基于聚六亚甲基胍盐酸盐的聚丙烯酰胺/琼脂双网络抗菌水凝胶

以琼脂(Agar)、丙烯酰胺(Am)、单宁酸(TA)、氧化石墨烯(GO)为主要原料,N,N'-亚甲基双丙烯酰胺(MBA)为交联剂制备双网络水凝胶PAM-Agar-TA-GO(简称PATG),其中,TA将GO还原成还原氧化石墨烯(r GO)。然后,以TA/rGO为微反应器与聚六亚甲基胍盐酸盐(PHMG)反应,将PHMG固定于水凝胶骨架中,制备双网络抗菌水凝胶(PATGH)。对制备的水凝胶的力学性能、热力学性能、抗菌性能、抑菌性能及生物相容性进行了测试。结果表明,琼脂的加入使水凝胶的断裂伸长率提高了60%,抗压强度提高,力学性能得到提高,水凝胶内部孔隙进一步缩小;经质量分数为2.0%PHMG水溶液浸泡后得到的抗菌水凝胶对大肠杆菌和金黄色葡萄球菌的抑菌率均达到99.80%以上;抗菌水凝胶在抑菌圈测试中无明显抑菌圈形成,表明PHMG被固定于水凝胶中;红细胞(RBC)溶血实验表明,水凝胶溶血率均低于5%,抗菌水凝胶有着良好的生物相容性。     

氧化石墨烯负载纳米银/聚乙烯醇型抗菌水凝胶制备与性能

以聚乙烯醇(PVA)、氧化石墨烯(GO)、硝酸银为原料，在不添加引发剂和交联剂的情况下，使用物理交联法（冷冻-解冻法）制得系列AgNPs质量分数不同的还原氧化石墨烯（rGO）负载纳米银/聚乙烯醇型抗菌水凝胶（rGO-AgNPs/PVA）（PGA）。通过FTIR、SEM对水凝胶的结构和形貌进行了表征，通过拉力实验和生物实验对其力学性能和生物性能进行了测试。结果表明，还原氧化石墨烯的加入增强了聚乙烯醇（PVA）水凝胶的机械强度，rGO-AgNPs/PVA抗菌水凝胶断裂伸长率相较于PVA水凝胶提高约60%，拉伸应变可达到125%。流变测试表明，PVA水凝胶的储能模量（G''）和损耗模量（G''）均低于rGO-AgNPs/PVA水凝胶；rGO与纳米银(AgNPs)协同抗菌，PGA-1、PGA-2、PGA-3、PGA-4、PGA-5对大肠杆菌和金黄色葡萄球菌的抑菌带宽度分别为0.5~4.5 mm和0.5~5.5 mm；SEM测试发现，相较于PVA水凝胶，rGO-AgNPs/PVA水凝胶的孔洞增多，rGO通过π-π作用形成网络结构，rGO-AgNPs/PVA水凝胶显示出多孔互联的微观结构。     

还原氧化石墨烯负载纳米银/聚乙烯醇型抗菌水凝胶的制备与性能

以聚乙烯醇（PVA）、氧化石墨烯（GO）、硝酸银为原料,在不添加引发剂和交联剂的情况下,使用物理交联法（冷冻-解冻法）制得了一系列还原氧化石墨烯（rGO）负载不同质量分数纳米银（AgNPs）/PVA型抗菌水凝胶（rGO-AgNPs/PVA）(PGA-1～PGA-6,阿拉伯数字代表AgNPs的质量分数)。通过FTIR、SEM、TGA、电子万能材料试验机和流变仪对水凝胶的结构、形貌、力学性能和流变性能进行了表征,并对其生物性能进行了测试。结果表明,rGO的加入增强了PVA水凝胶的机械强度,rGO-AgNPs/PVA抗菌水凝胶断裂伸长率比PVA水凝胶提高约60%,拉伸应变达到125%。PVA水凝胶的储能模量和损耗模量均低于rGO-AgNPs/PVA水凝胶;rGO与AgNPs协同抗菌,PGA-3(AgNPs质量分数0.33%)对大肠杆菌和金黄色葡萄球菌的抑菌带宽度分别约为4.5和5.5 mm;相较于PVA水凝胶,rGO-AgNPs/PVA水凝胶的孔洞增多,r GO通过π-π作用形成网络结构,r GO-Ag NPs/PVA水凝胶显示出多孔互联的微观结构。     

聚氨酯-羧甲基壳聚糖席夫碱水凝胶的制备与性能

将2,4-二羟基苯甲醛（DDBA）作为扩链剂，丙烯酸羟乙酯(HEA)作为封端剂制备了含有醛基的水性聚氨酯（DPU），在温和的条件下引入羧甲基化壳聚糖（CMCh）合成了聚氨酯-CMCh席夫碱，再由自由基聚合法引入聚丙酰胺合成了聚氨酯-羧甲基壳聚糖席夫碱水凝胶（DPU-Ch）。通过FTIR、SEM、力学性能、溶胀保水试验、抗菌试验和血液相容性测试等对水凝胶结构和性能进行表征。结果表明，水凝胶的机械性能随着CMCh质量分数的增加而提升，同时水凝胶也显示出良好的溶胀能力和保水能力；当CMCh添加量为2%时，水凝胶对革兰氏阳性和阴性细菌菌株均显示出良好的抗菌性能；水凝胶溶血率均低于5%表明其具有良好的细胞相容性，NIH3T3细胞存活率在90%以上证明其没有细胞毒性，因此在生物医疗领域中具有潜在的应用前景。     

聚丙烯酸/氧化石墨烯自修复水凝胶的合成及性能

通过改进的Hummers方法成功制备了氧化石墨烯(GO)。以Fe3+为交联剂、丙烯酸(AA)为单体、GO为增强剂,采用原位聚合法制备了聚丙烯酸(PAA)/GO自修复水凝胶。考查了不同GO含量下,PAA/GO自修复水凝胶的溶胀性能,并探讨了GO含量、Fe3+含量和H2O含量对PAA/GO自修复水凝胶力学性能的影响,研究了PAA/GO自修复水凝胶的自修复性能。结果表明,Fe3+含量、GO含量和H2O单体含量分别为0.5 %（摩尔分数）、0.5 %（质量分数,下同）、80 %时,具有最佳力学性能（其拉伸强度为743.5 kPa,断裂伸长率为2940.5 %）;GO含量为0.25 %时,PAA/GO自修复水凝胶的吸水性能最大;PAA/GO自修复水凝胶具有优异的自修复性能。     

UV固化PHMG基抗菌非离子水性聚氨酯的制备与性能

通过乙二胺（GHC）和盐酸胍（GHC）熔融缩聚制备了抗菌剂聚六亚甲基胍盐酸盐（PHMG），将PHMG与甲基丙烯酸缩水甘油酯（GMA）反应制得双键官能化PHMG（MPHMG），通过FTIR、1H NMR、13C NMR和UV表征了MPHMG的成功合成；将MPHMG、光引发剂和双键封端非离子水性聚氨酯（NU）共混，待水挥发后经紫外固化得到抗菌涂层PNU。通过FTIR、TGA、拉伸、吸水率和抗菌性能测试对PNU胶膜的结构与性能进行了表征。结果表明，MPHMG会增加PNU胶膜中软段的氢键作用和亲水基团含量，当胶膜中MPHNG含量为2.0%时，其T30%和T50%分别提高了7.3℃和12.6℃，拉伸强度提高了1.6MPa，吸水率增加了6.8%。抗菌试验表明，当胶膜中MPHMG的含量大于1.0%时，接触细菌2h，对金黄色葡萄球菌和大肠杆菌的抗菌率均可以达到99.8%以上。     

金属有机骨架/聚乙烯醇双交联网络复合水凝胶的构建及其抗菌性能研究

将具有抗菌性能的金属有机骨架（MOF）材料与具有双交联网络结构的聚乙烯醇（PVA）水凝胶相结合，构建了一种具有优良力学性能和抗菌性能的MOF/PVA抗菌水凝胶复合材料。该抗菌水凝胶采用物理与化学双交联的高分子网络结构，可增强水凝胶的力学性能。水凝胶内部结合了含有Ag⁺的MOF（AMOF）颗粒和含有Zn²⁺的MOF颗粒，随着2种MOF颗粒的缓慢降解，水凝胶持续释放的Ag⁺和Zn²⁺对细菌细胞造成物理损伤，实现对革兰氏阴性与阳性细菌生长的有效抑制，抑制率高达99%以上，为新型抗菌水凝胶材料的设计和构建提供了一种新策略。     

聚丙烯酰胺/碳量子点/氧化石墨烯复合水凝胶制备及其性能分析

目前相比于只用一种物理交联剂,同时用两种物理交联剂提高复合水凝胶力学性能的研究少有报道。为了研究同时以碳量子点（CQDs）和氧化石墨烯（GO）作为多官能度物理交联剂对复合水凝胶力学性能的影响,本文首先分别用低温水热法和改进的Hummer法制备了50mg/mL 的CQDs水分散液和5mg/mL的GO水分散液。通过原位自由基聚合的方法,改变CQDs和GO用量,制备了一系列聚丙烯酰胺（PAM）类纳米复合水凝胶（PAM/CQDs/GO）。利用X射线衍射仪、拉力机和流变仪对所得的水凝胶进行表征和测试。得出当用1mL的CQDs水分散液和4mL的GO水分散液制备的PAM/CQDs/GO复合水凝胶力学综合性能最好,其断裂伸长率为3916.86%,拉伸强度为165.3kPa,杨氏模量为33.36kPa。结果表明：适量的CQDs和GO都能提高PAM/CQDs/GO复合水凝胶的多种力学性能,其中GO更有利于增大纳米复合水凝胶的拉伸强度、杨氏模量和耗散能,而CQDs更有利于增大断裂伸长率。与GO相反,CQDs的加入能提高纳米复合水凝胶的黏性、降低其刚性和再次被拉伸时的杨氏模量。通过对CQDs和GO的用量进行调节,可以制备出力学性能不同的纳米复合水凝胶,以满足不同领域的需要,拓宽水凝胶的应用范围。     

PNIPAM/锂藻土/氧化石墨烯近红外光响应水凝胶的制备及其应用初探

以锂藻土（Laponite）为交联剂、氧化石墨烯（GO）为光热转换试剂，通过N-异丙基丙烯酰胺（NIPAM）原位聚合，制备近红外光（NIR）响应水凝胶（Laponite-PNIPAM/GO）。首先考察Laponite的含量对Laponite-PNIPAM水凝胶的断裂伸长率和断裂强度的影响，并考察GO含量对Laponite-PNIPAM/GO水凝胶相关性能的影响，来确定Laponite和GO的合适含量。随后对所制备的水凝胶体积相转变温度（VPTT）及NIR响应性进行表征，并对Laponite-PNIPAM/GO水凝胶在光控流体开关及光控脱附方面的应用进行了初步探索。结果表明：Laponite-PNIPAM/GO水凝胶具有较高强度和良好的韧性, 断裂伸长率可达1100%以上，Laponite-PNIPAM/GO水凝胶的VPTT在36 ℃左右；NIR照射下，Laponite-PNIPAM/GO水凝胶能在3分钟内从20.3 ℃升温至48.5 ℃；由于Laponite-PNIPAM/GO水凝胶具有温敏性和光热效应，其具有作为光控流体开关及光控脱附的潜力。     

LED固化环氧丙烯酸酯/聚乙烯醇双网络水凝胶海洋防污涂料的研制

采用聚乙二醇二缩水甘油醚与丙烯酸反应制备了环氧丙烯酸酯（ PEGDGE-AA），然后通过 LED固化制备了 PEGDGE-AA/聚乙烯醇（ PVA）双网络水凝胶海洋防污涂层，探讨了 PEGDGE-AA与 PVA配比对防污涂层的力学性能及吸水溶胀性能的影响，并研究了防污涂层在人工海水中对硅藻生长的影响和抗硅藻附着性能。结果表明： PEGDGE-AA/PVA双网络水凝胶的拉伸强度高于 PVA单网络水凝胶，且随 PEGDGE-AA含量的增加，双网络水凝胶拉伸强度及弹性模量增加，断裂伸长率下降，吸水率下降，其中 PEGDGE-AA10PVA5双网络水凝胶的拉伸强度最高，拉伸强度在 570 kPa左右，弹性模量为 12. 7 kPa，断裂伸长率为 47. 0%。人工海水模拟实验结果证明，水凝胶涂层的存在对小新月菱型藻的生长基本无影响，但能阻碍其附着在涂层表面，所制备的 PEGDGE-AA/PVA双网络水凝胶具有较好的海洋防污能力。     

Biodegradable aliphatic–aromatic polyester with antibacterial property

Fast acting antibacterial property was introduced to aliphatic–aromatic polyester in the present work without sacrificing its compostability, thermal stability, and mechanical properties. Antibacterial poly(hexamethylene guanidine) hydrochloride (PHMG) was melt mixed with poly(butyleneadipate‐co‐terephthalate) (PBAT, also called Ecoflex) using a twin‐screw extruder in different amounts. The non‐reactive blending and uniform mixing was confirmed by nuclear magnetic resonance, gel permeation chromatography, scanning electron microscopy, and energy‐dispersive X‐ray spectroscopy analysis. The influence of antibacterial agent on compostability, mechanical properties, and thermal stability was studied. The presence of PHMG changed slightly the degradation profile of Ecoflex retaining the extent of degradation almost the same. The antibacterial PBAT showed high thermal stability (degradation starts around 330°C), stress at break 17–20 MPa, modulus 89–127 MPa, and elongation at break more than 700% depending upon the amount of PHMG. The combination of antibacterial activity with biodegradability makes this material a very interesting candidate for many different applications including packaging. POLYM. ENG. SCI., 56:1146–1152, 2016. © 2016 Society of Plastics Engineers     

Acrylonitrile copolymers containing guanidine oligomer: Synthesis and use for the preparation of nonleaching antimicrobial acrylic fibers

Nonleaching acrylic fibers with permanent antibacterial activity were prepared via a combination of copolymerization and a wet‐blend‐spinning method. Specifically, poly[acrylonitrile‐co‐modified poly(hexamethylene guanidine hydrochloride)] [poly(AN‐co‐M‐PHMG)] copolymers containing a covalently connected antibacterial guanidine oligomer were first synthesized via the precipitation copolymerization of acrylonitrile (AN) with a modified poly(hexamethylene guanidine hydrochloride) (M‐PHMG) macromonomer in water. Then, modified acrylic fibers were prepared from a mixture of the copolymer and commercial fiber‐grade AN terpolymer via a wet‐spinning process with dimethyl sulfoxide as the solvent. The influences of the reaction time, temperature, pH value of the medium, and amount of initiator on the copolymerization and the effect of the copolymer content on the mechanical properties and antibacterial activity of the modified acrylic fibers were investigated in detail. The results show that the M‐PHMG macromonomer exhibited a lower reactivity than AN. The poly(AN‐co‐M‐PHMG) copolymer with a PHMG content of 5.49% and an intrinsic viscosity of 11.2 dL/g could be synthesized under optimized conditions. With increasing copolymer content, the tensile strength of the modified acrylic fibers decreased slightly, and the antibacterial activity increased. The modified acrylic fibers with a copolymer content of 50% (i.e., a PHMG content of 2.75%) exhibited both good mechanical properties and excellent antibacterial activity. The additional antibacterial function would surely enlarge the applications of the fiber. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

High strength and bioactivity polyvinyl alcohol/collagen composite hydrogel with tannic acid as cross-linker

Hydrogels have great potential applications in biomedical materials, but their applications in complex physiological environments are severely limited by their weak strength and biotoxicity. Generally, synthetic polymer hydrogels and natural polymer hydrogels have complementary advantages in terms of mechanical strength and biological activity. Herein, tannic acid (TA), a natural material, was introduced into the polyvinyl alcohol/collagen (PVA-COL) double network to prepare a hydrogel (PVA-COL-TA) with good bioactivity and mechanical properties. The tensile strength of the composite hydrogel can reach up to 20 times that of the pure PVA hydrogel. And the hydrogel after swelling under physiological conditions also exhibits stable mechanical properties. The introduction of TA can reduce the degradation rate of COL, enabling it to continue to exert biological activity. in vitro cytocompatibility experiments showed that PVA-COL-TA hydrogel has good sustained biological activity and the potential for biomedical materials.     

负载白芨多糖的PU/PAM双网络水凝胶的制备与性能

采用聚乙二醇、Ymer N120、聚丙二醇和异佛尔酮二异氰酸酯为原料,以三乙醇胺作交联剂合成聚氨酯(PU)预聚物,浸入白芨多糖(BSP)和丙烯酰胺(AM)混合溶液,通过自由基聚合制备了负载BSP的PU/PAM双网络水凝胶.采用FTIR、SEM对水凝胶的结构和形貌进行了表征,通过拉力试验机和生物实验对其力学性能和生物性能进行了测试.结果表明,当三乙醇胺用量为多元醇物质的量的60％时,双网络水凝胶具有高溶胀率(256％)的同时保持一定的拉伸强度(1.9 MPa)和高压缩强度(22.7 MPa).双网络水凝胶具有抗菌抗氧化作用,其中,双网络水凝胶对大肠杆菌和金黄色葡萄球菌的抑菌带宽度分别为0.5～4.0和0.5～3.5 mm,羟基自由基清除率最高为28％;溶血率低于5％,细胞存活率最高达101.3％±3.6％,表明双网络水凝胶具有良好的生物相容性.     

The effects of graphene oxide on the properties and drug delivery of konjac glucomannan hydrogel

Konjac glucomannan (KGM) hydrogel has good potential application in food and medical science, although to achieve this, the physical and mechanical properties need further improvement. In this study, graphene oxide (GO) was used to improve the functionality of KGM hydrogel. KGM/GO hydrogels were prepared by freezing the alkaline KGM/GO sols. Rotational rheometer was used to study the rheological properties of different alkaline KGM/GO sols. Fourier transform infrared, Raman, differential scanning calorimetry, thermogravimetric analyses, and scanning electron microscopy were used to evaluate the structure and properties of the hydrogels. In addition, different pH solutions and an in vitro assay were used to study the swelling property and the release behavior of KGM/GO hydrogels, respectively. The result revealed strong hydrogen‐bond interaction between KGM and GO. The incorporation of GO highly improved the gel properties of KGM/GO sol, higher thermal stability, and more compact structure of KGM/GO hydrogels. KGM/GO hydrogels showed better swelling properties in deionized‐distilled water and pH 7.2 PBS. The release of 5‐aminosalicylic acid (5‐ASA) from KGM/GO (KG4) hydrogel was different in various pH media, but the initial burst release effect was very severe. Therefore, incorporation of GO have a good potential in enhancing the properties of KGM hydrogel, but KGM/GO hydrogel is not an ideal carrier for 5‐ASA release. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45327.     

Strengthening mechanism of poly(acrylamide)/graphene oxide/laponite dual nanocomposite hydrogels

Laponite or graphene oxide (GO) is usually used as a multifunctional crosslinker or a nanofiller to improve the nanocomposite gel strength. To explore the strengthening mechanism of GO/Laponite‐based dual nanocomposite hydrogels, we synthesized a dual nanocomposite hydrogel through in situ polymerization of acrylamide (AM) in the dispersion of GO and Laponite. The interactions between GO and Laponite were confirmed by rheological test. GO and Laponite nanosheets were exfoliated well and dispersed uniformly in the hydrogels at low concentration of GO. Crosslinking network and thermal behaviors were investigated with respect to the concentration of GO and Laponite. The gel exhibited a high mechanical strength of 391 kPa with extensibility of 1420% and a high toughness of 2.58 MJ/m³, which was expected to be applied in biological engineering field. GO is not a much more effective agent than Laponite due to formation of GO aggregates in high concentration of GO. This work provides a guidance for the synthesis of tough dual nanocomposite hydrogels. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44963.     

A polyacrylamide hydrogel for application at high temperature and salinity tolerance in temporary well plugging

In addition to conventional approach to ensure the successful application of polymer hydrogels in maintaining temporary well plugging, exact analysis of gel formation and gel strength properties in wellbore are necessary. In this work, bottles and rheology tests are used to investigate the polymer hydrogel gelation time and cross-linking kinetics of sol–gel systems which consist of polyacrylamide and chromium acetate hydroxide as a cross-linker. The effects of temperature of 90 °C and pressure of 3000 psi (typical Iranian oil well condition) were studied in relation to gelation time, strength and the mechanical properties of the hydrogel. The average molecular weight of the polymer chains between cross-link ties was evaluated using an oil-well laboratory system and compressive strength test. Differential scanning calorimeter (DSC) analysis of dried gel and the effect of temperature on the kinetics of the gel swelling in different solutions such as distilled water, tap water, formation water and oil were studied. The results showed that the number of tie points between each entanglement has not much reduced under pressure. Therefore, the prepared hydrogel can maintain its chemical structure under the Iranian oil well pressure and can be proposed to field studies. The degree of sol–gel reaction of prepared hydrogel and the activation energy based on the Arrhenius equation were calculated to be 1.5 and 274 kJ/mol, respectively.     

Preparation and characterization of graphene‐agar and graphene oxide‐agar composites

Biodegradable counterparts of petro plastics for packaging applications are highly desired due to environmental considerations. Agar can be a potential material due to its availability and biodegradability. However, moderate mechanical strength and thermal stability, in addition to poor resistance against water, needs to be addressed before agar can be commercially implemented as packaging material. As a step toward this objective, graphene oxide (GO) and reduced GO (RGO) were incorporated in agar and were solution casted in the form of films. The tensile strength was increased by 118.4% and 69.4% at 2% GO and 2% RGO loading, respectively. Higher interfacial bonding between GO and agar compared to that of RGO and agar was attributed for the observed mechanical properties. Resistance to swelling and hydrophobicity (contact angle) of the composite were improved as well when compared to pure agar. The tensile strength and the contact angle values were however, decreased after the addition of 2% GO and 2% RGO. The morphological investigation showed that the formation of pores at higher concentration of reinforcement was the contributing factor for the decrease in tensile strength. No significant change in thermal properties was observed. The transmittance value was reduced to 0% after the incorporation of GO and RGO. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45085.