Commercial Resin Research Articles

High-precision digital light processing (DLP) printing of microstructures for microfluidics applications based on a machine learning approach

ABSTRACT Digital light processing (DLP) is renowned for its precision, but the challenge lies in the identification of optimal print parameters to minimise print errors and enhance overall print accuracy. This study introduces a groundbreaking approach by integrating 'Random Forest' (RF) models with DLP printing to construct a predictive model for printing errors to achieve unparalleled precision. We conducted experiments using common commercial resins to print, resulting in a comprehensive dataset of 690 experimental datasets. Consequently, we validated this approach by fabricating Y-type microfluidic structures with a minimum feature size printing of 2 µm and herringbone mixer structures with feature sizes of 21.2 µm. We successfully controlled the average print error below 2.3 µm. The 'RF' model was also extended from the printing of microfluidics (2.5D) to complex spatial three-dimensional (3D) Triple-Periodic Minimal Surface (TPMS) structures. We have successfully achieved the printing of TPMS-Gyroid and TPMS-Diamond structures with a minimum feature size of 20 µm, while the printing errors were all kept within 1.5 µm. This study underscores the generalizability and immense potential of integrating machine learning techniques with high-precision DLP printing, offering valuable insights for future research in the realm of high-precision and expeditious 3D printing.

Assessment of Degree of Conversion and Volumetric Shrinkage of Novel Self-Adhesive Cement.

The degree of monomer conversion and polymerization shrinkage are two of the main reasons for potential adhesion failure between the tooth structure and the restoration substrate. To evaluate the degree of conversion and polymerization shrinkage of a newly developed self-adhesive resin cement, the degree of conversion (DC) was measured using FTIR under different activation modes, temperatures, and times. Volumetric shrinkage was tested using the AcuVol video imaging method. The experimental cement showed a higher DC than other cements under self-curing. The DC of the experimental cement was higher than that of other cements, except SpeedCem Plus under light curing. The experimental cement had a higher DC than other cements, except SpeedCem Plus in some conditions under dual curing. All self-adhesive cements had a higher DC at 37 °C than at 23 °C under self-curing, and there was no statistical difference between 23 °C and 37 °C under light curing. All self-adhesive cements showed a significantly higher DC at 10 min than at 5 min under self-curing. There was no statistical difference between 5 min and 10 min for most cements under dual curing. All self-adhesive cements statistically had the same volumetric shrinkage under light curing and self-curing. The newly developed self-adhesive resin cement exhibited a higher degree of conversion and similar volumetric shrinkage compared to these commercial self-adhesive resin cements.

Ultrafast and selective capture of 99TcO4-/ReO4- from wastewater by hyper-branched quaternary ammonium group-functionalized resin

99Tc primarily exists high mobility in the natural aqueous environment due to its extremely high solubility and non-complexing features, which can easily cause radioactive pollution. We herein report a general strategy for constructing a novel resin (SiPAN-PEI) with multiple positive charges nitrogen, exhibiting ultrafast adsorption kinetics (< 3 min), superior adsorption capacities (463.96 mg g−1), and excellent selectivity in the presence of excess competitive anions, which exceed those of most commercial resins. Moreover, based on impressive structure stability in extreme conditions, SiPAN-PEI can still maintain superior adsorption abilities after suffering irradiation, calcination, and immersion in strong acid. In addition, the separation performance kept excellently after five loading-washing-eluting cycles and the total adsorption ratio can still reach 97 %. Outstandingly, SiPAN-PEI can remove most of ReO4- from simulated nuclear wastewater through a sequential injection automatic separation system and can reduce the concentration of ReO4- to the maximum concentration standard set by the World Health Organization (WHO) in a short time. Leveraging density functional theory calculations and other characteristics clearly elucidated adsorption mechanism of anion-exchange between Cl- and TcO4-/ReO4-. In terms of superior adsorption property, SiPAN-PEI is demonstrated to be a pretty candidate for 99Tc elimination from wastewater.

A microwave blackbody target for cosmic microwave background spectral measurements in the 10–20 GHz range

The Tenerife Microwave Spectrometer (TMS) is a ground-based radio-spectrometer that will take absolute measurements of the sky between 10–20 GHz. To ensure the sensitivity and immunity to systematic errors of these measurements, TMS includes an internal calibration system optimised for the TMS band, and cooled down to 4 K. It consists of an Aluminium core, composed of a baseplate and a bed of pyramidal elements coated with an absorber material and a metallic shield. The absorber coating is made of a commercial resin ECCOSORB CR/MF 117. To achieve the high stability (± 1 mK/h), temperature homogeneity (thermal gradients ΔT ≤ 25 mK), and emissivity (e ≥ 0.999) requirements of the reference unit, careful consideration has been given to the RF and thermal properties of the materials, as well as their geometry. In summary, this paper presents a comprehensive account of the design, characterisation, and test results of the TMS reference system.

Surface quality evaluation through 3D profilometry of dental restoration performed in a clinical simulated environment

This study evaluated the surface quality of Class V composite resin restorations, comparing the surface roughness resulting from applying three techniques for finishing and polishing in a condition of clinical simulated environment by using artificial dental arcade. Beyond the aesthetic aspect, the importance of the surface quality of the restoration is associated with biofilm accumulation that occur on the teeth restored surface depending on the roughness level, leading to carious lesions and gingivitis. The minimum roughness considered ideal to avoid the accumulation of bacterial biofilm, is 0.2 μm, and 0.5 μm for tactile perception. Most of the evaluations of the surface quality of restorative materials are performed in flat specimens, and the results can significantly differ from the clinical scenario. The present work discloses how heterogeneous the surface quality may result when dealing with natural teeth. The finishing and polishing techniques selected in this work comprised diamond burs and rubber points, diamond burs and surface sealant, and abrasive discs, for restoring premolar natural teeth using a commercial composite resin. The surface quality of the restoration resulting from the three techniques was investigated through Ra, Rt, Rp, R, Rk, Rpk, Rvk and RSm roughness parameters, extracted from 3D topography maps. It was found that the use of abrasive discs (G3) promoted better surface quality, with mean Ra roughness near 0.4 μm, against 0.6 μm for the surface sealant group (G2) and 1.0 μm for the rubber points group (G1). It was evidenced that, together with Ra, analyses of roughness parameters regarding the proportion of peaks and valleys, in this case, Rp and Rpk, and roughness spacing, RSm, were significant to gain confidence and reveal reliable screening of the performance between the three techniques, with the best surface condition of the restored area resulting from the use of abrasive discs.

Representative longevity testing of direct air capture materials

Direct-air CO2 capture (DAC) is a rapidly expanding field of research driven by a growing need for net-negative technologies. One leading class of materials for DAC isamine-based adsorbents, however these may have limited lifetime due to oxidative degradation. Material longevity is a critical parameter; however, most studies test the stability of thesematerials under inert atmospheres, removing the oxidation pathway. Consequently, more realistic longevity testing is needed.This work presents a method using ambient air andpartial vacuum conditions to assess the stability of DAC materials realistically. A custom-built, automated system was developed whereby CO2 adsorption was conducted in ambient air and desorption under vacuum.In this study, the novel method presented here is compared to a TGA methodfor analysis of the commercial ion exchange resin Lewatit VP OC 1065. A novel crosslinked polyamine designated here as CA-1 is also examined using the system undervarious conditions.The method involves the measurement and re-measurement of adsorption capacity between adsorption/desorption cycles. The Lewatit resin was cycled 180 times with desorption at 80 °C and 100 mbar absolute. In this test, itlost 31.20 % of original capacity, contrasted with a 5.47 % loss from the inert TGA method. The CA-1 crosslinked polyamine was thencycled 500 times at three sets of desorption conditions: 80 °C and atmospheric pressure, 80 °C and 500 mbar absolute, and 75 °C and 200 mbar absolute. The sample at 200 mbar lost only 2.79 % original uptake, compared to 28.74 % in atmospheric pressure.

Electrochemical determination of carbendazim in juice samples using carbon composite electrode modified with ion‐exchange resin

AbstractThis work describes a carbon composite modified electrode (CCME) easily prepared using a simple mixture of a commercial cation exchange resin (Amberlite IR 120H) as modifier, graphite powder and paraffin, which was successfully used for spontaneous preconcentration and voltametric determination of carbendazim (CBZ) in juice samples. Parameters such as amount of resin used in the composition of the electrode, pH and preconcentration time as well as instrumental parameters of differential pulse voltammetry (DPV) were studied. Under optimized conditions, the proposed sensor shows to be able to preconcentrate CBZ at an open circuit potential (OCP) condition and presented the highest analytical response in comparison to the unmodified electrode. An analytical curve was obtained for the CBZ determination employing the proposed CCME and showed a linear dynamic range (LDR) between 80.0 nmol L−1 to 2.0 μmol L−1, with a LOD of 19 nmol L−1 and LOQ of 65 nmol L−1. The effect of concomitants on the voltametric response was evaluated by addition and recovery study and a good selectivity was found. The proposed sensor was successfully applied for the determination of CBZ in spiked mango juice samples without any pretreatment.

Static and Impact Properties of Flax-Reinforced Polymers Prepared with Conventional Epoxy and Sustainable Resins.

The study assessed the tensile, flexural, and impact properties of composite materials reinforced with flax fibers, employing three distinct resin types. The composite laminates were fabricated using three commercial resins: a conventional epoxy resin, an epoxy resin with a 31% weight concentration of bio-renewable content, and a recyclable methyl methacrylate infusion resin. This aims to assess if there exists a commercially available alternative to the traditional epoxy resin that can reduce the overall carbon footprint of composite materials. To investigate the influence of humidity on the mechanical behavior of the flax layers, a drying treatment was applied to the fibers before the infusion process. Micro-computed tomography analysis revealed that heat treatment resulted in a reduction of porosity, although it did not affect the mechanical response of the composite laminates. Moreover, laminates produced with non-recyclable and sustainable resins exhibited no significant change in tensile and flexural modulus. In contrast, those produced with recyclable resin demonstrated a slight reduction in the strengths of the composite laminates. Conversely, out-of-plane impact tests and repeated impact tests indicated that composites prepared with recyclable and bio-epoxy resin formulations present superior damage resistance to repeated impact compared to traditional epoxy resin.

Fabrication of Soft Transparent Patient-Specific Vascular Models with Stereolithographic 3D printing and Thiol-Based Photopolymerizable Coatings.

An ideal vascular phantom should be anatomically accurate, have mechanical properties as close as possible to the tissue, and be sufficiently transparent for ease of visualization. However, materials that enable the convergence of these characteristics have remained elusive. The fabrication of patient-specific vascular phantoms with high anatomical fidelity, optical transparency, and mechanical properties close to those of vascular tissue is reported. These final properties are achieved by 3D printing patient-specific vascular models with commercial elastomeric acrylic-based resins before coating them with thiol-based photopolymerizable resins. Ternary thiol-ene-acrylate chemistry is found optimal. A PETMP/allyl glycerol ether (AGE)/polyethylene glycol diacrylate (PEGDA) coating with a 30/70% AGE/PEGDA ratio applied on a flexible resin yielded elastic modulus, UTS, and elongation of 3.41MPa, 1.76 MPa, and 63.2%, respectively, in range with the human aortic wall. The PETMP/AGE/PEGDA coating doubled the optical transmission from 40% to 80%, approaching 88% of the benchmark silicone-based elastomer. Higher transparency correlates with a decrease in surface roughness from 2000 to 90nm after coating. Coated 3D-printed anatomical replicas are showcased for pre-procedural planning and medical training with good radio-opacity and echogenicity. Thiol-click chemistry coatings, as a surface treatment for elastomeric stereolithographic 3D-printed objects, address inherent limitations of photopolymer-based additive manufacturing.

New design to enhance phosphonate selective removal from water by MOF confined in hyper-cross-linked resin

Although polymeric anion exchange resins can remove phosphonates, they lack selectivity for target phosphonates and are susceptible to interference by anions and other substances. Here, we developed a novel strategy via confining MIL-101(Fe)-NH2 inside commercial resins IRA-900 for high-efficient and precise phosphonate removal, accompanying with the improvement of the stability and recovery of MIL-101(Fe)-NH2. The obtained nanocomposite MIL-101(Fe)-NH2@IRA-900 (MFNI) exhibited significantly enhanced phosphonate removal in the presence of competing anions (Cl−, SO42−, NO3− and CO32−) and natural organic matter (humic acid) at high concentrations (2–4 times of phosphonate concentration). Moreover, MFNI displayed the highest phosphonate adsorption capacity (12.9 mg P/g) and the fastest adsorption kinetics (120 min) than hydrated ferric oxides modified IRA-900 (HFOI) (6.7 mg P/g, 180 min), MIL-101(Fe)-NH2 (7.6 mg P/g, 240 min) and IRA-900 (5.6 mg P/g, 360 min). Such higher adsorption affinity and anti-interference ability came from the synergistic effect of the host IRA-900 (hydrogen-bond interaction and electrostatic attraction) and the embedded MIL-101(Fe)-NH2 (ligand exchange). The depleted MFNI could be regenerated with a binary NaOH-NaCl solution and reused without significant loss of capacity. Column adsorption runs by using MFNI indicated the fresh MFNI could achieve 100 % removal of PPOA in 10.5 h continuously feeding, which offered the possibility of achieving potential large-scale applications. In general, a new MOF-confined design approach was practiced to achieve selective elimination of phosphates and to improve the stability and recovery of MOF.

Thermodynamic and Kinetic Equilibrium for Adsorption of Cellulosic Xylose of Commercial Cation-Exchange Resins.

The development of low-cost purification technology is an indispensable need for industrial biorefinery. Xylose is easily obtained from hydrothermal pretreatment of lignocellulosic biomass. This current study emphasizes the chromatographic monosaccharide separation process using commercial cation-exchange resins (CER) including Amberlite 120 and Indion 225 to separate xylose from a mixture of hydrolysates. To understand the performance of the two CER, the studies of equilibrium, thermodynamics, and kinetics were evaluated. In this study, with different xylose concentrations, the adsorption equilibrium was found to follow the Freundlich isotherm model well (R2 > 0.90 for both CER). The results indicated that a pseudo-second-order model represented the xylose adsorption kinetics. In addition, the activation energy of xylose adsorption onto both CER, i.e., Amberlite 120 and Indion 225 was 34.9 and 87.1 kJ/mol, respectively. The present adsorption studies revealed the potential of these commercial CER to be employed as effective adsorbents for monosaccharide separation technology.

Effect of adding arginine at different concentrations to experimental orthodontic resins: an in vitro study.

The aim of this study was to assess the effect of adding arginine at different concentrations to commercial and experimental orthodontic resins on shear bond strength (SBS), as well as on the antimicrobial activity of arginine against S. mutans. Metal brackets were bonded onto the surface of 120 bovine incisors using Transbond, OrthoCem, and an experimental resin (ER), adding 0, 2.5, 5, and 7 wt.% of arginine. The SBS test was performed in deionized water at 37 ºC for 24 h, at 0.5 mm/min. SBS test results were subjected to two-way ANOVA and Tukey's test (α = 0.05). CFU/mL data (antimicrobial assessment) were assessed by Kruskal-Wallis and Dunn's tests (α = 0.05). No statistical difference between the resins was observed in untreated groups (p > 0.05). The addition of arginine at 2.5% (27.7 MPa) and 5% (29.0 MPa) increased the SBS of Transbond when compared (p < 0.05) to OrthoCem (18.5 and 15.6 MPa, respectively) and ER (16.3 and 18.1 MPa, respectively). Arginine at 7% improved the SBS of Transbond (24.1 MPa) and ER (21.0 MPa), which was statistically higher (p < 0.05) than OrthoCem (12.6 MPa). OrthoCem did not show a statistically significant difference at the three concentrations of arginine (p > 0.05). The addition of arginine to resins reduced the count of S. mutans (p < 0.05). As for ER, all concentrations of arginine significantly decreased CFU/mL (p < 0.05). Among commercial resins, only 7% of arginine significantly reduced CFU/mL. The addition of arginine did not interfere with the bond strength and demonstrated antibacterial activity against S. mutans.

Recovery of ammonium from stormwater by ion exchange: Purifying seepage water in laboratory and pilot scales

Ammonium removal from seepage water (representative stormwater) by ion exchange was investigated experimentally on laboratory and pilot scales. The results present the removal of ammonium from the worst-case scenario of stormwater, which is seepage water. Ammonium removal was efficiently accomplished with commercial resin CS16GC in proton and sodium forms. With the resin in H+ form, simultaneous removal of Na+, K+, Ca2+, and Mg2+ was achieved, whereas with the resin in Na+ form, other metals except Na+ were removed. Resin regeneration could be done efficiently with 2 mol/L HCl and 2 mol/L NaCl. Cyclic (7 cycles) ammonium removal runs were conducted with the CS16GC resin in Na+ form on both laboratory and pilot scale. Qualitatively, the results obtained from the cyclic runs done on laboratory and pilot scales were similar; however, some differences were observed because of slightly different feed compositions. In the pilot-scale run, 95–100% ammonium removal was obtained. The performance of the commercial resin was efficient compared with novel materials reported in the literature in an analysis method proposed by the authors. Ion exchange–based ammonium removal was shown to be an efficient method, and further investigation on the long-term stability of the process is warranted.

Niobium oxyhydroxide as a bioactive agent and reinforcement to a high-viscosity bulk-fill resin composite.

The present in vitro study incorporated niobium oxyhydroxide fillers into an experimental high-viscosity bulk-fill resin composite to improve its mechanical performance and provide it a bioactive potential. Scanning electron microscopy synthesized and characterized 0.5% niobium oxyhydroxide fillers, demonstrating a homogeneous morphology that represented a reinforcement for the feature. Fillers were weighed, gradually added to the experimental resin composite, and homogenized for one minute, forming three groups: BF (experimental high-viscosity bulk-fill resin composite; control), BF0.5 (experimental high-viscosity bulk-fill resin composite modified with 0.5% niobium oxyhydroxide fillers), and BFC (commercial bulk-fill resin composite Beautifil Bulk U, Shofu; positive control). In total, 10 specimens/groups (8 × 2 × 2 mm) underwent flexural strength (FS) tests in a universal testing machine (Instron) (500N). Resin composites were also assessed for Knoop hardness (KH), depth of cure (DoC), degree of conversion (DC), elastic modulus (E), and degree of color change (ΔE). The bioactive potential of the developed resin composite was evaluated after immersing the specimens into a simulated body fluid in vitro solution and assessing them using a Fourier-transformed infrared spectroscope with an attenuated total reflectance accessory. One-way ANOVA, followed by the Tukey's test (p<0.05), determined FS, DC, KH, and ΔE. For DoC, ANOVA was performed, which demonstrated no significant difference between groups (p<0.05). The high-viscosity bulk-fill resin composite with 0.5% niobium oxyhydroxide fillers showed promising outcomes as reinforcement agents and performed well for bioactive potential, although less predictable than the commercial resin composite with Giomer technology.

Unsaturated polyester resin synthesis for enhanced fiber-reinforced composite performance

This research aims to enhance traditional glass fiber composites by utilizing a mediumreactive unsaturated polyester resin (UPR) synthesized from ortho-phthalic anhydride. The UPR is formulated using unsaturated acids, glycols, and styrene monomers, with the reaction tailored to improve mechanical properties beyond those of standard commercial resins. The liquid resin's properties are evaluated for manufacturing viability, and its solidified form demonstrates superior performance compared to industrial benchmarks. The composite, produced via the hand layup technique, features a reduced resin-to-glass fiber ratio. Mechanical property tests confirm its robustness. Additionally, scanning electron microscopy (SEM) analysis reveals the microstructural characteristics to study the UPR performance.

Novel adhesive based on black soldier fly larvae flour for particleboard production

Protein-based adhesives are receiving considerable attention due to their potential to contribute to the development of environmentally friendly materials. Black soldier fly larvae (BSFL) can convert organic waste into high value-added products, such as proteins and fatty acids. The objective of this study is to formulate adhesives from BSFL flour and evaluate their suitability in the production of particleboards. To expose the functional groups of the proteins for reaction with the wood, denaturation strategies involving alkaline treatments were assessed. The effectiveness of these treatments was evaluated through Bradford solubility, SDS-PAGE, and FTIR analysis. Bradford analysis confirmed that the alkali treatment increased the protein solubility from 10.1 g/l for 0 M to 89.1 g/l for 1 M. FTIR analysis revealed changes in the relative intensity of bands attributable to the Amide I, II, and III regions, which are associated with the α-helix and β-sheet structures. The adhesive was applied in the manufacturing process via spraying, requiring an evaluation of the rheological properties of different formulations. Based on the rheological properties, the viscosities of 0.25 M and 1 M were measured at 0.082 Pa·s and 0.113 Pa·s, respectively, falling within the suggested range for particleboard manufacture. Subsequently, eucalyptus wood panels were manufactured using the BSFL-based adhesives, and their mechanical properties as well as water resistance were evaluated. Static bending and tensile strength perpendicular to the surface testing revealed that boards produced with BSFL adhesive exhibited mechanical values comparable to those of commercial resins. The performance of the manufactured materials was compared with the minimum standards outlined in international regulations.

Cross-linked amidoxime porous resin for selective gallium separation in Bayer solutions: Reaction mechanism and kinetic study

The commercial resin suffers from slow diffusion rates and long mass transfer times, limiting its practical application in gallium extraction in Bayer solution. A novel amidoxime grafted polyacrylonitrile-styrene–divinylbenzene (A-PSD) resin was prepared by suspension acrylonitrile-styrene–divinylbenzene resins and subsequent electrophilic addition of hydroxylamine hydrochloride with amidoxime. Adsorption sites and mechanism study proved that the Ga3+ reacted with the amidoxime groups (CNOH) on the A-PSD resins. The A-PSD resins for Ga3+ adsorption followed the Langmuir model and exhibited excellent adsorption performance in Bayer solution with a Ga3+ capacity of 14.67 mg/g at 25 °C. The kinetic adsorption experiment showed that the adsorption process was controlled by chemical reaction and followed the pseudo-second-order kinetic model. The penetration curves of the column experiments indicate the possibility of industrial application of A-PSD resins, which may lay the groundwork for a new alternative to Ga3+ adsorption resins.

Lignosulfonate and glycidyl ether modified urea formaldehyde wood adhesives for interior particleboard production

Purpose The purpose of this study is the development of sustainable and low-formaldehyde emission wood adhesive formulations. Design/methodology/approach Three-step urea formaldehyde (UF) resin has been in situ modified with calcium lignosulfonate (LS) and/or 1,4 butanediol diglycidyl ether (GE). The structural, chemical, thermal and morphological characterizations were carried out on resin samples. These resins have been applied for particleboard pressing, and UF, UF-LS and UF-GE were evaluated as P2 classes according to EN 312. Findings The results show that the improved LS- or diglycidyl ether-modified UF wood adhesives were successful in their adhesive capacity, and the formaldehyde content of the final product was obtained as low as 8 mg/100 g. This paper highlights that the presented adhesive formulations could be a potential eco-friendly and cost-effective alternative to formaldehyde-based wood adhesives for interior particleboard production. Research limitations/implications Combination of LS and GE resulted in weaker mechanical properties and fulfilled P1 class particleboards due to temperature and duration conditions. Therefore, in situ usage of LS or GE in UF resins is highly recommended for particleboard pressing. Formaldehyde content of particleboards was determined with the perforator method according to EN 12460-5 and all of the particleboards exhibited E1 class. LS was more efficient in decreasing formaldehyde content than GE. Practical implications This study provides the application of particleboards with low formaldehyde emission. Social implications The developed LS- and diglycidyl ether-modified UF resins made it possible to obtain boards with significantly low formaldehyde content compared with commercial resins. Originality/value The developed formaldehyde-based resin formulation made it possible to produce laboratory-scale board prototypes using LS or GE without sacrificing of press factors and panel quality.

Conveniently synthesis of porous crown-based resin with efficient 90Sr capture from highly acidic wastewater

Effective removal of radioactive 90Sr is crucial for both management of spent nuclear fuel and recovery of radioactive strontium resources, while it’s still a great challenge due to the presence of high acid levels and intense radiation. Herein, a novel porous resin (DtBuCH18C6@CG-71) were synthesized by introducing 4′,4″(5″)-di-tert-butyldicyclohexano-18-crown-6 onto CG-71 resin using vacuum impregnation. The DtBuCH18C6@CG-71 resin maintains superior adsorption abilities in extreme conditions, including high acid resistance (3–12 mol/L HNO3), substantial γ-irradiation (200 kGy 60Co), and elevated temperatures (50–100 ℃). Impressively, even when exposed to a high concentration of matrix ions (59 elemental ions), the Sr(II) adsorption ratio onto DtBuCH18C6@CG-71 resin remains near 100 % even in highly acidic condition, which performance outpaces most of commercial resins. Dynamic column tests using an automated separation system further confirmed the superior ability of DtBuCH18C6@CG-71 in term of extracting Sr(II) from wastewater. Given its impressive features, cost-effectiveness, and scalability, DtBuCH18C6@CG-71 resin holds promising potential for 90Sr disposal in nuclear wastewater.

Healable azopolymer coatings with photoinduced reversible solid-to-liquid transitions for trenchless rehabilitation of pipelines

The development of healable polymers is crucial for the maintenance of underground pipeline systems during trenchless rehabilitation. While photocurable resins are commercial materials for this purpose, we introduce an innovative option: azobenzene-containing polymers (azopolymers) with photoinduced reversible solid-to-liquid transitions. The newly developed azopolymer comprises a methacrylate backbone and side chains incorporating hexyl spacers, azobenzene moieties, and dodecyl tails. We compared the thermal stability, efficiency of photoinduced solid-to-liquid transition, and adhesive strength among azopolymers with varying molecular weights. Subsequently, we identified the most suitable azopolymer for PVC pipe lining. The robust trans azopolymer inner layer maintains a solid state at ambient temperatures. Upon pipe damage, UV irradiation triggers trans-to-cis isomerization, leading to the conversion of the solid trans azopolymer into a liquid cis state. This flowing cis azopolymer effectively repairs cracks and can be reverted to its trans isomer via visible light irradiation or thermal relaxation. Unlike commercial photocurable resins, the developed azopolymers offer the advantage of multiple repair cycles. This study highlights the potential of azopolymers with photoinduced reversible solid-to-liquid transitions as innovative healable materials in trenchless rehabilitation technology.