Anhydrous interfacial polymerization of sub-1 Å sieving polyamide membrane.

Highly permeable polyamide (PA) membrane capable of precise ionic sieving can be utilized for many energy-efficient chemical separations. To fulfill this target, it is crucial to innovate membrane-forming process to induce a narrow pore-size distribution. Herein, we report an anhydrous interfacial polymerization (AIP) at a solid-liquid interface where the amine layer sublimated is in direct contact with the alkane containing acyl chlorides. In such a heterophase interface, water-caused side reactions are eliminated, and the amines in compact arrangement enable an intensive and orderly IP reaction, leading to a unique PA layer with an ionic sieving accuracy of 0.5 Å. The AIP-PA membrane demonstrates excellent separation selectivities of monovalent and divalent cations such as Mg2+/Li+ (78.3) and anions such as Cl-/SO42- (29.2) together with a high water flux up to 13.6 L m-2 h-1 bar-1. Our AIP strategy may provide inspirations for engineering high-precision PA membranes available in various advanced separations.

Comparison of the efficacy and safety of removing bandage contact lenses on the fourth and seventh postoperative day after transepithelial photorefractive keratectomy.

Purpose: To compare the differences in the removal of bandage contact lenses (BCLs) at 4 and 7 days after transepithelial photorefractive keratectomy (TransPRK) in term of visual rehabilitation, eye discomfort, and postoperative complications. Methods: This retrospective cohort study included patients with myopia undergoing TransPRK; in Group 1, the BCLs were removed on the 4th postoperative day, while in Group 2, the BCLs were removed on the 7th postoperative day. All patients underwent a 6-month follow-up, including slit-lamp examination and visual acuity assessment. Subjective evaluations of pain and eye discomfort were recorded after the BCLs removal. Results: In total, 376 eyes of 191 patients in Group 1 and 346 eyes of 177 patients in Group 2 were enrolled. The two groups were matched for sex, age, preoperative corrected distance visual acuity, and tear film break-up time. Patients in Group 1 exhibited slightly lower levels of myopia, resulting in a shallower ablation depth and shorter ablation time than those in Group 2. No statistically significant differences in visual acuity recovery, haze severity, and incidence of infectious keratitis were observed within 6 months after surgery between the two groups. However, patients in Group 2 experienced significantly fewer discomfort symptoms (discharge, foreign body sensation, and blurred vision) after BCLs removal than patients in Group 1 and had fewer postoperative complications (recurrent corneal epithelial erosion). Conclusion: Delayed removal of the BCLs one week after TransPRK effectively alleviated early discomfort symptoms and reduced the risk of recurrent corneal epithelial erosion without increasing the likelihood of infectious keratitis.

Facile separation and regeneration of LiFePO4 from spent lithium-ion batteries via effective pyrolysis and flotation: An economical and eco-friendly approach.

The facile recycling of spent lithium-ion batteries (LIBs) has attracted much attention because of its great significance to the environmental protection and resource utilization. Hydrometallurgical process is the most common method for recycling spent LIBs, but it is difficult to economically recover spent LiFePO4 batteries, because of the complicated metal separation process and low added value of its products. Herein, a novel and facile approach has been developed to achieve the direct regeneration of LiFePO4 from spent LIBs. By employing a flotation process after effective pyrolysis, it is found that 91.57% of LiFePO4 can be recovered from spent LIBs. Different surface hydrophobicity of cathode and anode active materials could be achieved via the selective adsorption of causticized soluble starch on the surfaces of spent LiFePO4, which effectively enhances the separation performance in flotation process. The recovered LiFePO4 barely contains metal impurities, which can be directly regenerated as new LiFePO4 materials with the first discharge capacity of 161.37 mAh/g, and their capacity retention is as high as 97.53% after 100 cycles at 0.2C. A technology assessment and economic evaluation indicate the developed regeneration approach of LiFePO4 is environmentally and economically feasible, which avoids the complex element separation process and achieves the facile recycling of spent LiFePO4.

Adjunctive effects of orthokeratology and atropine 0.01% eye drops on slowing the progression of myopia.

CLINICAL RELEVANCE: All eye health care practitioners should know how to control myopia. BACKGROUND: Investigating the adjunctive effects of orthokeratology and 0.01% atropine eye drops on controlling the progression of myopia in Chinese children. METHODS: The prospective study included Chinese children aged 8 to 13 years having a spherical equivalent refractive error ranging from -2.00 to -5.00 D. Participants were categorised into two groups: combination group (orthokeratology and 0.01% atropine) or atropine group (0.01% atropine). The axial length and spherical equivalent refraction were measured at baseline and every three months post-treatment and compared over two years. RESULTS: The combinaion and atropine groups comprised 20 and 22 participants. Following two years of treatment, the average spherical equivalent refraction change was 0.88 ± 0.31 D and 1.14 ± 0.63 D in the combination group and atropine group, respectively (P = 0.026), with an average increment in axial length of 0.50 ± 0.17 mm and 0.61 ± 0.21 mm, respectively (P = 0.091). In the atropine group, increased axial length was positively correlated with baseline spherical equivalent refraction (P = 0.018) and negatively correlated with baseline age (P = 0.003). However, these correlations were not observed in the combination group. In the subgroup of subjects aged 8-10 years and another subgroup of subjects with shorter initial axial length (22.00 to 24.50 mm), the changes in axial length over two years were significantly smaller in the combination group than the atropine group. CONCLUSION: Orthokeratology and 0.01% atropine eye drops combination therapy were found to be more effective in reducing progression of myopia, as measured through spherical equivalent refraction changes, than atropine monotherapy in children over two years. Combinatorial therapy was more effective in controlling the elongation of axial length in children with younger baseline age or shorter baseline axial length.

How does the porphyrin-like vacancy affect the spectral properties of graphene quantum dots? A theoretical study.

By processing graphene quantum dot, an ideal semiconductor material with suitable band gap and higher electron mobility can be obtained. Thus, it has a broad prospect in the application of photoelectric response materials. Here, a graphene defect with porphyrin-like structure is selected to achieve the controlable light absorption. The double five-membered-ring parallel vacancy are based on self-healing properties of popular graphene defects. Aimed to separate exciton and hole more effectively and achieve higher photoelectric conversion efficiency, the occupied orbital and unoccupied orbital of the quantum dot with objected defect structure is taken as orderly dispersion to form an obvious charge separation state under the demonstration with first principles calculation. Most importantly, a real time real space charge separation is calculated by time-dependent ab-initio quantum dynamics based on numerical atomic basis sets. The result shows the specific graphene defects can form an efficient pure graphene photoelectric response medium like porphyrin skeleton, and the vacancy will induce to adjust and control the specific wavelength of the response light and charge separated state manipulably with odevity of number of peripheral carbon rings by the calculation of ultrafast process.

6.5% Efficiency of polymer solar cells based on poly(3-hexylthiophene) and indene-C(60) bisadduct by device optimization.

A power conversion efficiency of 6.48% was achieved for polymer solar cells based on poly(3-hexylthiophene) (P3HT) as donor and indene-C60 bisadduct (ICBA) as acceptor with an open-circuit voltage of 0.84 V, a short-circuit current of 10.61 mA/cm², and a fill factor of 72.7% under irradiation at AM1.5G, 100 mW/cm² at the optimized conditions of P3HT:ICBA = 1:1 (w/w), solvent annealing and pre-thermal annealing at 150 °C for 10 minutes.

Influence of sulfur oxidation on the absorption and electronic energy levels of poly(thienothiophene) derivatives.

Two poly(thienothiophene) derivatives containing thieno[3,2-b]thiophene-4,4-dioxide unit were synthesized by Pd-catalyzed Stille coupling method. They were poly(3,6-dihexyl-thieno[3,2-b]thiophene-4,4-dioxide vinylene) (P2) and poly(2,5-diyl-3,6-dihexyl-thieno[3,2-b]thiophene-4,4-dioxide)-co-(2,5-diyl-thiophene) (P4). Poly(3,6-dihexyl-thieno[3,2-b] thiophene vinylene) (P1) and poly(2,5-diyl-3,6-dihexyl-thieno[3,2-b] thiophene)-co-(2,5-diyl-thiophene) (P3) were synthesized for comparison with P2 and P4. After sulfur oxidation on the thienothiophene units, the absorption peaks of the polymer solutions were red-shifted from 540 nm of P1 to 625 nm of P2 and from 445 nm of P3 to 520 nm of P4. The absorption peaks of the polymer films were red-shifted more significantly from 542 nm of P1 to 630 nm of P2 and from 480 nm of P3 to 564 nm of P4. The lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy levels also decreased a lot after the sulfur oxidation. In comparison with P1, the LUMO and HOMO energy levels of P2 decreased by 0.59 and 0.35 eV, respectively. The levels were 0.87 and 0.39 eV lower in the LUMO and HOMO energy levels of P4 than in that of P3.