柔顺剂对织物防水性能的影响研究OA北大核心

Waterproof fabrics are widely utilized in various fields such as outdoor sports,military equipment,and special work environments due to their unique water-resistant properties.However,the use of fabric softeners during the washing process may negatively impact the water-repellent performance of these fabrics.This study investigates the influence of fabric softeners on the hydrophobic properties of waterproof fabric surfaces and elucidates the underlying mechanisms at the molecular level.Two ester-based quaternary ammonium salts were selected as fabric softeners,and physical experiments and computational simulation methods were employed to study their adsorption behavior on waterproof fabric surfaces and their effects on hydrophobic properties. In the experimental section,100％ polyester waterproof fabric treated with C6 fluorinated waterproof finishing agents was used as the research subject.The fabric was subjected to various washing cycles and concentrations of fabric softeners,followed by the measurement of the static contact angle on the fabric surface using a DSA25 optical contact angle meter to assess changes in its hydrophobic properties.In the computational simulation section,Gaussian16 software combined with quantum chemical analysis was utilized to analyze the electrophilicity and electrophilic regions of the ester-based quaternary ammonium salt softeners,and their electrostatic adsorption mechanism on hydrophobic surfaces was clarifyied.Furthermore,Monte Carlo simulation methods were employed to model the adsorption of softeners on the fabric surface during the washing process.The results indicate that ester-based quaternary ammonium salt softeners readily undergo electrostatic adsorption on hydrophobic polymer surfaces,with the number of hydrophilic hydroxyl groups in the softeners being a key factor affecting their adsorption.The hydrophilic groups of adsorbed softener molecules on the hydrophobic polymer surface enhance the wettability of the fabric,leading to a decrease in hydrophobicity.To further validate the results of the experiments and computational simulations,molecular dynamics simulation methods were used to simulate the contact angle changes of water droplets on hydrophobic polymer surfaces,which were consistent with the trends observed in the experiments,thus validating the impact of fabric softeners on the hydrophobic properties of waterproof fabrics.This study not only provides a scientific basis for understanding the effects of fabric softeners on the performance of waterproof fabrics,but also offers guidance for the rational use and development of related products.In the experimental part,various washing cycles and concentrations were conducted,followed by a comparison of the fabric surface contact angles before and after washing using the contact angle test.The results showed that with an increase in washing cycles,the surface contact angle of the waterproof fabric was smaller than that before washing,regardless of whether fabric softeners were added.Particularly,the contact angle of the samples with fabric softeners added decreased more significantly,indicating that fabric softeners have a noticeable impact on the hydrophobic properties of waterproof fabrics.Quantum chemical calculations and molecular dynamics simulations were further used to analyze the adsorption behavior and mechanisms of fabric softener molecules on hydrophobic surfaces.Molecular models of fabric softeners and hydrophobic polymers were constructed,and the molecular electrostatic potential(MEP)and frontier molecular orbitals(FMO)of the fabric softeners,including the highest occupied molecular orbital(HOMO)and the lowest unoccupied molecular orbital(LUMO)were calculated.These calculations revealed the electrophilic and nucleophilic regions of the fabric softener molecules and their interactions with hydrophobic polymer surfaces.Molecular dynamics simulations were used to simulate the adsorption behavior of fabric softener molecules on hydrophobic polymer surfaces during the washing process and the changes in contact angles after adsorption.The simulation results indicated that the adsorption of fabric softener molecules significantly reduced the contact angle of water droplets,thereby decreasing the hydrophobic properties of the fabric.These findings were consistent with the experimental results,further confirming the negative impact of fabric softeners on the hydrophobic properties of waterproof fabrics. The conclusions of this study are significant for understanding and optimizing the washing process of waterproof fabrics.The results suggest that fabric softeners should be used cautiously in washing waterproof fabrics to avoid damaging their water-repellent properties.Additionally,this study provides a theoretical basis for the development of new waterproof fabrics,especially when designing and selecting fabric softeners,the impact on fabric surface properties should be considered.By gaining a deeper understanding of the interaction between fabric softeners and waterproof fabrics,more environmentally friendly and efficient washing solutions can be developed to maintain the performance of waterproof fabrics and extend their service life.In summary,this study not only enhances the understanding of the mechanisms by which fabric softeners affect the hydrophobic properties of waterproof fabrics,but also provides reference for research and applications in related fields.