organic pollutants (POPs) included in Stockholm Convention, hexachlorobenzene (HCB) has attracted great attention because of its wide occurrence and great environmental risks. Considering the easy adsorption of HCB on solids and the complexity of natural particles, we systematically investigated the photodegradation of HCB on the surface of silica gel (SG) in aqueous solution in this work to reveal its fate in natural waters. Under mercury lamp irradiation, more than 90% of HCB loaded on SG could be removed after 240 min. Moreover, the effects of solution pH and water constituents were examined, and results showed that the presence of NO2−, NO3−, Fe3+ and humic acid (HA) significantly inhibited the reaction due to the scavenging of ROS and/or competitive absorption of light. According to radical quenching experiments and electron paramagnetic resonance (EPR) spectra, hydroxyl radicals and singlet oxygen generated on the surface of SG could participate in the transformation of HCB, but •OH played a dominant role. Based on products identified by high performance liquid chromatography-mass spectrometry (HPLC-MS) and gas chromatography-mass spectrometry (GC-MS), two main pathways were proposed for the removal of HCB, including dechlorination and hydroxylation which represent direct and indirect photodegradation, respectively, and the occurrence of these two reactions was further supported by density functional theory (DFT) calculations. From the quantitative analysis of penta-chlorobenzene, it was estimated that dechlorination and hydroxylation contributed to approximately 44.4% and 55.6% of initial HCB degradation, respectively. Furthermore, toxicity predictions by the ecological structure–activity relationship model (ECOSAR) suggested that the toxicity of HCB was decreased in the photodegradation process. This study would provide important information for understanding the photochemical transformation mechanism of HCB at the solid/water interface.

A Predictive Model for Equilibrium Swelling of Thermoresponsive Gels in Aqueous Solutions of Surfactants

A Predictive Model for Equilibrium Swelling of Thermoresponsive Gels in Aqueous Solutions of Surfactants

Fine-Tuning of Molecular Structures to Generate Carbohydrate Based Super Gelators and Their Applications for Drug Delivery and Dye Absorption.

Carbohydrate-based low molecular weight gelators (LMWGs) exhibit many desirable properties making them useful in various fields including applications as drug delivery carriers. In order to further understand the structural connection to gelation properties, especially the influence of halide substitutions, we have designed and synthesized a series of para-chlorobenzylidene acetal protected D-glucosamine amide derivatives. Fifteen different amides were synthesized, and their self-assembling properties were assessed in multiple organic solvents, as well as mixtures of organic solvents with water. All derivatives were found to be gelators for at least one solvent and majority formed gels in multiple solvents at concentrations lower than 2 wt%. A few derivatives rendered remarkably stable gels in aqueous solutions at concentrations below 0.1 wt%. The benzamide 13 formed gels in water and in EtOH/H2O (v/v 1:2) at 0.36 mg/mL. The gels were characterized using optical microscopy and atomic force microscopy, and the self-assembly mechanism was probed using variable temperature 1H-NMR spectroscopy. Gel extrusion studies using H2O/DMSO gels successfully printed lines of gels on glass slides, which retained viscoelasticity based on rheology. Gels formed by the benzamide 13 were used for encapsulation and the controlled release of chloramphenicol and naproxen, as well as for dye removal for toluidine blue aqueous solutions.

Self-Supporting Hydrogels Based on Fmoc-Derivatized Cationic Hexapeptides for Potential Biomedical Applications.

Peptide-based hydrogels (PHGs) are biocompatible materials suitable for biological, biomedical, and biotechnological applications, such as drug delivery and diagnostic tools for imaging. Recently, a novel class of synthetic hydrogel-forming amphiphilic cationic peptides (referred to as series K), containing an aliphatic region and a Lys residue, was proposed as a scaffold for bioprinting applications. Here, we report the synthesis of six analogues of the series K, in which the acetyl group at the N-terminus is replaced by aromatic portions, such as the Fmoc protecting group or the Fmoc-FF hydrogelator. The tendency of all peptides to self-assemble and to gel in aqueous solution was investigated using a set of biophysical techniques. The structural characterization pointed out that only the Fmoc-derivatives of series K keep their capability to gel. Among them, Fmoc-K3 hydrogel, which is the more rigid one (G’ = 2526 Pa), acts as potential material for tissue engineering, fully supporting cell adhesion, survival, and duplication. These results describe a gelification process, allowed only by the correct balancing among aggregation forces within the peptide sequences (e.g., van der Waals, hydrogen bonding, and π–π stacking).

Equilibrium swelling of multi-stimuli-responsive copolymer gels

Copolymer gels prepared by polymerization of thermo-responsive and anionic monomers demonstrate strong sensitivity to several triggers such as temperature, pH and ionic strength of aqueous solutions. For biomedical applications of these materials (as on–off switches in controlled drug delivery and release), fine tuning of their volume phase transition temperature (VPTT) and a sharp decay in degree of swelling upon transition from the swollen to the collapsed state are needed. These requirements are fulfilled under swelling of copolymer gels and microgels in water under acidic conditions, but are violated when tests are conducted under alkaline conditions or in aqueous solutions of salts with physiological salinity.A model is developed for equilibrium swelling of multi-stimuli-responsive copolymer gels in aqueous solutions with arbitrary pH and molar fractions of a monovalent salt. Unlike conventional approaches, the model accounts for secondary interactions between chains (hydrogen bonding) to describe the kinetics of aggregation of hydrophobic segments above VPTT. Material constants are determined by fitting experimental swelling diagrams on poly(N-isopropylacrylamide–co–sodium acrylate) gels with various molar fractions of ionic monomers. The effects of temperature, pH and molar fraction of salt on the equilibrium degree of swelling below and above VPTT are studied numerically.

Rheological properties and stabilizing effects of high-temperature extracted flaxseed gum on oil/water emulsion systems

Flaxseed gums (FG) previously reported were mostly isolated from hulls and seeds under a relatively low temperature, which led to an incomplete structural and functional understanding of the entire gum. In addition, the influences of processing conditions on the functional properties of FG have rarely been studied. In this study, FG was extracted by water at high temperature (90 °C) followed by ethanol precipitation. The physicochemical characteristics of the high temperature extracted FG were investigated, including its rheological and emulsion stabilizing properties in aqueous solution. The influences of homogenization and heating-cooling treatments on the functional properties of FG were also examined. Results indicated that FG could form a gel in aqueous solution (>0.5 wt%) at room temperature (25 °C). Mechanical shearing forces derived from homogenization (50 MPa) highly decreased the elastic properties of FG by disrupting the intermolecular network. However, the disrupted network could not be recovered by reheating (85 °C) and cooling (25 °C) processes indicating it was non-reversible. It was also observed that FG of 0.4 wt% demonstrated the best stabilizing effect on the oil/water emulsion systems for the appropriate viscosity and weak-gel properties. The study aims to provide a full understanding of the rheological and emulsifying properties of high temperature extracted FG under different treating conditions with an intent to promote its application in the food and non-food industries.

Study of agarose aggregate formation through rheological and DLS analyses

Agarose is a natural polymer extracted from algae that has the property of forming physical gels in aqueous solutions when heat is removed from the system. This property holds considerable potential considering its applications in food and pharmaceutical industries, especially for DNA analysis. In this article, different concentrations of agarose in aqueous solutions were submitted to a progressive change in temperature, in order to obtain more or less organized structures of macromolecules. During this process, dynamic light scattering (DLS) and rheological measurements were performed. For scattering measurements, the Kohrausch–William–Watts (KWW) equation was adjusted to the data to obtain the average relaxation rate of the process. Mathematical adjustments were made for both techniques, aiming to study the helix–coil transition of polymeric chains during the temperature change, relating them by calculating the apparent activation energy of the process. Both approaches showed that apparent active energy tends to decrease for dilute solutions and at high temperatures. Given the results with DLS and rheology, we identify similar points of the aggregate formation through the shape of the activation energy curves. However, we also verified that the activation energy values suffer influence according to the nature of the measure.

Electrochromic inverse opal photonic gel containing charged hydrogel in aqueous media for full color reflective display

Herein, we demonstrate electrochromism of charged inverse opal photonic gel (IOPG) in aqueous solution for full color reflective display. Opal-templated polymerization of hydroxyethyl methacrylate with ionizable monomer and subsequent etching formed the IOPG exhibiting a structural color by Bragg diffraction of light. The IOPG contained acrylic acid (AA) (or vinyl imidazole (VI)) that can be ionized above the pKa (or below the pKb) of the gel. Application of 4V bias induced apparent color changes of the AA-IOPG from red to green due to decreased osmotic pressure within the IOPG near the ITO surface. It was revealed that the local pH change by water-splitting under voltage bias is the main driving force for IOPG deswelling. The blue shift of the colors during voltage ON was found to be faster than the red shift at voltage OFF due to the electrophoretic migration of protons. The VI-IOPG, which swells at low pH due to a positively charged hydrogel, showed a slight red shift of the reflective color by voltage ON and blue shift upon when voltage OFF. The reproducible color changes of AA-IOPG upon the repeated ON/OFF bias clearly showed that the IOPG can be a promising candidate for a reflective display.

Synthesis of pyrazolopyrimidines in mild conditions by gold nanoparticles supported on magnetic ionic gelation in aqueous solution

In this study, novel magnetic nanoparticle (FeNi3) based gold NPs with high surface area and easy accessibility of active sites were successfully developed by a facile approach. FeNi3 was functionalized with ionic gelation (IG) groups acting as robust anchors so that the gold NPs were well dispersed on the FeNi3 without aggregation. Spirulina coating was carried out via a wet impregnation technique based on IG using tripolyphosphate as a cross‐linking agent. Because of the amplification effect of IG, high loading capacities were achieved for the nanocatalysts. Furthermore, FeNi3/IG/Au showed superparamagnetic properties, contributing to the easy recovery of the nanocatalysts by magnetic separation. FeNi3/IG/Au was developed for the synthesis of pyrazolopyrimidines in mild conditions. The FeNi3/IG/Au magnetic NPs were thoroughly characterized using transmission electron microscopy, field emission scanning electron microscopy, vibrating sample magnetometry, Fourier‐transform infrared spectroscopy, and thermogravimetric analysis. The FeNi3/IG/Au nanocatalyst showed high robustness and stability in reaction for up to five cycles without significant loss of activity, probably due to the high loading of IG in the catalyst.

A Sacrificial PLA Block Mediated Route to Injectable and Degradable PNIPAAm-Based Hydrogels.

Thermoresponsive poly(N-isopropylacrylamide) (PNIPAAm)-based injectable hydrogels represent highly attractive materials in tissue engineering and drug/vaccine delivery but face the problem of long-term bioaccumulation due to non-degradability. In this context, we developed an amphiphilic poly(D,L-lactide)-b-poly(NIPAAm-co-polyethylene glycol methacrylate) (PLA-b-P(NIPAAm-co-PEGMA)) copolymer architecture, through a combination of ring-opening and nitroxide-mediated polymerizations, undergoing gelation in aqueous solution near 30 °C. Complete hydrogel mass loss was observed under physiological conditions after few days upon PLA hydrolysis. This was due to the inability of the resulting P(NIPAAm-co-PEGMA) segment, that contains sufficiently high PEG content, to gel. The copolymer was shown to be non-toxic on dendritic cells. These results thus provide a new way to engineer safe PNIPAAm-based injectable hydrogels with PNIPAAm-reduced content and a degradable feature.

Polymer Brushes and Gels in Competing Solvents: The Role of Different Interactions and Quantitative Predictions for Poly(N-isopropylacrylamide) in Alcohol–Water Mixtures

Cononsolvency occurs if a mixture of two good solvents causes the collapse or demixing of polymers into a polymer-rich phase in a certain range of compositions of these two solvents. The better solvent is usually called the cosolvent, and the other common solvent is called the solvent. An unsolved problem in the understanding of the cononsolvency transition of polymers is the role of various polymer–solvent and cosolvent–solvent interactions. In this work, using a mean-field model, we offer a comprehensive and quantitative theoretical study of the cononsolvency effect of neutral immobilized polymers, in particular, poly(N-isopropylacrylamide) (PNiPAAm) brushes and macrogels. Our model quantitatively describes and predicts the phase-transition behaviors of PNiPAAm brushes and gels in various aqueous alcohol solutions. We demonstrated that in addition to the dominant polymer–cosolvent preferential adsorption and monomer–cosolvent–monomer triple contact (cosolvent-assisted temporary cross-linking effect), a nonideal mixing between the polymer and solvent shifts the collapse transition to the lower-concentration region of the cosolvent, while an increase of the demixing tendency between the cosolvent and solvent reduces the width of the cononsolvency transition. Moreover, weakening of the cononsolvency transition in cosolvent-poor aqueous solutions at high hydrostatic pressure can be explained by the suppression of demixing tendencies between the cosolvent and water, and between polymer and water in the case of PNiPAAm.

Thermodynamic framework for switching the lower critical solution temperature of thermo-sensitive particle gels in aqueous solvent

Switching the lower critical solution temperatures (LCSTs) of thermo-sensitive particle gels including poly(N-isopropylacrylamide) (PNIPAM), poly(N-diethylacrylamide) (PNDEAM), and poly(N-vinylcaprolactam) (PNVCL) was investigated in various aqueous solvents. Three prepared particle gels represented a single LCST in a pure water solution near human body temperature. By adding a chaotropic co-solvent, such as dimethylformamide (DMF) or dimethyl sulfoxide (DMSO), to given gels in aqueous solution, the degree of influence on change of LCST was significantly different due to the difference in chemical structures. LCSTs of polymer solutions were affected by changing solvent conditions from pure water to mixed solvents. The LCST behaviors of linear PNIPAM, PNDEAM, and PNVCL in water/DMF or DMSO were determined by thermo-optical analysis (TOA), which supported the switchability of LCSTs in hydrogel systems. We used the photon correlation spectroscopy (PCS) technique to measure the switched LCSTs of hydrogel particles in mixed solvent systems. The switched LCSTs of the investigated systems exhibited a non-linear trend by varying co-solvent contents. A molecular thermodynamic framework, a combination of the modified double lattice with chain length dependence (MDL-CL) model and the Flory-Rehner (F-R) model, was utilized to describe and correlate the liquid-liquid equilibrium (LLE) and thermosensitive swelling behaviors between linear and cross-linked polymer solutions. With the addition of chaotropic co-solvents, a non-linear trend for phase behaviors of the three polymers was described after taking into account temperature and composition dependence on the association fraction (ηij) between the species. We assumed the donor-acceptor concept and competitive hydrogen bonding between polymer/water and water/co-solvent. The association fraction for the secondary lattice model was modified from an arbitrarily determined value to a physically meaningful value. Accordingly, the phase equilibrium of the amphiphilic polymers influenced by the structure-breaker characteristics of the co-solute was properly implemented in both experimental and modeling aspects.

The effect of saccharides on equilibrium swelling of thermo-responsive gels.

Mechanical and optical properties of thermo-responsive (TR) gels change drastically at their volume phase transition temperature. As the critical temperature is strongly affected by the presence of small amounts of additives in aqueous solutions, TR gels can be employed as sensors for detection and recognition of multiple analytes (from specific ions to hazardous biochemicals to pathogenic proteins) and actuators for biomedical applications. A simplified mean-field model is developed for equilibrium swelling of TR gels in aqueous solutions of additives. Its advantage is that the model involves a relatively small (compared with the conventional approaches) number of material constants and accounts for changes in the thermo-mechanical response at transition from the swollen to collapsed state. The ability of the model to describe experimental swelling diagrams and to predict the influence of additives on the equilibrium degree of swelling and the volume phase transition temperature of TR gels is confirmed by comparison of observations on poly(N-isopropylacrylamide) gel in aqueous solutions of saccharides (glucose, sucrose and galactose) with results of numerical analysis.

Collapse–Decollapse of Thermosensitive Polyelectrolyte Gels in Aqueous Media

The effect of temperature on water sorption by gels based on the copolymers of N-isopropylacrylamide with sodium p-styrene sulfonate containing 1, 3, and 5 mol % of charged monomer units is studied in aqueous media in the presence of salt (NaCl, KCl) or urea. It is shown that the incubation of gels in salt solutions leads to compression of the gels. With increasing temperature, the collapse of gels is observed in all studied media. The difference in the gel collapse temperature in water and salt solution increases with an increase in the fraction of charged units in the polymer gel network and in the salt concentration in the solution. With a return temperature decrease and gel decollapse, the mass of all gels in salt solutions (0.5–5.0 wt %) is completely restored. The incubation of gels in aqueous solutions of urea (0.5–5.0 wt %) has practically no effect on water sorption by gels before the collapse and the collapse temperature. However, the degree of swelling of polyelectrolyte gels during decollapse caused by a temperature decrease is much lower than the initial value, in contrast to the completely reversible swelling of the poly(N-isopropylacrylamide) gel under similar conditions.

PHYSICO-CHEMICAL POLYMER AND HYDROGEL ON THE BASIS OF 1-CHLORO-3- PIPERIDINE-2-PROPYLACRYLATE

The radical polymerization of a new monomer with a piper dine cycle in the presence of a nitrogen-containing initiator in the environment of organic solvents was investigated. The influence on the polymerization process of such factors as the nature of the solvent, temperature, monomer and initiator concentration is studied. The main kinetic and energy parameters of the homopolymerization reaction are determined. The found values of the reaction orders for the monomer and initiators are 1.01 and 0.53, respectively, and the process activation energy is 56.7 kJ / mol. A synthesized cross-linked high molecular compound based on 1-chloro-3-piperidino-2-propylacrylate. The physicochemical properties of the obtained compound were studied, the rate of swelling in water and other media, resistance to degradation, and mechanical strength were determined. The synthesis of a polymer gel based on the ester of 1-chloro-3-piperidino-2-propyl acrylate is given in the article. Optimal conditions for obtaining the gel were chosen. The physical and chemical properties of solutions of the obtained hydrogels, including the kinetics of swelling of gels in aqueous solutions, are studied.

Photodegradation of decabromodiphenyl ethane (DBDPE) adsorbed on silica gel in aqueous solution: Kinetics, products, and theoretical calculations

Decabromodiphenyl ethane (DBDPE) is a kind of brominated flame retardant and an alternative to decabromodiphenyl ether (BDE-209). Significant photodegradation of DBDPE was found on the surface of silica gel (SG) in aqueous solution under simulated solar irradiation. The removal of DBDPE was enhanced under high pH conditions. The DBDPE degradation rate decreased with the addition of humic acid and an increase in the amount of DBDPE. The favorable stability and reusability of SG were presented for the promotion of DBDPE degradation. According to electron paramagnetic resonance (EPR) analysis, quenching experiments and theoretical calculations, OH can be generated from SG under simulated solar irradiation and was the main radicals for the DBDPE decomposition. Low brominated and hydroxylated DBDPEs (OH-DBDPEs) were identified by liquid chromatography time-of-flight mass spectrometry (LC-TOF-MS) and gas chromatography-mass spectrometry (GC–MS), from which hydrodebromination and hydroxyl substitution were proposed as the major reaction pathways. The photochemical transformation of organic compounds is ubiquitous on a solid surface in the natural environment, and thus, low brominated DBDPEs and OH-DBDPEs can be generated from the DBDPE parent compound. This study can provide reference information for the photochemical transformation of DBDPE adsorbed on a solid surface in natural waters.