CS Process Research Articles

Distribution and Evaporation Characteristics of Rb and Cs in Complex Salt Brine Systems

The brine in salt lakes is rich in resources, including not only K, Mg, and B, but also valuable trace elements. During the enrichment and extraction of trace elements (Rb, Cs) from sodium sulfate subtype salt lake brines, the process is significantly influenced by the presence of other coexisting ions such as Li+, K+, and Mg2+.The physical and chemical properties of K+ are extremely similar to those of Rb+ and Cs+, and its impact on the extraction of Rb+ and Cs+ is particularly significant. When K+, Rb+, and Cs+ coexist, they can form solid solutions such as [(K, Rb)2SO4], [(K, Cs)2SO4], and [(Rb, Cs)2SO4]. The formation of these solid solutions can lead to severe losses of Rb and Cs during the evaporation process of the brine, resulting in low yield. In response to the aforementioned issues regarding the evaporation process of Rb and Cs, this paper uses the aqueous-salt system phase diagram as a guide and combines experimental research with simulation calculations to study the enrichment patterns of trace elements Rb and Cs in the Na+, K+//Cl-, CO32-, SO42--H2O aqueous-salt system, as well as the migration mechanism of Rb and Cs.

Highly-selective and well-effective removal of cesium ions by segregative titanium-ferrocyanide/chitosan melamine sponge composite

Selectively and efficiently removing Cs is of great urgency and challenge for the treatment of radioactive wastewater. In this work, titanium-ferrocyanide/chitosan melamine sponge composite (TFCM) was synthesized by cross-linking and titanium-doping strategy, and employed to remove Cs+ from water. The obtained TFCM exhibited excellent adsorption performance for Cs+, due to its porous and 3D skeleton structure. The TFCM demonstrated a broad range of pH (pH = 3–11) suitability and high removal ratio of Cs+. The adsorption behavior of TFCM on Cs+ conformed to the Langmuir adsorption process and pseudo-second-order kinetics model. Remarkably, TFCM displayed a high selectivity in Cs+ adsorption with the presence of other cationic (K+, Na+, Ca2+, Mg2+). TFCM could easily be separated from water because of loading on the melamine sponges. Besides, the TFCM could maintain more than 78.1 % removal ratio of Cs+ after five adsorption-desorption cycles. Furthermore, the concentration of Cs+ could decrease to 10 μg/L from 20 mg/L with a prominent removal ratio of 99.95 %. Characterization results revealed that the adsorption process of Cs+ by TFCM was dominated by ion-exchange. In summary, the TFCM is a high selectivity, efficiently and easily separable adsorbent with excellent application prospects for removing Cs from radioactive wastewater.

Conflict Dynamics of Post-Retrieval Extinction: A Comparative Analysis of Unconditional and Conditional Reminders Using Skin Conductance Responses and EEG.

The post-retrieval extinction paradigm, rooted in reconsolidation theory, holds promise for enhancing extinction learning and addressing anxiety and trauma-related disorders. This study investigates the impact of two reminder types, mild US-reminder (US-R) and CS-reminder (CS-R), along with a no-reminder extinction, on fear recovery prevention in a categorical fear conditioning paradigm. Scalp EEG recordings during reminder and extinction processes were conducted in a three-day design. Results show that the US-R group exhibits a distinctive extinction learning pattern, characterized by a slowed-down yet successful process and pronounced theta-alpha desynchronization (source-located in the prefrontal cortex) during CS processing, followed by enhanced synchronization (source-located in the anterior cingulate) after shock cancellation in extinction trials. These neural dynamics correlate with the subtle advantage of US-R in the Day 3 recovery test, presenting faster spontaneous recovery fading and generally lower fear reinstatement responses. Conversely, the CS reminder elicits CS-specific effects in later episodic tests. The unique neural features of the US-R group suggest a larger prediction error and subsequent effortful conflict learning processes, warranting further exploration.

Investigation on Microstructures, Hardness, Friction, and Wear of Cold Sprayed Ti6Al4V Coatings With Coating Thickness of 100-3000 µm

The effect of coating thickness (CT) on the microstructures, hardness, and wear of cold sprayed Ti-6Al-4V (CS-Ti64) coatings was systematically investigated since the prolonged high pressure CS deposition could change their microstructures and porosity levels. In addition, the CT was relatively important for their durability, performance, and service life. Therefore, the CS-Ti64 coatings with different CT of 100-3000 µm were prepared on commercially available Ti64 (CA-Ti64) substrates via high pressure CS processes. The CS-Ti64 coatings had low porosity levels wherewith severely deformed Ti64 particles with a crescent-shape could be seen in their cross-sectional microstructures. The hardness of the CS-Ti64 coatings increased with increased CT probably due to their lowered bulk porosity levels associated with longer high pressure CS deposition. As a result, the increased CT from 100 to 3000 µm resulted in a 9.8% decrease in the wear of the CS-Ti64 coatings. The wear of the CS-Ti64 coating with 3000 µm was 16.8% lower than that of the CA-Ti64 as all the CS-Ti64 coatings had lower wear than the CA-Ti64. It could be concluded that the prolonged high pressure CS deposition for the thick CS-Ti64 coatings had an influence on their porosity, hardness, and wear.

Preparation of highly hydrophilic cesium ion sieve and its performance in adsorbing Cs+

The unique properties of cesium compounds have garnered increasing attention, among which Cs2Ti6O13 shows great potential for applications. This paper synthesized Cs2Ti6O13(CTO-3) using a template-assisted solvothermal method with cesium carbonate as the cesium source and tetrabutyl titanate as the titanium source. Among them, F127 and hexadecylamine are used as template agents to modulate the surface morphology and hydrophilicity of the precursor. The cesium ion sieve H2Ti6O13 (HTO-3) synthesized after hydrochloric acid pickling has a large specific surface area and good hydrophilicity. This structure is conducive to the ion exchange between Cs+ and H+, resulting in a fast adsorption rate. It is completed within 2 h, and the adsorption capacity reaches 360 mg/g, which is significantly greater than that of the traditional high-temperature solid-phase method. The adsorption process of Cs+ on HTO-3 is more consistent with the pseudo-second-order kinetic equation model, and the adsorption process is chemical adsorption. HTO-3 exhibited good selectivity and cycle stability. At the fifth time of the adsorption-resolution cycle, the adsorption capacity was 87.1 % of the first time.

Cold spray processing of AA2024/Al2O3 coating on magnesium AZ31B alloy: Process parameters optimization, microstructure and adhesive strength performance of coating

The automotive and aerospace sectors are progressively employing the magnesium (Mg) alloy of the grade AZ31B because of its excellent castability, low density, and high ratio of strength to weight. Nevertheless, the limited ability of AZ31B alloy to withstand corrosion limits their use in several fields of technology. In order to solve this problem, the AZ31B alloy is coated utilizing an AA2024/Al2O3 metal matrix composite (MMC) coating that is applied by the cold spray coating (CS) method. The primary goal of this work is the parametric optimization of CS process for maximizing adhesive strength of MMC-coated Mg-alloy substrate. Response surface methodology (RSM) is implemented to find the optimum CS parameters, including feed rate of powder – FRP (g/min), standoff distance of gun – SDG (mm) and processing temperature – TEMP (°C). The regression-based parametric adhesion strength prediction (ASP) model was formulated using the RSM and statistically validated using analysis of variance (ANOVA). Employing 3D surface of responses, the influence of CS parameters on the adhesion strength of an MMC-coating was assessed. The findings revealed that when the MMC-coating was cold sprayed on the Mg-alloy using FRP of 22 g/min, SDG of 12 mm, and TEMP of 520 °C, the maximum adhesion strength of MMC-coating was 70 MPa (actual). Given less than 2% error at 95% confidence, the parametric ASP model correctly predicted the adhesion strength of the MMC-coating. The ANOVA findings showed that FRP (g/min) had significant effect on adhesive strength of MMC-coating followed by SDG (mm) and TEMP (°C). The MMC-coating applied using the RSM optimized CS parameters showed 70.73% superior adhesive strength owing to the lower porosity formation of 2 vol% which offers greater interfacial area. The ASP equation was formulated using the “best fitting line” approach and validated using ANOVA for predicting the adhesive strength (MPa) from the porosity formation (vol%) in the MMC-coating.

From Cs[C2N3] to Cs3[C6N9] – a thermal and structural investigation

Abstract Cesium dicyanamide Cs[C2N3] (≡ Cs[N(CN)2] or Cs[dca]) was obtained by a metathesis reaction in form of transparent colorless platelets. The results of single-crystal X-ray structure measurements and refinements (C2/c, Z = 8) with the monoclinic cell parameters a = 932.31(8), b = 1274.67(9), c = 824.94(7) pm, β = 110.803(3)° at −70 °C and a = 939.59(7), b = 1281.58(8), c = 827.57(6) pm, β = 110.610(3)° at 20 °C corroborate earlier results for this compound. The Raman and IR spectra of Cs[C2N3] are presented for the first time and the result compares well with those of NaCs2[C2N3]3. The heat-driven cyclotrimerization process of Cs[C2N3] was studied by thermal analyses (DSC) and temperature-dependent X-ray powder diffraction methods. At 370 °C, its trimerization product Cs3[C6N9] is formed, crystallizing in the orthorhombic space group Pbam with the cell parameters a = 3043.0(3), b = 1052.4(1) and c = 415.21(4) pm for Z = 4. The IR spectrum of this cesium tricyanomelaminate (Cs3[C6N9] or Cs3[TCM]) is presented, but a well-resolved Raman spectrum could not be acquired owing to fluorescence phenomena. An overview about the cyclotrimerization reactions of all pseudo-binary alkali-metal dicyanamides (A[C2N3]) to their corresponding tricyanomelaminates (A 3[C6N9]) with A = Li–Cs gives a basis for a discussion of the different thermal and structural characteristics.

Auditory aversive generalization learning prompts threat-specific changes in alpha-band activity.

Pairing a neutral stimulus with aversive outcomes prompts neurophysiological and autonomic changes in response to the conditioned stimulus (CS+), compared to cues that signal safety (CS-). One of these changes-selective amplitude reduction of parietal alpha-band oscillations-has been reliably linked to processing of visual CS+. It is, however, unclear to what extent auditory conditioned cues prompt similar changes, how these changes evolve as learning progresses, and how alpha reduction in the auditory domain generalizes to similar stimuli. To address these questions, 55 participants listened to three sine wave tones, with either the highest or lowest pitch (CS+) being associated with a noxious white noise burst. A threat-specific (CS+) reduction in occipital-parietal alpha-band power was observed similar to changes expected for visual stimuli. No evidence for aversive generalization to the tone most similar to the CS+ was observed in terms of alpha-band power changes, aversiveness ratings, or pupil dilation. By-trial analyses found that selective alpha-band changes continued to increase as aversive conditioning continued, beyond when participants reported awareness of the contingencies. The results support a theoretical model in which selective alpha power represents a cross-modal index of continuous aversive learning, accompanied by sustained sensory discrimination of conditioned threat from safety cues.

Solid-state cold spray welding: Evaluation and future direction

Welding is an important manufacturing process for joining complex parts. Despite their widespread use, there exist some drawbacks in the existing liquid-state (e.g., formation of undesirable heat-affected zones around weld area) and solid-state (e.g., high equipment and tooling costs, low production rates, and difficulty in joining intricate geometries) methods. These limitations continually spur the search for new joining processes to improve existing welding methods or develop new ones that circumvent these limitations. To provide a “greener” and low-cost alternative to the traditional welding processes that often produce “soft” heat affected zones (HAZs), we develop and evaluate the expansion of cold spray process—a solid-state high-velocity particle deposition process—to solid-state welding, a process we term cold spray welding (CSW). Using well-defined processing parameters, we cold spray welded (CSWed) AA 6061-T651 plate and compared the results with Tungsten inert gas (TIG) welded counterpart. Although TIG-welded samples exhibit higher tensile properties than CSWed samples (at least based on the CS processing parameters used in this study), our findings show that CSW indeed circumvents major drawbacks in traditional welding processes, including negligible microstructural alterations and the inhibition of deleterious phase transformation and suppression of deleterious HAZ. The examination of CSWed parts reveals low yield strength is connected to ubiquitous microvoids that are formed due to lack of metallurgical bonding; these microvoids act as microcrack initiation sites. We proceed to establish a failure mechanism in the CSWed part to provide direction for future optimization.

Efficient Spin-Orbit Charge-Transfer Intersystem Crossing and Slow Intramolecular Triplet-Triplet Energy Transfer in Bodipy-Perylenebisimide Compact Dyads and Triads.

Bodipy (BDP)-perylenebisimide (PBI) donor-acceptor dyads/triad were prepared to study the spin-orbit charge-transfer intersystem crossing (SOCT-ISC). For BDP-PBI-3, in which BDP was attached at the imide position of PBI, higher singlet oxygen quantum yield (ΦΔ =85 %) was observed than the bay-substituted derivative BDP-PBI-1 (ΦΔ =30 %). Femtosecond transient absorption spectra indicate slow Förster resonance energy transfer (FRET; 40.4 ps) and charge separation (CS; 1.55 ns) in BDP-PBI-3, while for BDP-PBI-1, CS takes 2.8 ps. For triad BDP-PBI-2, ultrafast FRET (149 fs) and CS (4.7 ps) process were observed, the subsequent charge recombination (CR) takes 5.8 ns and long-lived 3 PBI* (179.8 μs) state is populated. Nanosecond transient absorption spectra of BDP-PBI-3 show that the CR gives upper triplet excited state (3 BDP*) and subsequently, via a slow intramolecular triplet energy transfer (14.5 μs), the 3 PBI* state is finally populated, indicating that upper triplet state is involved in SOCT-ISC. Time-resolved electron paramagnetic resonance spectroscopy revealed that both radical pair ISC (RP ISC) and SOCT-ISC contribute to the ISC. A rare electron spin polarization of (e, e, e, e, e, e) was observed for the triplet state formed via the RP ISC mechanism, due to the S-T+1 /T0 states mixing.

Modeling and Optimization of the Adsorption of Cr (VI) in a Chitosan-Resole Aerogel Using Response Surface Methodology.

In this paper, a model for Cr (VI) removal and optimization was made using a novel aerogel material, chitosan-resole CS/R aerogel, where a freeze-drying and final thermal treatment was employed to fabricate the aerogel. This processing ensures a network structure and stability for the CS, despite the non-uniform ice growth promoted by this process. Morphological analysis indicated a successful aerogel elaboration process., FTIR spectroscopy corroborated the aerogel precursor's identity and ascertained chemical bonding after adsorption. Owing to the variability of formulations, the adsorption capacity was modeled and optimized using computational techniques. The response surface methodology (RSM), based on the Box-Behnken design using three levels, was used to calculate the best control parameters for the CS/R aerogel: the concentration at %vol (50-90%), the initial concentration of Cr (VI) (25-100 mg/L), and adsorption time (0.3-4 h). Analysis of variance (ANOVA) and 3D graphs reveal that the CS/R aerogel concentration and adsorption time are the main parameters that influence the initial concentration of CS/R aerogel metal-ion uptake. The developed model successfully describes the process with a correlation coefficient of R2 = 0.96 for the RSM. The model obtained was optimized to find the best material design proposal for Cr (VI) removal. Numerical optimization was used and showed superior Cr (VI) removal (94.4%) under conditions of a CS/R aerogel concentration of 87/13 %vol, with an initial concentration of Cr (VI) of 31 mg/L, and an adsorption time of 3.02 h. These results suggest that the proposed computational model can obtain an effective and viable model for CS material processing and for optimization of the uptake of this metal.

Comparison between Compressive Sensing and Non-Uniform Array for a MIMO GBSAR with Elevation Resolution: Simulations and Experimental Tests

Ground-based synthetic aperture radars (GBSAR) are popular instruments widely used for the monitoring of infrastructures. One of the main problems of ground-based interferometric radars is the elevation ambiguity. Multiple-input multiple-output (MIMO) arrays could solve this problem. This work proposes a study on possible MIMO configurations to achieve elevation resolution in ground-based radar measurements. Specifically, two array configurations are compared: a random sparse array suitable for the compressive sensing technique, and a non-uniform array. The two solutions are compared by means of simulations and experimental tests. An ad hoc system has been developed to jointly test the two configurations, and results obtained in a controlled and real urban scenario are shown. It is found that both systems are able to solve elevation ambiguity. The non-uniform array seems to achieve good performance in a general scenario, while the CS processing can outperform the other only after optimization, depending on the specific scenario and application.

Enhanced thermoelectric properties of Li and Mg co−substituted Bi2Sr2Co2O fabricated by combined conventional sintering and spark plasma sintering

• Highly dense Bi 2-2 x Li x Mg x Sr 2 Co 2 O y is prepared by the combined (CS + SPS) process. • Li/Mg co−doping increases electrical conductivity due to increased hole concentration. • Combined (CS + SPS) process is effective way for enhancing thermoelectric properties. Bi 2 Sr 2 Co 2 O y is a promising thermoelectric material for high–temperature applications and is normally fabricated by conventional solid–state sintering (CS). However, the CS processed Bi 2 Sr 2 Co 2 O y suffers from a low electrical conductivity due to a low bulk density, which is major hurdle for its widespread thermoelectric applications. In this work, we propose an effective way to solve this problem by conducting an additional spark plasma sintering (SPS) after the CS process. In addition, to further enhance the electrical transport properties of Bi 2 Sr 2 Co 2 O y , we increase the electrical conductivity through the co−substitution of Li and Mg for Bi in Bi 2 Sr 2 Co 2 O y . We believe that the combined process of CS and SPS as well as the co−substitution of Li and Mg are highly effective ways for improving the electrical transport properties of Bi 2 Sr 2 Co 2 O y .

Sludge retention time effects on recovery of soluble organic matters via polyhydroxyalkanoate storage in contact stabilization process under feast/famine regime

AbstractBACKGROUNDContact stabilization (CS) can be used to capture organic matters from wastewater. However, CS is less efficient in capturing soluble organic matters (SOMs). Recovery of SOMs is required to minimize carbon emission and to maximize organic recovery from wastewater.RESULTSSOMs were recovered by applying a feast/famine (F/F) regime in a CS process. Sludge retention time (SRT) was found to regulate the recovery efficiency of SOMs. At a SRT of 4 d, 44.7% of the removed soluble chemical oxygen demand (SCOD) in wastewater was recovered and stored into intracellular polyhydroxyalkanoates (PHA), leading to 12.8% decrease of CO2 emission in comparison with the conventional activated sludge process. The storage of PHA in waste sludge harvested at a SRT of 4 d significantly increased the methane yield (187.3 ± 5.9 mL (g VSS)−1). The dominant bacteria performing SOM recovery in CS belonged to the genera Tessaracoccus, norank_f__Caldilineaceacea, unclassified_f__Microbacteriaceae and Flavobacterium.CONCLUSIONSThe study demonstrated that applying F/F regime in a CS process can recover SOMs via PHA storage. The regulation of SRT can enhance SCOD recovery. The study provides a solution to enhance SOM recovery from wastewater instead of being oxidized into CO2. © 2022 Society of Chemical Industry (SCI).Highlights SCOD can be recovered via PHA by applying F/F regime in CS mode. The optimum SRT of 4 d resulted 44.7% SCOD recovery via PHA storage. PHA‐accumulating bacteria belonged to four genera. Anaerobic digestion of sludge resulted in a 17.6% higher CH4 yield. CO2 emission decreased 12.8% compared with conventional activated sludge process.

Highly selective adsorption and lattice process of cesium by cubic cyanide-based functional materials

Cesium (Cs) is a byproduct of nuclear bombs, nuclear weapons testing, and nuclear fission in nuclear reactors. Cs can enter the human body through food or air and cause lasting damage. Highly efficient and selective removal of 137Cs from low-level radioactive effluents (LLREs), which contain many radionuclides and dissolved heavy metal species, is imperative for minimizing LLRE volume, and facilitating their final disposal. Prussian blue analogs (PBAs) have received much attention as materials for the removal of radioactive Cs because of their affinity for adsorbing Cs+. In this study, an inexpensive and readily available cyanide-based functional material (PBACu) exhibiting high efficiency and excellent selectivity toward Cs capture was designed through a facile low-temperature co-precipitation process. Nano-PBACu, crystallizing in the cubic space group (Fm-3m (225)), has an average pore size of 6.53 nm; consequently, PBACu can offer abundant atomic occupation sites for capturing and incorporating Cs. Here, the pseudo-second-order kinetic model and Langmuir model fitted well with the adsorption of Cs + on PBACu, with a maximum capture capacity of 95.75 mg/g within 5 min, confirming that PBACu could rapidly capture Cs ions. PBACu strongly and selectively interacted with Cs even in a simulant containing large Na+, NH4+, Ca2+, and Mg2+ ion concentrations in an aqueous solution. The process of Cs + adsorption by cyanide-based functional crystals was confirmed to involve the entry of Cs+ into cyanide-based functional crystals to replace K+ and finally achieve the lattice incorporation of Cs. The current results broaden the lattice theory of radionuclide Cs removal and provide a promising alternative for the immobilization of Cs from radioactive wastewater.

Synthesis, characterization, and caesium adsorbent application of trigonal zinc hexacyanoferrate (II) nanoparticles

Trigonal zinc hexacyanoferrate (TZHF) nanoparticle adsorbents for effective caesium ion (Cs+) removal were prepared using the chemical coprecipitation method. The morphologies of zinc hexacyanoferrate (ZHF) were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), Transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HR-TEM), and energy-dispersive X-ray spectroscopy (EDS). These analyses confirmed that the trigonal structure of ZHF and surface area is 43.08 m2/g. Cs+ removal was dependent on pH, with the greatest adsorption occurring under near-neutral conditions, and the removal process decreased with increasing pH. The Langmuir model was determined to be suitable for describing the adsorption process of Cs+ by ZHF. The mechanism of Cs+ adsorption was examined by Total Reflection X-ray Fluorescence (TXRF) using the gallium internal standard. In addition, the main mechanism of Cs+ adsorption by the ion exchange process was proposed and discussed.

Behavior of nanobentonites in adsorption of cesium and strontium

Bentonites contain a large amount of montmorillonite and this nano-structured and nano-porous member of the smectite group determines the adsorption properties of bentonites. In this study, four types of Iranian commercial bentonite clays have been examined to determine the adsorption capacity of cesium and strontium. The physicochemical and mineralogical properties of the four types have been experimentally analyzed with the focus on the moisture content, pH, dry (granulometric) and wet screen analyses; swell, sediment and Methylene Blue (M.B.) indices; cation exchange capacity (C.E.C) measurements. The pH and C.E.C values of B3 were 9.48 and 71.9 mEq/100g, respectively. The high values of C.E.C; swell, sediment and M.B. indices along with the high amount of granulometric values (particles finer than 36 um) showed that the B3 had a high amount of montmorillonite. X-Ray Fluorescence (XRF) analysis showed that the major of competing cations such as Ca2+ and K+ existing in B2 affects the Sr adsorption. The experimental analysis also showed that B2 had almost high pH and C.E.C values as well. The results of the separation process of Cs and Sr indicate that the B3 and B2 have the highest adsorption capacity of 59.75 and 45.5 for Cs and Sr adsorption, respectively.

Highly efficient Cesium Titanium (IV) Bromide perovskite solar cell and its point defect investigation: A computational study

Lead-free, halide-based perovskites are drawing appreciable attention for solar cell applications due to the non-toxic nature and stable performance in ambient environment. In this study, we investigated different facets of a Cesium Titanium (IV) Bromide (Cs 2 TiBr 6 ) perovskite solar cell (PSC) with ZnO and MoO 3 as charge transport materials. Upon numerical optimization of perovskite layer thickness, its defect density , and the interface defect density, we propose a highly efficient, practically realizable PSC with a power conversion efficiency of 18.15%. Besides, we investigated different point defects in Cs 2 TiBr 6 and the effect of their electronic band positions on the PSC performance. It is found that for Cs 2 TiBr 6 based PSC applications, the material processing of Cs 2 TiBr 6 is a crucial aspect and the PSC may underperform for deep defect states (0.2 eV ~ 1.6 eV) with defect density over 10 15 cm −3 . In addition, we analyzed different back contact materials and found that carbon-based back contact can be a low-cost solution to gold for Cs 2 TiBr 6 PSCs. • A Cesium Titanium (IV) Bromide (Cs 2 TiBr 6 ) based perovskite solar cell with FTO/ZnO/Cs 2 TiBr 6 /MoO 3 /Au structure is proposed. • An optimum power conversion efficiency (PCE) of 18.15% is achieved. • Investigation on possible point defects in Cs 2 TiBr 6 and their electronic band position's effect on the PSC performance. • For deep defect state (0.2 eV ~ 1.6 eV) and defect density over 10 15 cm −3 , the PSC tends to underperform. • Carbon-based back contact can be a possible low cost replacement of gold for Cs 2 TiBr 6 PSCs.

Synthetic mechanism of octenyl succinic anhydride modified corn starch based on shells separation pretreatment

Herein, the synthetic mechanism of octenyl succinic anhydride (OSA) modified corn starch (OSCS) and granule shells (OSCs) based on shells separation pretreatment (SSP) was investigated. High intensity peaks around 1720 and 1570 cm−1 were observed for OSCs in Fourier transform infrared (FTIR) spectra after SSP. OSCs showed higher degree of substitution (DS) values (ranging from 0.128 to 0.170) than OSCS (0.121) determined by 1H NMR. The average molecular weight (Mw) of OSA modified CS decreased, due to the introduction of OS groups. X-ray diffraction (XRD) indicated that esterification mainly took place in the amorphous regions of starch granules. X-ray photoelectron spectroscopy (XPS) revealed that a new peak corresponding to 1s orbital electrons of Na was obtained due to the introduction of OSA molecules. Meanwhile, lower surface DS and higher fluorescence intensity were noticed for OSCs. Conclusively, SSP would significantly increase the reaction efficiency of OSA modification process of CS.

Synthesis of potassium metal ferrocyanide/Al-MCM-41 with fast and selective adsorption of cesium

In this work, low-cost and non-toxic diatomite was used as the silicon source and aluminum source to synthesize Al doped MCM-41 (Al-MCM-41), and Cs+ adsorbents has been prepared by immobilizing the potassium metal ferrocyanide (KMeFC, Me = Cu2+, Ni2+, Zn2+, Co2+, and Fe3+) on Al-MCM-41. The adsorbents have high surface area from 471.7 to 685.8 m2 g−1, and their Cs+ adsorption performance has been detailed investigated. The max Cs+ adsorption capacity is 1.1602 mmol g−1, 1.092 mmol g−1, 0.8174 mmol g−1, 0.6973 mmol g−1, and 0.4541 mmol g−1 for KZnFC/Al-MCM-41, KNiFC/Al-MCM-41, KCoFC/Al-MCM-41, KCuFC/Al-MCM-41, and KFeFC/Al-MCM-41, respectively. The KZnFC/Al-MCM-41 presents the highest adsorption capacity, and it can reach adsorption equilibrium with 10 min. The pH experiment results show the KZnFC/Al-MCM-41 can keep a higher adsorption capacity in pH range from 2 to 11. What more, the KZnFC/Al-MCM-41 present good adsorption selectivity against to K+, Na+, Ca2+, and Mg2+. The adsorption mechanism was also discussed, and the adsorption results show the adsorption process of Cs+ by KMeFC/Al-MCM-41 conforms to pseudo-second-order kinetics and Langmuir isotherm adsorption model, and the thermodynamic experiments confirmed the adsorption process of Cs+ by KMeFC/Al-MCM-41 are endothermic and spontaneous. The FT-IR, XRD, and XPS of KZnFC/Al-MCM-41 before and after adsorption of Cs+ inferred that the adsorption process of the adsorbents mainly completed by the exchange between Cs+ and K+. This work provide a novel strategy to synthesis of KZnFC/Al-MCM-41 in low-cost and green route, and the adsorbent as-synthesized in this work is an efficient candidate for removing or extracting Cs+ from radioactive wastewater and mineral resources.