Adhesion Enhancement and Characterization of Plasma Polymerized 1,2-Dichloroethane on Polypropylene Surface

Polypropylene (PP) films were modified in 1,2-dichloroethane (DCE) plasma. Surface energy measurement and rate of deposition showed two-step surface modification. First, incorporation of chloride ions on PP surface followed by deposition of cross-linked layer. DCE plasma modified PP films were subsequently compared with earlier reported work on carbontetrachloride (CCl₄) and chloroform (CHCl₃) plasma modification. Modified films were characterized using ATR-FTIR technique by monitoring the relative changes in intensities of C–H stretch vibrations. The nature of deposition on PP film was characterized using FTIR technique and solubility test. Peel strength measurements of DCE, CCl₄, and CHCl₃ plasma modified films showed improvement in bonding strength. Durability of plasma modified PP film was studied by calculating surface energy and peel strength of samples aged for two months.     

ATR-FTIR快速检验蔬菜表面残留氯氰菊酯

用FTIR、ATR技术对青菜表面残留的氯氰菊酯进行了定性、定量分析，并研究了氯氰菊酯在白菜类蔬菜表面残留情况。结果表明，ATR、FTIR测定蔬菜表面农残的灵敏度高于透射光谱法，具有快速、简便、无需预处理等优点。     

Influence of hydrolytic degradation on the surface properties of poly-5d/95l-lactide resorbable bone plates

This study explores in vitro aging effects on the surface properties of resorbable PLA95 (poly-5d/95l-lactide) bone plates. The in vitro degradation of injection molded PLA95 bone plates was undertaken by soaking them in a PBS solution. Specimens were harvested at 0, 4, 6, 8, 12, 20, and 26 weeks. After each in vitro aging period, the surface morphology, viscosity, chemical structure, wettability, and thermal properties of the PLA95 bone plates were examined by scanning electron microscopy (SEM), capillary viscometers, attenuated total reflection fourier transform infrared spectroscopy (ATR-FTIR), contact angle, and modulated differential scanning calorimetry (MDSC), respectively. The surface morphology of aged PLA95 bone plates exhibited bulk erosion. As hydrolysis progressed, the inherent viscosity (I.V.) of the PLA95 plates gradually decreased from 0.83 ± 0.01 dL/g at week 0-0.46 ± 0.03 dL/g at week 26. However, the absorbance peak intensity ratio between δ_{as CH3} (A_1452 cm⁻¹) and ν_CO (A_1750 cm⁻¹) and the contact angle reveal different tendencies than that of molecular weight, which decreases. The contact angle of the PLA95 plates decreased until week 4, increased until week 8, and subsequently decreased again. Peak separation analysis reveals that the equilibrium part of the modulated DSC overlapped curves exhibit triple endothermic peaks. Over time, in vitro degradation changes the position and area of the individual peaks. After different time periods of degradation, the variation of wettability shows a tendency similar to the change of PLA95 plates crystallinity; the intensity ratio of A_1452 cm⁻¹ and A_1750 cm⁻¹ (δ_{as CH3}/ν _CO) absorbance peaks varied like the ratio of β/α-crystal heat of fusion. Results also show a similarity in the degradation time dependence in MDSC, contact angle, and ATR-FTIR measurements. During the in vitro aging process, the breakdown and subsequent recrystallization of PLA95 molecular chains might be attributed to a progressive change in wettability and the molecular conformation between δ_{as CH3} and ν_CO.     

Offline Monitoring of Hydroxyethyl Methacrylate and 3-Dimethylaminopropyl Methacrylamide Copolymerization: Correlation Between FTIR and GC Quantifications

Attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy is classically used to monitor homopolymerizations. In this article, this analytical technique was extended to monitor the synthesis of VIVIPRINT 300, which is a copolymer of 2-hydroxyethyl methacrylate (HEMA) and N-[3-dimethylaminopropyl]methacrylamide (DMAPMA). The calibration curves devised for this study were based on the two homopolymers P(HEMA) and P(DMAPMA). A good correlation was realized between the FTIR absorbance intensities observed respectively at 1300 cm^?1 (polymerized C-O ester bond) and 1230 cm^?1 (polymerized C-N amide bond) and the level of residual HEMA and DMAPMA monomers determined by GC. Application of these calibration curves to the copolymerization also exhibited a good correlation of data relating to residual monomer determination by FTIR and GC, validating the success of this spectroscopic in situ technique.     

衰减全反射红外光谱法的高密度聚乙烯自然老化特性研究

采用衰减全反射红外光谱技术(ATR-FTIR)研究物资储备中广泛使用的滚塑包装箱专用高密度聚乙烯(HDPE),在特定湿热海洋环境的海南万宁实验站1年期内自然老化特性。定性分析老化前后化学结构变化,从断链、支化以及氧化角度区分不同阶段的老化特性,根据特征峰峰强和峰面积变化,定量分析羰基指数和相对结晶度的变化规律,探索老化前后羰基指数、相对结晶度变化与力学性能变化的相关性。结果表明：老化行为三个月内以断裂、支化为主,3~6个月氧化逐渐产生,6个月后氧化和支化占主导地位,9个月后氧化程度逐渐饱和,且老化进程与温度和辐照正相关。12个月后,羰基指数增长112倍,结晶度上升约10%,力学性能中材料拉伸/弯曲模量较拉伸/弯曲强度下降更快。老化前后羰基指数与拉伸模量变化相关系数为0.97,基于720~730 cm-1特征谱带计算的相对结晶度变化与拉伸强度变化相关系数为0.96。结果表明采用ATR-FTIR可以在快速无损检测的前提下,从老化前后化学结构的变化推测力学性能的变化。     

利用衰减全反射傅里叶红外光谱(ATR-FTIR)技术快速筛选可降解苯酚菌株

苯酚是一种重要的化工原料并广泛存在于工业废水中,随着各国对苯酚生物毒性的认识,排放标准日益提高。生物法作为一种高效、 低成本、 不易二次污染的方法常用于含酚的废水处理。但是可降解苯酚的微生物筛选却是一个复杂繁琐的过程。衰减全反射傅里叶红外光谱(attenuated total reflection Fourier transform infrared,ATR-FTIR)技术是一种高效、 快捷、 高指纹特性的物理检测技术,主成分分析联用最小偏二乘法(principal component analysis-partial least squares,PCA-PLS)是一种有效提取特征指纹峰并建立模型的方法,该实验联合ATR-FTIR检测技术和PCA-PLS统计方法建立苯酚浓度与吸光度模型,可以快速检测固体培养基中底物浓度。实验建立模型判定系数可以达到99.5%,预测集的判定系数可以到达99.4%,说明模型具有较高的拟合性和推广性。通过模型可以预测出菌株降解后固体培养基底物浓度,筛选出可降解苯酚功能微生物,传统的液体培养并采用气相色谱检测残留苯酚浓度筛选出的结果与ATR-FTIR方法筛选出结果进行对比发现,得到相同的筛选结果。结果表明ATR-FTIR联合PCA-PLS建立高拟合度模型,可以快速检测固体培养基底物浓度,从而达到快速筛选可降解苯酚菌的目的,这种方法可以应用到其他有特征指纹峰的底物中,ATR-FTIR是一种可以广泛应用到功能微生物筛选的快速检测方法。     

ATR-FTIR在研究环境固液微界面吸附过程中的应用

微界面吸附过程是许多环境微界面反应的初始步骤或关键步骤。通过原位分析方法实时研究环境微界面吸附过程,可以获得更直接的界面反应信息和更可靠的反应机制证据,对于认识污染物在环境中分配转化和迁移传输规律有着重要意义。衰减全反射红外光谱技术由于其独特的采样原理、简便的制样方法和广泛的适应性,正逐渐成为研究微界面反应的一个有力工具。本文在简要介绍原位衰减全反射红外光谱的技术原理的基础上,综述其在环境微界面吸附过程,尤其是矿物-水界面吸附过程中的应用,并探讨其在环境微界面过程研究中的发展前景。     

(NH4)2SO4，NH4NO3和(NH4)2SO4/NH4NO3混合气溶胶吸湿质量增长因子的快速测量方法

气溶胶颗粒的吸湿性决定了其尺寸、浓度、化学组成以及相态,从而显著影响着全球气候、大气异相化学以及人类健康。运用在线、原位、连续扫描衰减全反射傅里叶变换红外光谱（ATR-FTIR）技术, 结合线性湿度（RH）控制系统,实现了RH连续变化条件下气溶胶FTIR-ATR光谱的快速测量。根据水弯曲振动谱带（~1 640 cm-1）峰面积随RH的变化,得到了(NH₄)₂SO₄,NH₄NO₃和(NH₄)₂SO₄/NH₄NO₃混合气溶胶的质量增长因子（MGFs）、潮解点（DRH）和风化点（ERH）。与气溶胶的E-AIM模型预测值相比较,实验结果表现出良好的一致性,证实该方法是一种测量大气气溶胶MGFs,ERH和DRH的快速测量方法。     

Synthesis and Characterization of Sol–Gel-Derived SiO2–CaO Particles: Size Impact on Glass (Bio)Properties

Four highly bioactive glasses in a binary SiO₂–CaO system are prepared following a sol−gel method using Ca(OH)₂ as a calcium precursor. In the synthesis of glass according to the modified Stöber method, Ca(OH)₂ suspended in polyethylene glycol allows the elimination of the presence of calcite and the increase of ammonia concentration causes formation of spherical particles with different sizes in the range of 26–266 nm. The relation among the size and properties, including bioactivity, of the glass particles is evaluated. New glasses that vary in composition (10–25 wt% CaO), porosity (15–113 m² g⁻¹), and hydroxyl groups content greatly enhance the formation process of hydroxyapatite (HA) in simulated physiological fluids. For all glasses, superior apatite-mineralization ability in time as short as 2 h in the physiological-like buffer is achieved, thus exceeding the bioactivity of the known bioactive glasses, including 45S5 glass (Bioglass). The assessment of the safety and toxicity profile of the obtained glasses is verified in a wide range of concentrations (1–1000 µg mL⁻¹) against human dermal fibroblasts and MC3T3 mouse osteoblast precursors, but also to human erythrocytes by determining hemocompatibility. Two glasses of different sizes, 73 and 266 nm, are promising and warrant further research.