Internal Hydrogen Research Articles

Study on the interactions between RS-licarbazepine and carboxyethylated cyclodextrins by electrokinetic chromatography and nuclear magnetic resonance

The interactions taking place in the enantiomeric separation of the antiepileptic drug licarbazepine by Electrokinetic Chromatography (EKC) using two carboxyethylated cyclodextrins (CE-CDs) (CE-β-CD and CE-γ-CD) as chiral selectors were investigated in this work to intend to explain the reversal in the enantiomer migration order observed depending on the CD. As these CDs were mixtures of isomers, only apparent and estimated association constants for enantiomer-CD complexes could be calculated based on EKC experiments, which agreed with the enantiomer migration order observed for CE-β-CD but not for CE-γ-CD. Additional experiments were carried out using NMR to study the stoichiometry of the complexes formed, their association constants and their structure. The construction of the corresponding Job plots, from 1H NMR titrations and intermolecular NOE interactions (between some of licarbazepine’s aromatic protons and the internal hydrogens of both CDs), permitted to conclude in the formation of 1:1 inclusion complex in both cases. Also, Scott plots for both systems were obtained showing a linear behavior for CE-β-CD while a non-linear behavior was observed for CE-γ-CD. As a result, only the apparent association constant for licarbazepine-CE-β-CD complexes was calculated (0.309 mM−1) (no significant differences between licarbazepine enantiomers were found in all NMR experiments). The structure of the complexes originated by licarbazepine and both CE-CDs was investigated. Insertion complexes were formed in each case, although some structural differences were noticed as the licarbazepine-CE-γ-CD complex would be less tight than that with CE-β-CD. Molecular dynamics (MD) simulations corroborated the structures derived from NMR results.

Evaluation of blast wave from hydrogen pipeline burst by a coupled fluid-structure-rupture approach

Coupled fluid-structure-rupture model was developed to evaluate the blast field from X65 hydrogen pipeline burst. Johnson-Cook material model was implemented considering the high strain rates of material at crack tips. Internal hydrogen decompression, outer blast wave generation and propagation, and dynamic rupture of pipeline were simulated simultaneously and validated with experiments. Results demonstrated that the crack primarily ran axially at an average speed of about 120 m/s, while the maximum speed was about 200 m/s. Due to the dynamic growth of rupture opening, the outer blast wave experienced a process of first form and then strengthened by subsequent compression waves. This makes the maximum peak overpressure along the jetting direction appears at a certain standoff distance above rupture. The blast overpressures along the jetting direction were compared and discussed with those from traditional CFD method, TNT equivalence method and Baker-Tang blast curves. It was found the effective volume to calculate the burst energy needs to be further studied. Also, new blast curves were required for quick and rational estimation of blast overpressure from hydrogen pipeline burst.

Crystallographic texture and the mechanical properties of API 5L X70 pipeline steel designated for an arctic environment

The aim of this research is to examine the effect of roughing and finishing reductions on crystallographic texture. Three rolling conditions were applied with the same total reduction but different combinations of the roughing and finishing reductions, identified by their finishing reductions as low (X7FL), medium (X7FM), and high (X7FH). Texture measurements showed significant inhomogeneity at the centreline region that had higher intensities of Epsilon, Alpha, and Gamma fibre textures compared to the quarter-thickness and surface layers. Drop Weight Tear Test (DWTT) indicated that X7FL and X7FM specimens, with a relatively higher fraction of texture components of {332}<113>, Gamma fibre, and Transformed Copper (TC), exhibited superior low-temperature impact toughness compared to the X7FH steel. The electrochemical hydrogen charging experiments showed that the internal hydrogen cracks appeared only in X7FL and X7FM steels due to the large presence of detrimental {001} grain orientation on surface layer, perpendicular to ND.

Theoretical investigation on the mechanism and kinetics of the OH•‒initiated atmospheric degradation of p-chloroaniline: Addition of [formula omitted] and isomerization of peroxy radicals

Atmospheric oxidation of the p-chloroaniline-OH• adduct [C6H4ClNH2–OH]• (AD-C2) by ∑g−3O2 and internal isomerization processes of peroxy radical [C6H4ClNH2–OH]•-O2 are theoretically investigated at the M06-2X/aug-cc-pVTZ and CBS-QB3//M06-2X/aug-cc-pVTZ level of theories. Potential energy surfaces (PESs) for the most efficient pathways indicated that the oxidation process begins via the complexation of individual reactants in syn mode forming PRCy-iOO-syn (y = 2,5) in an exothermic and endogenic step. The syn mode addition is favored over the anti one due to the formation of internal hydrogen bond between the hydroxyl and peroxy groups. Formation of new C5–OO bond in PRCy-iOO-syn complex is an unimolecular process which is exothermic and exoergic. This pathway is predominated over other internal conversions due to the presence of stronger intramolecular hydrogen bond. Cyclization of the produced [C6H4ClNH2–OH]•-O2 peroxy radical AD-C2-5OO-syn into the bicyclic peroxy radical AD-C2-5,6OO-syn is the last step which is strongly endothermic and endogenic. The rate coefficients are calculated by means of the RRKM theory over the temperature range 250–350 K and at a pressure range of 0.1 bar to the high-pressure limit. The RRKM rate coefficients at the M06-2X/aug-cc-pVTZ level for the first bimolecular and last unimolecular steps are in order of 10−16 cm3 molecule−1 s−1 and 10−7 s−1, respectively, while the obtained rate coefficients at the CBS-QB3//M06-2X/aug-cc-pVTZ are overestimated about two order of magnitude.

Modelling of hydrogen distribution at the fatigue crack tip of austenitic stainless steels in internal and external hydrogen tests

A hydrogen diffusion model was developed, which accounts realistically for the kinetics of hydrogen adsorption, absorption and their reverse processes at the gas-solid interface. Using the model, the hydrogen distribution at the fatigue crack tip of austenitic stainless steels (304, 316 L) in internal and external hydrogen tests were analyzed. Results indicate that for stable austenitic stainless steel, the hydrogen concentration at the fatigue crack tip is much higher in internal hydrogen test than that in external hydrogen test, which is attributed to the extremely low adsorption, desorption and diffusion rates of γ phase. For metastable austenitic stainless steel, hydrogen rapidly enters into strain-induced α′ martensite around the fatigue crack tip, forming an enrichment peak at the α′/γ interface in external hydrogen test. While significant hydrogen outgassing occurs in α′ phase in internal hydrogen test, leading to a much lower crack tip concentration compared with external hydrogen test.

Stress corrosion cracking induced by the combination of external and internal hydrogen in Al-Zn-Mg-Cu alloy

Stress corrosion cracking (SCC) behaviors induced by the combination of external and internal hydrogen (H) in an Al-Zn-Mg-Cu alloy were systematically investigated via in-situ 3D characterization techniques. SCC of the Al-Zn-Mg-Cu alloy could initiate and propagate in the potential crack region where the H concentration exceeded a critical value, in which the nanoscopic H-induced decohesion of η-MgZn2 precipitates resulted in macroscopic cracking. External H that penetrated the alloy from the environment played a crucial role during the SCC of the Al-Zn-Mg-Cu alloy by generating gradient-distributed H-affected zones near the crack tips, which made Al alloys in water environment more sensitive to SCC. Additionally, the pre-existing internal H was driven toward the crack tips during plastic deformation. It was involved in the SCC and made contributions to both the cracks initiation and propagation.

Hydrogen Fuel Cell Technology

A hydrogen fuel cell generates energy by combining hydrogen and oxygen, making it a potential source of an electric power. The following paper presents the characteristics, operating theory, implementations, benefits, and drawbacks of the novel hydrogen fuel cell technologies available. It also covers the techniques for producing and storing hydrogen, which is the main fuel for a fuel cell. Additionally, a brief comparison of internal combustion vehicles (ICEV) and hydrogen fuel cell vehicles (FCV) is presented. The findings indicate that hydrogen fuel cell technologies have a general framework, a highperformance range of 40 to 60%, an optimal temperature range of 70 to 1000oC, and a reduced natural effect. At the end, a comparative study of five major power generating system is also performed.

Hydrogen Fuel Cell Technology

A hydrogen fuel cell generates energy by combining hydrogen and oxygen, making it a potential source of an electric power. The following paper presents the characteristics, operating theory, implementations, benefits, and drawbacks of the novel hydrogen fuel cell technologies available. It also covers the techniques for producing and storing hydrogen, which is the main fuel for a fuel cell. Additionally, a brief comparison of internal combustion vehicles (ICEV) and hydrogen fuel cell vehicles (FCV) is presented. The findings indicate that hydrogen fuel cell technologies have a general framework, a highperformance range of 40 to 60%, an optimal temperature range of 70 to 1000oC, and a reduced natural effect. At the end, a comparative study of five major power generating system is also performed.

Synergistic Gas Hydrate and Corrosion Inhibition Using Maleic Anhydride: N-Isopropylmethacrylamide Copolymer and Small Thiols.

Kinetic gas hydrate inhibitors (KHIs) are often used in combination with film-forming corrosion inhibitors (CIs) in oilfield production flow lines. However, CIs can be antagonistic to KHI performance. In this study, maleic anhydride-co-N-isopropylmethacrylamide copolymer (MA:NIPMAM) and its derivatives were successfully synthesized and tested for gas hydrate and corrosion inhibition. KHI slow constant cooling (1 °C/h) screening tests in high-pressure rocking cells with synthetic natural gas and CO2 corrosion bubble tests in brine were performed in this study. The results revealed that underivatized MA:NIPMAM in water (as maleic acid:NIPMAM copolymer) showed poor KHI performance, probably due to internal hydrogen bonding. However, derivatization of MA:NIPMAM with 3-(dibutylamino)-1-propylamine (DBAPA) to give MA:NIPMAM-DBAPA gave excellent gas hydrate inhibition performance but only weak corrosion inhibition performance. Unlike some KHI polymers, MA:NIPMAM-DBAPA was compatible with a classic fatty acid imidazoline CI, such that neither the KHI polymer performance nor the corrosion inhibition of the imidazoline was affected. Furthermore, excellent dual gas hydrate and corrosion inhibition was also achieved in blends of MA:NIPMAM-DBAPA with small thiol-based molecules. In particular, the addition of butyl thioglycolate not only gave excellent corrosion inhibition efficiency, better than adding the fatty imidazoline, but also enhanced the overall gas hydrate inhibition performance.

Innovative developments on the use of hydrogen in transport internal combustion engines and power plants

BACKGROUND: Innovative technologies and design solutions aimed at using hydrogen in internal combustion engines and hydrogen power plants are reviewed in the paper. The advantages of hydrogen fuel are shown and the main problems that Western automakers face and which determine the ways to solve problems in road transport are identified. In this regard, the method of using hydrogen energy in internal combustion engines and hydrogen power plants becomes a decisive factor.&#x0D; AIMS: Search for a reasonable and effective method of using hydrogen in transport.&#x0D; METHODS: The technologies of hydrogen production with the electrolysis method and on-board generation of hydrogen using hydrogen-containing components are considered. It is proposed to use ammonia as a hydrogen carrier reagent for operation in dual-fuel diesel internal combustion engines.&#x0D; RESULTS: It is noted that ammonia, with a high level of hydrogen content in the molecule, is relatively safe, has a low cost and a significant volume of production. It is easier to store and transport compared to hydrogen. For internal combustion engines operating on hydrocarbon fuel, the use of ammonia and hydrogen, its derivative product, is attractive due to the need to remove highly toxic nitrogen oxides containing in the exhaust gases of diesel internal combustion engines.&#x0D; One of the main problems of creating an environmentally friendly diesel engine associated with reducing the NOx content to an environmentally safe level is considered. A positive factor of using ammonia is the on-board production of hydrogen in the thermal reactor, as well as the possibility of organizing an effective process of neutralizing nitrogen oxides in a diesel engine.&#x0D; CONCLUSIONS: The use of ammonia to generate hydrogen allows the diesel engine to implement the process of selective reduction of nitrogen oxides when ammonia is injected into the combustion chamber at the exhaust stroke. This method will significantly increase the efficiency of NOx neutralization in a diesel internal combustion engine due to the possibility of temperature regulation of the NOx neutralization reaction directly in the cylinder and in the exhaust system of the internal combustion engine.

CrMP-Sol database: classification, bioinformatic analyses and comparison of cancer-related membrane proteins and their water-soluble variant designs

Membrane proteins are critical mediators for tumor progression and present enormous therapeutic potentials. Although gene profiling can identify their cancer-specific signatures, systematic correlations between protein functions and tumor-related mechanisms are still unclear. We present here the CrMP-Sol database (https://bio-gateway.aigene.org.cn/g/CrMP), which aims to breach the gap between the two. Machine learning was used to extract key functional descriptions for protein visualization in the 3D-space, where spatial distributions provide function-based predictive connections between proteins and cancer types. CrMP-Sol also presents QTY-enabled water-soluble designs to facilitate native membrane protein studies despite natural hydrophobicity. Five examples with varying transmembrane helices in different categories were used to demonstrate the feasibility. Native and redesigned proteins exhibited highly similar characteristics, predicted structures and binding pockets, and slightly different docking poses against known ligands, although task-specific designs are still required for proteins more susceptible to internal hydrogen bond formations. The database can accelerate therapeutic developments and biotechnological applications of cancer-related membrane proteins.

Bifunctional hydrophobic deep eutectic solvents for selective recovery of Sm and Co from waste SmCo permanent magnets

The application of hydrophobic deep eutectic solvent (HDES) to single-use separation of valuable metal ions in waste samarium-cobalt permanent magnets has been a significant challenge. Trioctylphosphine oxide and 3-benzoyl-1,1,1-trifluoroacetone were combined to prepare a bifunctional HDES that was investigated for green, efficient and safe recovery Sm and Co. Firstly, internal hydrogen bond interaction was verified by DSC, TGA, NMR, FT-IR and molecular dynamics study. Then, a various of optimization experiments were carried out to discovery extraction behaviors on different metal ions. The findings indicated that the acidity has a significant impact on the effectiveness of the extraction process. The maximum extraction capacities were measured as 98.8 g/L Sm(III), 64.8 g/L Co(II), 52.4 g/L, Fe(III) and 75.1 g/L Cu(II), respectively. After that, combined with UV–vis, FT-IR and XPS, the neutral complex extraction mechanism was proposed. Finally, the competitive extraction experiments at different acidity provided the theoretical underpinnings for a three-stage separation strategy that, through acidity control and the use of various stripping agents, was able to efficiently recover 97.8% Sm(III), 99.1% Co(II), 99.5% Fe(III) and 95.6% Cu(II). The whole recycling process has no need additional organic solvents, enabling cleaner and sustainable engineering production.

Multifunctional Janus-type self-healing MXene/polyionic liquid flexible sensor

Integration of electronic sensors with signal processing systems is important for artificial intelligence and intelligent robots. It requires mechanically robust, highly sensitive, and self-healing sensing materials that produce recognizable electrical changes in response to external stimuli. Here, we report a multifunctional Janus-type self-healing MXene/polyionic liquid-based flexible membrane for smart sensing. Flexible MXene-NH2@PIL material with self-healing capacity and high tensile properties was constructed by compounding functionalized MXene with polyionic liquid (PIL) with self-healing ability. Deposition of MXene-NH2 resulted in MXene-NH2@PIL with a unique Janus structure that exhibits a variation in the degree of hydrophilicity on both sides and a certain pH response. The material, which can be warmed to over 70 °C in 8 s, also has excellent photothermal conversion. The internal ionic and hydrogen bonding interactions ensure that it can repair damage at 60 °C. The flexible MXene-NH2@PIL sensor prepared from this material can produce significant signal changes in response to small deformations, such as knocks. The flexible MXene-NH2@PIL sensor can also be worn on the finger to detect the bending motion of the finger. This provides an idea for the preparation of self-healing flexible wearable sensors. This study explores the preparation of flexible self-healing sensors by combining the electron-conducting MXene material and ion-conducting PIL.

Research on residual stress and hydrogen diffusion of X80 pipeline welded joint

Hydrogen enrichment induced by pipeline welding residual stress is a key issue affecting the safe service of hydrogen pipelines. In order to explore the influence of welding residual stress on hydrogen diffusion and the effect of heat treatment, an X80 pipeline model with a six-layer girth weld was established using ABAQUS software, and coupling analysis of temperature field, stress field, and hydrogen diffusion was carried out. The distribution of residual stress in the welding area and local inclusion area was analyzed, the relationship between the hydrostatic stress and hydrogen diffusion of the pipeline, and the influence of the direction and shape of the inclusion on hydrogen diffusion were explored, and the effect of post-weld heat treatment on the residual stress and hydrogen diffusion in the welding area and local inclusion area was studied. The hydrostatic stress curve is similar to the hydrogen concentration distribution curve, and hydrostatic stress can be considered the main driving force for hydrogen diffusion in the pipeline. As the angle between the inclusions and the hydrogen diffusion direction increases, the hydrogen diffusion flux will gradually decrease. The more slender the inclusions, the stronger the diffusion ability of parallel or 45° inclusions, and the weaker the diffusion ability of perpendicular inclusions. Hydrogen enrichment occurs in inclusions or inclusion boundaries before and after post-weld heat treatment of the pipeline, and the internal hydrogen concentration of hard inclusions is higher than that of soft inclusions. Post-weld heat treatment can significantly reduce welding residual stress and hydrostatic stress, thereby reducing hydrogen enrichment concentration.

Novel porous CaO-MgO-promoting γ-Al2O3-catalyzed selective hydrogenation of oleic acid to green hydrocarbon fuels in biogasoline range with methanol as an internal hydrogen source

An efficient and highly selective CaO-MgO-promoting γ-Al2O3 decarboxylation catalyst was fabricated with different CaO to MgO ratios via a ball-milling method for regulating product distribution and production of gasoline-kerosene-diesel hydrocarbons via the catalytic copyrolysis of oleic acid (OA) and methanol under hydrogen-generating conditions. In addition, influencing factors, reaction mechanisms, possible reaction pathways and deactivation mechanisms were probed. The results showed that combining Ca, Mg and AlOx was vital for boosting oleic acid conversion, and synergy between metal and acid active sites via strong metal-support interactions enhanced deoxygenation-cracking activity. High-alkalinity CaO boosted C-C/CC bond cleavage, and MgO provided medium-strength Lewis acid sites; additionally, a large BET surface area and mesopore volume suppressed excessive hydrocracking reactions, improving biogasoline yield. Methanol addition provided active hydrogen atoms to enhance biogasoline selectivity at the expense of diesel and heavy oil production via olefinic cycles and aromatic cycle mechanisms and reduced coke deposition. The maximum hydrocarbon and biogasoline yields of 94.53% and 57.59% were achieved at OA/methanol= 5:1 and pyrolysis/catalytic temperature= 450/500 °C with1 g catalyst at a feedstock input rate of 0.1 ml/min.

Construction and mechanism study of lignin-based polyurethane with high strength and high self-healing properties

Lignin is a natural polymer with abundant functional groups with great application prospects in lignin-based polyurethane elastomers with self-healing abilities. In this study, a lignin self-healing polyurethane (PUDA-L) was specially designed using lignin as the raw material of polyurethane, combining lignin with Diels-Alder (DA) bond and hydrogen bonds. The experimental results showed that PUDA-L was prepared with good thermal stability, fatigue resistance, shape memory effect, excellent mechanical strength, and self-healing ability by partially replacing the crosslinking agents with bio-based lignin and hydroxylated modified lignin to increase the hydroxyl content. Polyurethane has a tensile strength of up to 29 MPa and an elongation at break of up to 500 %. The excellent self-healing ability of PUDA-L originates from the internal DA bonds and cross-linked hydrogen bonds. After the dumbbell sample was fused and heated at 130 °C for 4 h, the elastomer could be completely healed, the tensile strength was restored to 29 MPa, and the self-healing efficiency was up to 100 %. The developed PUDA-L elastomer has promising applications in sensors and smart skins.

Hydrogen embrittlement in high strength fasteners: Comparison between bainitic and tempered martensitic steels

The scope of this work is to explore innovative microstructure typologies, as well as heat treatments, for the manufacturing of high-strength steel fasteners aimed at obtaining a reduced susceptibility to hydrogen embrittlement. The research evaluates the role of microstructure and the notch tensile strength (RNTS) in relation to the geometry tested on hydrogen embrittlement of steels used in fasteners production. High-strength steel fasteners are increasingly used especially in Automotive industry to mechanically join parts together, increase vehicle performance and promote car weight reduction. High-strength steel fasteners, included in property class 12.9 and higher, are characterized by an ultimate tensile strength above 1200 MPa, despite the remarkable mechanical performance they are historically prone to hydrogen embrittlement phenomena. The phenomenon of hydrogen embrittlement is widely investigated, characterized by its unpredictability and its ability to result in brittle fractures. In this study, slow strain rate tensile tests were conducted to investigate and compare the effect of internal hydrogen concentration on the mechanical properties of fasteners with martensitic microstructure in property classes 10.9and 12.9, as well as innovative high strength fasteners with bainitic microstructure in property class 12.9U.The commonly utilized methodologies for assessing hydrogen embrittlement in fasteners are standardized procedures primarily focused on mechanical tests conducted on finished fasteners. They do not effectively differentiate the influence of surface treatment from material selection and fastener design. For this reason, during the present research, a simpler, faster and very promising methodology has been used. This procedure could be the basis for developing a new Standard guideline for prevention of hydrogen delayed fracture. Additionally, SEM fractography has been interpreted according to the well-known HELP and HEDE models.

A quantum chemical and kinetics study on the unimolecular reactions of fuel radicals formed during the oxidation of n‐propylamine

AbstractThe major intermediate product under co‐combustion conditions of hydrocarbon fuels with ammonia are amines. Herein, we have theoretically investigated the unimolecular reactions of fuel radicals formed during the oxidation of n‐propylamine. Quantum chemical calculations were performed to obtain the optimized structures and vibrational frequencies of reactants, products, and transition states at the B3LYP/aug‐cc‐pVTZ theory level. CCSD(T) single point energy calculations with the basis sets of aug‐cc‐pVDZ and aug‐cc‐pVTZ were further performed against the optimized structures, and the energies were extrapolated into infinite basis limit. Pressure‐dependent rate constants were calculated using Rice–Ramsperger–Kassel–Marcus/master equation analysis. The major reaction pathways for the fuel radicals were found to be β‐scission reactions at CC or CN bonds, and minor pathways were internal hydrogen shift and β‐scission reactions at CH or NH bonds. The calculated reaction rate constant trends were attributed to the decrease in CC and CN bond dissociation energies due to substitution effects from the amino group.

Electrifying light commercial vehicles for last-mile deliveries: Environmental and economic perspectives

The COVID-19 pandemic has led to a surge in online shopping and home deliveries, driving the demand for delivery vehicles. Last-mile delivery vehicles are one of the rampant carbon dioxide emitters, with zero-direct emission alternatives as the glaringly obvious solution to this problem. To address this issue, we present a comprehensive evaluation of the total cost of ownership (TCO) and life cycle environmental impacts of three types of light commercial vehicles (LCVs): internal combustion engine, battery electric (BE), and hydrogen fuel cell (FC) electric LCVs in Germany and California. In this study, we present the first analysis of the life cycle impacts of an FC-LCV with a lower fuel cell system power but a larger traction battery capacity referred to as a "Mid-FC" vehicle configuration. In addition, the research establishes various scenarios to examine the effect of a greener electricity grid and hydrogen produced from water electrolysis on the overall LCV life cycle impacts. Results suggest that BE LCVs are already cost-competitive in both the studied regions. Replacing a diesel LCV with a BE alternative can reduce greenhouse gas emissions by 15%–48% over the LCV's lifetime and up to 69% in a low-carbon grid scenario. The study also found that a Mid-FC LCV has lower environmental impacts than an FC counterpart if the hydrogen is produced via water electrolysis powered by low-carbon electricity. These findings provide critical insights for fleet operators seeking to balance cost-effectiveness and environmental sustainability in their LCV selection.

Investigation of Molecular Interactions Mechanism of Pembrolizumab and PD-1.

Human programmed cell death protein 1 (PD-1) is a checkpoint protein involved in the regulation of immune response. Antibodies are widely used as inhibitors that block the immune checkpoint, preventing strong immune responses. Pembrolizumab is an FDA-approved IgG4 antibody with PD-1 inhibitory ability for the treatment of melanoma. In this study, we investigated the effect of Pembrolizumab on the conformational changes in PD-1 using extensive molecular modeling and simulation approaches. Our study revealed that during the 200 ns simulation, the average values of the solvent accessible surface area, the radius of gyration, and internal hydrogen bonds of PD-1 were 64.46 nm2, 1.38 nm and 78, respectively, while these values of PD-1 in the PD-1/Pembrolizumab complex were 67.29 nm2, 1.39 nm and 76, respectively. The RMSD value of PD-1 gradually increased until 80 ns and maintained its stable conformation at 0.32 nm after 80 ns, while this value of PD-1 in the PD-1/Pembrolizumab complex maintained an increasing trend during 200 ns. The interaction between PD-1 and Pembrolizumab led to a flexible but stable structure of PD-1. PD-1 rotated around the rotation axis of the C'D loop and gradually approached Pembrolizumab. The number of hydrogen bonds involved in the interactions on the C and C' strands increased from 4 at 100 ns to 7 at 200 ns. The strong affinity of Pembrolizumab for the C'D and FG loops of PD-1 disrupted the interactions between PD-1 and PD-L1. Inhibition of the interaction between PD-1 and PD-L1 increased the T cell activity, and is effective in controlling and curing cancer. Further experimental work can be performed to support this finding.