Proton-assisted growth of ultra-flat graphene films.

Graphene films grown by chemical vapour deposition have unusual physical and chemical properties that offer promise for applications such as flexible electronics and high-frequency transistors1-10. However, wrinkles invariably form during growth because of the strong coupling to the substrate, and these limit the large-scale homogeneity of the film1-4,11,12. Here we develop a proton-assisted method of chemical vapour deposition to grow ultra-flat graphene films that are wrinkle-free. Our method of proton penetration13-17 and recombination to form hydrogen can also reduce the wrinkles formed during traditional chemical vapour deposition of graphene. Some of the wrinkles disappear entirely, owing to the decoupling of van der Waals interactions and possibly an increase in distance from the growth surface. The electronic band structure of the as-grown graphene films shows a V-shaped Dirac cone and a linear dispersion relation within the atomic plane or across an atomic step, confirming the decoupling from the substrate. The ultra-flat nature of the graphene films ensures that their surfaces are easy to clean after a wet transfer process. A robust quantum Hall effect appears even at room temperature in a device with a linewidth of 100 micrometres. Graphene films grown by proton-assisted chemical vapour deposition should largely retain their intrinsic performance, and our method should be easily generalizable to other nanomaterials for strain and doping engineering.

Development of an online calculator for the prediction of seizure freedom following pediatric hemispherectomy using the Hemispherectomy Outcome Prediction Scale (HOPS).

OBJECTIVES: Although hemispheric surgeries are among the most effective procedures for drug-resistant epilepsy (DRE) in the pediatric population, there is a large variability in seizure outcomes at the group level. A recently developed HOPS score provides individualized estimation of likelihood of seizure freedom to complement clinical judgement. The objective of this study was to develop a freely accessible online calculator that accurately predicts the probability of seizure freedom for any patient at 1-, 2-, and 5-years post-hemispherectomy. METHODS: Retrospective data of all pediatric patients with DRE and seizure outcome data from the original Hemispherectomy Outcome Prediction Scale (HOPS) study were included. The primary outcome of interest was time-to-seizure recurrence. A multivariate Cox proportional-hazards regression model was developed to predict the likelihood of post-hemispheric surgery seizure freedom at three time points (1-, 2- and 5- years) based on a combination of variables identified by clinical judgment and inferential statistics predictive of the primary outcome. The final model from this study was encoded in a publicly accessible online calculator on the International Network for Epilepsy Surgery and Treatment (iNEST) website (https://hops-calculator.com/). RESULTS: The selected variables for inclusion in the final model included the five original HOPS variables (age at seizure onset, etiologic substrate, seizure semiology, prior non-hemispheric resective surgery, and contralateral fluorodeoxyglucose-positron emission tomography [FDG-PET] hypometabolism) and three additional variables (age at surgery, history of infantile spasms, and magnetic resonance imaging [MRI] lesion). Predictors of shorter time-to-seizure recurrence included younger age at seizure onset, prior resective surgery, generalized seizure semiology, FDG-PET hypometabolism contralateral to the side of surgery, contralateral MRI lesion, non-lesional MRI, non-stroke etiologies, and a history of infantile spasms. The area under the curve (AUC) of the final model was 73.0%. SIGNIFICANCE: Online calculators are useful, cost-free tools that can assist physicians in risk estimation and inform joint decision-making processes with patients and families, potentially leading to greater satisfaction. Although the HOPS data was validated in the original analysis, the authors encourage external validation of this new calculator.

Risk factors of recurrence after incisional hernia preperitoneal repair: a long-term retrospective single-center cohort study.

PURPOSE: To explore the risk factors for incisional hernia (IH) recurrence following open prepertioneal repair. METHODS: Patients diagnosed with primary IH who underwent open preperitoneal repair at our hospital were enrolled. Patients were assessed, and perioperative factors were collected. Recurrence surveys were performed at regular intervals throughout the long-term postoperative follow-up. The risk factors for IH recurrence were identified using univariate and multivariate analyses. RESULTS: This study included 145 patients. Significant differences were found between recurrence and non-recurrence patients regarding pulmonary ventilation function (PVT), age, body mass index (BMI), mesh materials, type of surgery (clean, clean-contaminated, or contaminated), surgical site infections (SSIs), maximum width of the hernia defect (MWHD), and site of incisional hernia (P < 0.01). The univariate survival analysis revealed that PVT abnormalities, age > 70 years, BMI > 27 kg/m2, porcine small intestine submucosal (PSIS) mesh, non-clean surgery, SSIs, MWHD > 10 cm, and location in the lateral zones were significant factors for IH recurrence after open preperitoneal repair. The multivariate survival analysis showed that PVT abnormalities, age > 70 years, BMI > 27 kg/m2, and PSIS mesh were independent risk factors for IH recurrence after open preperitoneal repair. CONCLUSIONS: We identified PVT abnormalities, age > 70 years, BMI > 27 kg/m2, and PSIS mesh as novel risk factors for IH recurrence after open preperitoneal repair.

Moiré enhanced charge density wave state in twisted 1T-TiTe2/1T-TiSe2 heterostructures.

Nanoscale periodic moiré patterns, for example those formed at the interface of a twisted bilayer of two-dimensional materials, provide opportunities for engineering the electronic properties of van der Waals heterostructures1-11. In this work, we synthesized the epitaxial heterostructure of 1T-TiTe2/1T-TiSe2 with various twist angles using molecular beam epitaxy and investigated the moiré pattern induced/enhanced charge density wave (CDW) states with scanning tunnelling microscopy. When the twist angle is near zero degrees, 2 × 2 CDW domains are formed in 1T-TiTe2, separated by 1 × 1 normal state domains, and trapped in the moiré pattern. The formation of the moiré-trapped CDW state is ascribed to the local strain variation due to atomic reconstruction. Furthermore, this CDW state persists at room temperature, suggesting its potential for future CDW-based applications. Such moiré-trapped CDW patterns were not observed at larger twist angles. Our study paves the way for constructing metallic twist van der Waals bilayers and tuning many-body effects via moiré engineering.

Observation of Electronic Strong Correlation in VTe_{2}-2sqrt[3]×2sqrt[3] Monolayer.

Strong electron correlation under two-dimensional limit is intensely studied in the transition metal dichalcogenides monolayers, mostly within their charge density wave (CDW) states that host a star of David period. Here, by using scanning tunneling microscopy and spectroscopy and density functional theory calculations with on-site Hubbard corrections, we study the VTe_{2} monolayer with a different 2sqrt[3]×2sqrt[3] CDW period. We find that the dimerization of neighboring Te-Te and V-V atoms occurs during the CDW transition, and that the strong correlation effect opens a Mott-like full gap at Fermi energy (E_{F}). We further demonstrate that such a Mott phenomenon is ascribed to the combination of the CDW transition and on-site Coulomb interactions. Our work provides a new platform for exploring Mott physics in 2D materials.

Iron Vacancy Tunable Superconductor-Insulator Transition in FeSe/SrTiO_{3} Monolayer.

The Fe_{4}Se_{5} with a sqrt[5]×sqrt[5] Fe vacancy order is suggested to be a Mott insulator and the parent state of bulk FeSe superconductor. The iron vacancy ordered state has been considered as a Mott insulator and the parent compound of bulk FeSe-based superconductors. However, for the superconducting FeSe/SrTiO_{3} monolayer (FeSe/STO) with an interface-enhanced high transition temperature (T_{c}), the electronic evolution from its Fe vacancy ordered parent phase to the superconducting state, has not been explored due to the challenge to realize an Fe vacancy order in the FeSe/STO monolayer, even though important to the understanding of superconductivity mechanism. In this study, we developed a new method to generate Fe vacancies within the FeSe/STO monolayer in a tunable fashion, with the assistance of atomic hydrogen. As a consequence, an insulating sqrt[5]×sqrt[5] Fe vacancy ordered monolayer is realized as the parent state. By using scanning tunneling microscopy and scanning tunneling spectroscopy, the spectral evolution from superconductivity to insulator is fully characterized. Surprisingly, a prominent spectral weight transfer occurs, thus implying a strong electron correlation effect. Moreover, the Fe vacancy induced insulating gap exhibits no Mott gap-like features. This work provides new insights in understanding the high-T_{c} superconductivity in FeSe/STO monolayer.

Acid Radical Tolerance of Silane Coatings on Calcium Silicate Hydrate Surfaces in Aggressive Environments: The Role of Nitrate/Sulfate Ratio.

Silane is known as an effective coating for enhancing the resistance of concrete to harmful acids and radicals that are usually produced by the metabolism of microorganisms. However, the mechanism of silane protection is still unclear due to its nanoscale attributes. Here, the protective behavior of silane on the calcium silicate hydrate (C-S-H) surface is examined under the attack environment of nitrate/sulfate ions using molecular dynamics simulations. The findings revealed that silane coating improved the resistance of C-S-H to nitrate/sulfate ions. This resistance is considered the origin of silane protection against harmful ion attacks. Further research on the details of molecular structures suggests that the interaction between the oxygen in the silane molecule and the calcium in C-S-H, which can prevent the coordination of sulfate and nitrate to calcium on the C-S-H surface, is the cause of the silane molecules' strong adsorption. These results are also proved in terms of free energy, which found that the adsorption free energy on the C-S-H surface followed the order silane > sulfate > nitrate. This research confirms the excellent protection performance of silane on the nanoscale. The revealed mechanism can be further used to help the development of high-performance composite coatings.

Clinical Application Value of left Ventricular Pressure-Strain Loop Examination of Myocardial Dysfunction in Patients with Hypertension at Various Risk Levels.

Objective: This study aims to determine the variations in myocardial work among patients with essential hypertension at varying risk levels by analyzing the left ventricular pressure-strain loop. Additionally, this research aims to investigate the potential diagnostic significance of myocardial work parameters in identifying myocardial dysfunction in patients with essential hypertension. Methods: We conducted a study with 79 patients who have essential hypertension and 30 healthy adults. The essential hypertension patients were categorized according to their risk level, with 10 patients in the low-risk group, 11 in the medium-risk group, 23 in the high-risk group, and 35 in the very high-risk group. We included 30 healthy adults in the study as a control group. Clinical data such as height, weight, and blood pressure were collected for all groups. Routine echocardiographic dynamic images were collected, and speck tracking echocardiography was performed to analyze global longitudinal strain and myocardial work parameters were detected by the left ventricular pressure-strain loop. Finally, the global work index, global constructive work, global wasted work, global work efficiency, and global longitudinal strain were calculated and compared among groups. The correlation between blood pressure and myocardial work parameters was analyzed. Results: Compared with the control group, inter-ventricular septum thickness was thickened in the medium-risk groups, high-risk groups,and very high-risk groups, P < .001). There was a negative linear correlation between global work efficiency and blood pressure (systolic and diastolic, and a positive linear correlation was observed between blood pressure and global work index, global constructive work, and global wasted work. Conclusion: Left ventricular pressure-strain loop can be used to evaluate changes in left ventricular myocardial work of essential hypertension patients in the early stage and with different risk stratifications.

Comparison of the real-world effectiveness of vertical versus lateral functional hemispherotomy techniques for pediatric drug-resistant epilepsy: A post hoc analysis of the HOPS study.

OBJECTIVE: This study was undertaken to determine whether the vertical parasagittal approach or the lateral peri-insular/peri-Sylvian approach to hemispheric surgery is the superior technique in achieving long-term seizure freedom. METHODS: We conducted a post hoc subgroup analysis of the HOPS (Hemispheric Surgery Outcome Prediction Scale) study, an international, multicenter, retrospective cohort study that identified predictors of seizure freedom through logistic regression modeling. Only patients undergoing vertical parasagittal, lateral peri-insular/peri-Sylvian, or lateral trans-Sylvian hemispherotomy were included in this post hoc analysis. Differences in seizure freedom rates were assessed using a time-to-event method and calculated using the Kaplan-Meier survival method. RESULTS: Data for 672 participants across 23 centers were collected on the specific hemispherotomy approach. Of these, 72 (10.7%) underwent vertical parasagittal hemispherotomy and 600 (89.3%) underwent lateral peri-insular/peri-Sylvian or trans-Sylvian hemispherotomy. Seizure freedom was obtained in 62.4% (95% confidence interval [CI] = 53.5%-70.2%) of the entire cohort at 10-year follow-up. Seizure freedom was 88.8% (95% CI = 78.9%-94.3%) at 1-year follow-up and persisted at 85.5% (95% CI = 74.7%-92.0%) across 5- and 10-year follow-up in the vertical subgroup. In contrast, seizure freedom decreased from 89.2% (95% CI = 86.3%-91.5%) at 1-year to 72.1% (95% CI = 66.9%-76.7%) at 5-year to 57.2% (95% CI = 46.6%-66.4%) at 10-year follow-up for the lateral subgroup. Log-rank test found that vertical hemispherotomy was associated with durable seizure-free progression compared to the lateral approach (p = .01). Patients undergoing the lateral hemispherotomy technique had a shorter time-to-seizure recurrence (hazard ratio = 2.56, 95% CI = 1.08-6.04, p = .03) and increased seizure recurrence odds (odds ratio = 3.67, 95% CI = 1.05-12.86, p = .04) compared to those undergoing the vertical hemispherotomy technique. SIGNIFICANCE: This pilot study demonstrated more durable seizure freedom of the vertical technique compared to lateral hemispherotomy techniques. Further studies, such as prospective expertise-based observational studies or a randomized clinical trial, are required to determine whether a vertical approach to hemispheric surgery provides superior long-term seizure outcomes.

Hemispherectomy Outcome Prediction Scale: Development and validation of a seizure freedom prediction tool.

OBJECTIVE: To develop and validate a model to predict seizure freedom in children undergoing cerebral hemispheric surgery for the treatment of drug-resistant epilepsy. METHODS: We analyzed 1267 hemispheric surgeries performed in pediatric participants across 32 centers and 12 countries to identify predictors of seizure freedom at 3 months after surgery. A multivariate logistic regression model was developed based on 70% of the dataset (training set) and validated on 30% of the dataset (validation set). Missing data were handled using multiple imputation techniques. RESULTS: Overall, 817 of 1237 (66%) hemispheric surgeries led to seizure freedom (median follow-up = 24 months), and 1050 of 1237 (85%) were seizure-free at 12 months after surgery. A simple regression model containing age at seizure onset, presence of generalized seizure semiology, presence of contralateral 18-fluoro-2-deoxyglucose-positron emission tomography hypometabolism, etiologic substrate, and previous nonhemispheric resective surgery is predictive of seizure freedom (area under the curve = .72). A Hemispheric Surgery Outcome Prediction Scale (HOPS) score was devised that can be used to predict seizure freedom. SIGNIFICANCE: Children most likely to benefit from hemispheric surgery can be selected and counseled through the implementation of a scale derived from a multiple regression model. Importantly, children who are unlikely to experience seizure control can be spared from the complications and deficits associated with this surgery. The HOPS score is likely to help physicians in clinical decision-making.

Lightweight Deep Neural Network Method for Water Body Extraction from High-Resolution Remote Sensing Images with Multisensors.

Rapid and accurate extraction of water bodies from high-spatial-resolution remote sensing images is of great value for water resource management, water quality monitoring and natural disaster emergency response. For traditional water body extraction methods, it is difficult to select image texture and features, the shadows of buildings and other ground objects are in the same spectrum as water bodies, the existing deep convolutional neural network is difficult to train, the consumption of computing resources is large, and the methods cannot meet real-time requirements. In this paper, a water body extraction method based on lightweight MobileNetV2 is proposed and applied to multisensor high-resolution remote sensing images, such as GF-2, WorldView-2 and UAV orthoimages. This method was validated in two typical complex geographical scenes: water bodies for farmland irrigation, which have a broken shape and long and narrow area and are surrounded by many buildings in towns and villages; and water bodies in mountainous areas, which have undulating topography, vegetation coverage and mountain shadows all over. The results were compared with those of the support vector machine, random forest and U-Net models and also verified by generalization tests and the influence of spatial resolution changes. First, the results show that the F1-score and Kappa coefficients of the MobileNetV2 model extracting water bodies from three different high-resolution images were 0.75 and 0.72 for GF-2, 0.86 and 0.85 for Worldview-2 and 0.98 and 0.98 for UAV, respectively, which are higher than those of traditional machine learning models and U-Net. Second, the training time, number of parameters and calculation amount of the MobileNetV2 model were much lower than those of the U-Net model, which greatly improves the water body extraction efficiency. Third, in other more complex surface areas, the MobileNetV2 model still maintained relatively high accuracy of water body extraction. Finally, we tested the effects of multisensor models and found that training with lower and higher spatial resolution images combined can be beneficial, but that using just lower resolution imagery is ineffective. This study provides a reference for the efficient automation of water body classification and extraction under complex geographical environment conditions and can be extended to water resource investigation, management and planning.

Tuning the Electronic Structure of an α-Antimonene Monolayer through Interface Engineering.

The interfacial charge transfer from the substrate may influence the electronic structure of the epitaxial van der Waals (vdW) monolayers and, thus, their further technological applications. For instance, the freestanding Sb monolayer in the puckered honeycomb phase (α-antimonene), the structural analogue of black phosphorene, was predicted to be a semiconductor, but the epitaxial one behaves as a gapless semimetal when grown on the Td-WTe2 substrate. Here, we demonstrate that interface engineering can be applied to tune the interfacial charge transfer and, thus, the electron band of the epitaxial monolayer. As a result, the nearly freestanding (semiconducting) α-antimonene monolayer with a band gap of ∼170 meV was successfully obtained on the SnSe substrate. Furthermore, a semiconductor-semimetal crossover is observed in the bilayer α-antimonene. This study paves the way toward modifying the electron structure in two-dimensional vdW materials through interface engineering.

Ligand Non-innocence and Single Molecular Spintronic Properties of AgII Dibenzocorrole Radical on Ag(111).

A facile method for the quantitative preparation of silver dibenzo-fused corrole Ag-1 is described. In contrast to the saddle conformation resolved by single-crystal X-ray analysis for Ag-1, it adopts an unprecedented domed geometry, with up and down orientations, when adsorbed on an Ag(111) surface. Sharp Kondo resonances near Fermi level, both at the corrole ligand and the silver center were observed by cryogenic STM, with relatively high Kondo temperature (172 K), providing evidence for a non-innocent AgII -corrole.2- species. Further investigation validates that benzene ring fusion and molecule-substrate interactions play pivotal roles in enhancing Ag(4d(x2 -y2 ))-corrole (π) orbital interactions, thereby stabilizing the open-shell singlet AgII -corrole.2- on Ag(111) surface. Moreover, this strategy used for constructing metal-free benzene-ring fused corrole ligand gives rise to inspiration of designing novel metal-corrole compound for multichannel molecular spintronics devices.

Metabolomics Analysis of the Effect of Hydrogen-Rich Water on Myocardial Ischemia-Reperfusion Injury in Rats.

To investigate the effect of hydrogen-rich water on myocardial tissue metabolism in a myocardial ischemia-reperfusion injury (MIRI) rat model. Twelve rats were randomly divided into a hydrogen-rich water group and a control group of size 6 each. After the heart was removed, it was fixed in the Langendorff device, and the heart was perfused with 37 °C perfusion solution pre-balanced with oxygen. The control group was perfused with Kreb's-Ringers (K-R) solution, and the hydrogen-rich water group was perfused with K-R solution + hydrogen-rich water. Liquid Chromatograph Mass Spectrometer (LC-MS) analysis platform was used for metabolomics research. Principle component analysis (PCA), partial least squares discriminant analysis (PLS-DA), orthogonal partial least squares discriminant analysis (OPLS-DA), Variable importance in projection (VIP) value of OPLS-DA model (threshold value ≥1) were employed with independent sample T Test (p < 0.05) to find differentially expressed metabolites, and screen for differential metabolic pathways. VIP (OPLS-DA) analysis was performed with T test, and the metabolites of the control group and the hydrogen-rich water group were significantly different, and the glycerophospholipid metabolism was screened. Seven myocardial ischemia-reperfusion injury (MIRI)-related signaling pathways were identified, including glycerophospholipid metabolism, glycosylphosphatidylinositol (GPI) anchored biosynthesis, and purine metabolism, as well as 10 biomarkers such as phosphatidylcholine, phosphatidylethanolamine and phosphatidylserine. Hydrogen-rich water regulates the metabolic imbalance that could change MIRI myocardial tissue metabolism, and alleviate ischemia-reperfusion injury in isolated hearts of rats through multiple signaling pathways.

Erratum: Realization of a Metallic State in 1T-TaS_{2} with Persisting Long-Range Order of a Charge Density Wave [Phys. Rev. Lett. 123, 206405 (2019)].

This corrects the article DOI: 10.1103/PhysRevLett.123.206405.

A Cross-Cultural Comparison of an Extended Planned Risk Information Seeking Model on Mental Health Among College Students: Cross-Sectional Study.

BACKGROUND: Approximately 42.5 million adults have been affected by mental illness in the United States in 2013, and 173 million people have been affected by a diagnosable psychiatric disorder in China. An increasing number of people tend to seek health information on the Web, and it is important to understand the factors associated with individuals' mental health information seeking. Identifying factors associated with mental health information seeking may influence the disease progression of potential patients. The planned risk information seeking model (PRISM) was developed in 2010 by integrating multiple information seeking models including the theory of planned behavior. Few studies have replicated PRISM outside the United States and no previous study has examined mental health as a personal risk in different cultures. OBJECTIVE: This study aimed to test the planned risk information seeking model (PRISM) in China and the United States with a chronic disease, mental illness, and two additional factors, ie, media use and cultural identity, among college students. METHODS: Data were collected in both countries using the same online survey through a survey management program (Qualtrics). In China, college instructors distributed the survey link among university students, and it was also posted on a leading social media site called Sina Weibo. In the United States, the data were collected in a college-wide survey pool in a large Northwestern university. RESULTS: The final sample size was 235 for the Chinese sample and 241 for the US sample. Media use was significantly associated with mental health information-seeking intentions in the Chinese sample (P<.001), and cultural identity was significantly associated with intentions in both samples (China: P=.02; United States: P<.001). The extended PRISM had a better model fit than the original PRISM. CONCLUSIONS: Cultural identity and media use should be considered when evaluating the process of mental health information seeking or when designing interventions to address mental health information seeking.

Effect of hydrogen-rich water on the Nrf2/ARE signaling pathway in rats with myocardial ischemia-reperfusion injury.

The effects of hydrogen-rich water on oxidative stress via the Nrf2/ARE signaling pathway were studied in rats with myocardial ischemia-reperfusion injury (MIRI). Sixty rats were randomly divided into a hydrogen-rich water group and a control group, with 30 rats in each group. The two groups were randomly divided into three groups: pre-ischemic period, ischemic period and reperfusion period. After the heart was removed, it was fixed in a Langendorff device and perfused with an oxygen-balanced 37 °C perfusate. The control group was perfused with Kreb's-Ringers (K-R) solution, and the hydrogen-rich water group was perfused with K-R solution + hydrogen-rich water. The levels of mRNA and protein of Nrf2, NQO1, HO-1 and SOD-1 in cardiomyocytes were detected by RT-qPCR, immunohistochemistry (IHC) and Western blot analysis. SOD activity and MDA content were determined. Hydrogen-rich water increased the activation of the Nrf2/ARE signaling pathway, and the levels of mRNA and protein Nrf2, NQO1, HO-1 and SOD-1 were significantly increased (P < 0.05) in the ischemia-reperfusion period compared with the ischemic period. In the control group, the levels of mRNA and protein of Nrf2, NQO1, HO-1 and SOD-1 were significantly decreased (P < 0.05) in the ischemia-reperfusion period compared with the ischemic period. Compared with the ischemic period, the ischemia-reperfusion phase showed significantly increased SOD activity and significantly decreased MDA content in the hydrogen-rich water group, while SOD activity was significantly decreased, and MDA content was significantly increased in the control group (P < 0.05). Hydrogen-rich water can activate the Nrf2/ARE signaling pathway, alleviate ischemia-reperfusion injury in isolated rat hearts and reduce the oxidative stress level of myocardial tissue.

Realization of a Metallic State in 1T-TaS_{2} with Persisting Long-Range Order of a Charge Density Wave.

Metallization of 1T-TaS_{2} is generally initiated at the domain boundary of a charge density wave (CDW), at the expense of its long-range order. However, we demonstrate in this study that the metallization of 1T-TaS_{2} can be also realized without breaking the long-range CDW order upon surface alkali doping. By using scanning tunneling microscopy, we find the long-range CDW order is always persisting, and the metallization is instead associated with additional in-gap excitations. Interestingly, the in-gap excitation is near the top of the lower Hubbard band, in contrast to a conventional electron-doped Mott insulator where it is beneath the upper Hubbard band. In combination with the numerical calculations, we suggest that the appearance of the in-gap excitations near the lower Hubbard band is mainly due to the effectively reduced on-site Coulomb energy by the adsorbed alkali ions.

Correction: Hydrophobic silane coating films for the inhibition of water ingress into the nanometer pore of calcium silicate hydrate gels.

Correction for 'Hydrophobic silane coating films for the inhibition of water ingress into the nanometer pore of calcium silicate hydrate gels' by Jiao Yu et al., Phys. Chem. Chem. Phys., 2019, DOI: .

Hydrophobic silane coating films for the inhibition of water ingress into the nanometer pore of calcium silicate hydrate gels.

The super-hydrophobic nature of surfaces is greatly dependent on the interfacial molecular structure of coating materials. In this study, to understand the structure, dynamics and interfacial behavior of hydrophobic coating, molecular dynamics is utilized to study the capillary transport of water molecules through the nanometer channel of calcium silicate hydrate (C-S-H) with the interior surface impregnated with silane. The C-S-H surface is coated by connecting the bridging silicate tetrahedron with an oxygen-containing group in isobutyl-triethoxysilane (C10H24O3Si) with a silane molecule coverage rate ranging from 25% to 100%. We demonstrated that the silane coating with a coverage exceeding 25% can effectively inhibit the water molecule and detrimental ion invasion in the gel pore. The grafted silane groups reduce the number of non-bridging oxygen atoms in the surface silicate chains that provide plenty of sites to accept the H bonds from the surface water molecules. This results in the reduction of the dipole moment of the surface water molecules and transforms the hydrophilic C-S-H substrate to hydrophobic. The silane molecules, immobilized by the Si-O-Si bond on the C-S-H substrate, are protruded to the gel pore with the hydrophobic tail of branch-like isobutyl groups. It transforms the smooth surface to a lotus-leaf-like rough surface with distributed nanoscale papillae. The isobutyl groups, freely vibrating and rotating, further blocks the connectivity of the transport channel and weakens the interaction between penetrated ions and C-S-H substrates. Furthermore, spatial correlation analysis demonstrates that the immobilized silane molecules disturb the tetrahedron distribution of water molecules in the gel pore and break the hydration shell of the counter Ca ions that associate with less water molecules. The dramatic degradation of the time correlation function for the surface solution species in the presence of isobutyl-triethoxysilane exhibits that the coated C-S-H surface can repel the surface water molecules and calcium ions by weakening the H bond and the Ca-O ionic bond strength. These nanostructure results provide guidance for the construction of artificial super-hydrophobic surfaces and the design of cementing materials with controllable wettability.