A Mini-review for the Application of Bacterial Cellulose-based Composites

Countries are duly focusing more on biomass resources because of the increasing oil crisis.Owing to their excellent properties,such as natural characteristics,good mechanical performance,and outstanding chemical properties,cellulose-based materials are highly valued as promising bioderived nanomaterials,especially bacterial cellulose(BC).The main advantage lies in eliminating the problem of removing lignin and hemicellulose from woody cellulose.Moreover,the use of BC reduces the consumption of wood,the excessive use of which aggravates global warming.Herein,we summarize the applications of BC composites in filter,medical,and conductive materials,and other fields.This review contributes to further expand the applications of this renewable polymer.

Removing Cd^(2+) by Composite Adsorbent Nano-Fe_3O_4/Bacterial Cellulose

A new composite adsorbent, nano-Fe3O4/bacterial cellulose（BC）, was prepared through blending method. The process of adsorbing Cd2＋ including its isotherm and kinetics measured was studied. The results show that the adsorption efficiency is improved because of huge surface area and surface coordination of nano-Fe3O4 particles. Its adsorption capacity is 27.97 mg/g and the maximum of Cd2＋ removal is 74%. The adsorption kinetics can be described by pseudo-second rate model and the adsorption equilibrium by Langmuir type. The superparamagnetism of nano-Fe3O4 particles can help to solve the difficult separation of single BC adsorbent and lead to the quick separation of composite adsorbent from the liquid if a magnetic field was applied. Cd2＋ can be desorbed effectively by EDTA and HCl from the composite adsorbent, which can make it be reused.

Bacterial Cellulose Composite Solid Polymer Electrolyte With High Tensile Strength and Lithium Dendrite Inhibition for Long Life Battery

The development of metallic lithium anode is restrained by lithium dendrite growth during cycling.The solid polymer electrolyte with high mechanical strength and lithium ion conductivity could be applied to inhibit lithium dendrite growth.To prepare the high-performance solid polymer electrolyte,the environment-friendly and cheap bacterial cellulose(BC)is used as filler incorporating with PEO-based electrolyte owing to good mechanical properties and Li salts compatibility.PEO/Li TFSI/BC composite solid polymer electrolytes(CSPE)are prepared easily by aqueous mixing in water.The lithium ion transference number of PEO/Li TFSI/BC CSPE is 0.57,which is higher than PEO/Li TFSI solid polymer electrolyte(SPE)(0.409).The PEO/Li TFSI/BC CSPE exhibits larger tensile strength(4.43 MPa)than PEO/Li TFSI SPE(1.34 MPa).The electrochemical window of composite electrolyte is widened 1.43 V by adding BC.Density functional theory calculations indicate that flex of PEO chains around Li atoms is suppressed,suggesting the enhanced lithium ion conductivity.Frontier molecular orbitals results suggest that an unfavorable intermolecular charge transfer lead to achieve higher potential for BC composite electrolyte.All solid-state Li metal battery with PEO/Li TFSI/BC CSPE delivers longer cycle life for 600 cycles than PEO/Li TFSI SPE battery(50 cycles).Li symmetrical battery using PEO/Li TFSI/BC CSPE could be stable for 1160 h.

Bacterial Cellulose Templated p-Co3O4/n-ZnO Nanocomposite with Excellent VOCs Response Performance

In this work,p-type Co3O4 decorated n-type ZnO(Co3O4/ZnO)nanocomposite was designed with the assistance of bacterial cellulose template.Phase composition,morphology and element distribution were investigated by XRD,SEM,HRTEM,EDS mapping and XPS.Volatile organic compounds(VOCs)sensing measurements indicated a noticeable improvement of response and decrease of working temperature for Co3O4/ZnO sensor,in comparison with pure ZnO,i.e.,the response towards 100 ppm acetone was 63.7(at a low working temperature of 180℃),which was 26 times higher than pure ZnO(response of 2.3 at 240℃).Excellent VOCs response characteristics could be ascribed to increased surface oxygen vacancy concentration(revealed by defect characterizations),catalytic activity of Co3O4 and the special p-n heterojunction structure,and bacterial cellulose provides a facile template for designing diverse functional heterojunctions for VOCs detection and other applications.

First Otoliths/Collagen/Bacterial Cellulose Nanocomposites as a Potential Scaffold for Bone Tissue Regeneration

In the present work, we report the first bionanocomposite material formed by otoliths/ collagen/ bacterial cellulose (BC) networks (OCBC). This biomaterial is an osteoinductor or be, stimulates the bone regeneration, enabling bigger migration of the cells for formation of the bone tissue regeneration mainly because nanotolith are rich in minerals considered essential to the bone mineralization process on a protein matrix (otolin). The objective in this study was to analyze the regeneration capacity of bone defects treated with this bionanocomposite. Histological experiments shows bone tissue formation with high regularity, higher osteoblast activity and osteo-reabsorption activities areas. The results suggest the potential for this new biomaterial as a scaffold for bone tissue regeneration.

Difficulties in the Use of Ground Bacterial Cellulose(BC)as Reinforcement of Polylactid Acid(PLA)Using Melt-Mixing and Extrusion Technologies

Bacterial cellulose (BC) was ground to make the material suitable for compounding with polylactid acid (PLA). The content of BC in PLA was changed between 5 and 20 wt%. By increasing the BC content of the composite DSC measurements showed an increase of crystallinity (χ c ). Annealing at 90?C resulted in a further increase of χ c . Analysis of the dynamic mechanical behavior showed a sharp decline of the storage module (G’) above the glass transition temperature (T g ) while such a sharp decline did not occur for annealed samples. This indicates that the stiffness of PLA even above T g can be improved by BC and annealing.

Bacterial Cellulose for Several Medicine Areas: Future Insights

Bacterial cellulose (BC)-Nanoskin® has become established as a new biomaterial and can be used in several medicine areas, especially for medical devices mainly in dental and orthopedics applications. In addition, biomaterials have rise because of the increased interest in tissue engineering and regeneratine medicine materials for wound care and skin cancer treatment. The BC process production can be changed by different fermentation process. It has particular properties that make it an ideal candidate as a medical material: high mechanical properties, biocompatibility to the host tissue, and production in various shapes and sizes. This review describes a behavior investigation of this biomaterial in human medicine with bacterial cellulose, skin cancer, covid-19 and 3-D print for medical area.

Improvement in Mechanical Properties and Biocompatibility ofBiosynthetic Bacterial Cellulose/Lotus Root Starch Composites

Bacterial cellulose/lotus root starch(BC/LRS) composites were prepared by cultivating Acetobacter xylinum in nutrient media containing gelatinized lotus root starch. Low concentrations of gelatinized LRS had increased BC production with the maximum value at 6.67 g/L when 5 g/L of LRS was added in the culture media and the composites had thicker and denser fibrils compared with those of BC with low concentrations of LRS(2.5 and 5 g/L). When the concentration of LRS was increased above 7.5 g/L, the morphology of the BC/LRS composites contained more fibril layers that were linked with LRS. The results from X-ray diffraction(XRD) demonstrated that there was no significant difference in structure between BC and BC/LRS composites except a slight increase in crystallinity for BC/LRS composites as the concentration of LRS was lifted up. The tensile tests were performed to display BC/LRS composites prepared with LRS concentration at 2.5 and 5 g/L in media had the tensile strength of 54 and 60 MPa, respectively, which indicated an improvement in mechanical property compared to the unmodified BC(45 MPa). Live/dead assay with chondrocytes seeded on BC/LRS composite revealed higher cell viability ranging from 85% to 90% than BC. Furthermore, cell morphology with typical spindle shape was observed on the surfaces of BC/LRS composite by confocal microscope. Through the overall results, it shows that this study has provided a guidance to prepare BC/LRS composites with better cell biocompatibility and higher mechanical strength than those of BC for the potential use in cartilage tissue engineering.

细菌纤维素基CNFs/ZnO吸波材料的制备及性能

随着电子信息技术的不断发展,电磁污染问题日益严重,高效吸波材料的研究受到越来越多的关注。该文以生物多孔材料细菌纤维素为碳源,采用碳化改性和水热法两步制备了细菌纤维素基CNFs/ZnO复合材料,研究了二水合醋酸锌的浓度对CNFs/ZnO复合材料吸波性能的影响。通过X射线衍射仪(XRD)、冷场发射扫描电子显微镜(FESEM)、矢量网络分析仪(VNA)对复合材料的结构、形貌和吸波性能进行表征。结果表明:CNFs/ZnO复合材料被成功制备,其中碳纳米纤维(CNFs)没有明显的衍射峰,呈无定形状态;碳化和改性CNFs均保持了细菌纤维素三维网络多孔架构的精细纳米纤维微观形貌,但是CNFs变得卷曲且直径明显减小;CNFs/ZnO复合材料中,ZnO被紧密吸引在CNFs表面或随机插入CNFs的空隙中。通过改变二水合醋酸锌的浓度可以控制ZnO在复合材料中的含量,进而调控复合材料的电磁参数,获得良好的阻抗匹配。当二水合醋酸锌的浓度为0.25 mol/L时,ZnO在CNFs上分散得最为均匀,此时CNFs和ZnO的电阻损耗、介电损耗和界面极化等协同作用于三维多孔网络结构上,增加了复合材料对电磁波的多次反射、散射和长程耗散作用。该条件下制备的CNFs/ZnO复合材料,在涂层厚度为2.8 mm、频率为15.1 GHz附近时,其最佳反射损耗为−57.5 dB,有效吸收带宽为7.1 GHz,是一种可靠的复合吸波材料。

PDMS包封CPCM制备三明治结构织物及热性能分析

为解决正十八烷在使用过程中的相泄露问题,以细菌纤维素膜为支撑载体、聚二甲基硅氧烷为包封材料,通过真空浸渍和热固处理制备形稳性复合相变材料。正十八烷浸渍率高达84.9%,潜热能为212.70 J/g,可经受100次热循环测试。经180°弯折后回弹角为156.4°,回弹角相较于包封前提高了131.7%。以复合相变材料为中间层、涤棉混纺织物为外层,经由聚二甲基硅氧烷粘合和固化处理,制得三明治结构织物。吸热饱和后,三明治织物表面温度比普通织物延时降温310 s,在日照模型和人体热管理测试中其覆盖的空间内部温度比普通织物覆盖处降低0.9℃,显示出优异的储热和隔热性能。

含紫苏精油Pickering乳液活性膜的表征及其对冷鲜牛肉品质的影响

该研究以大豆分离蛋白(soy protein isolate, SPI)和壳聚糖纳米粒子(chitosan nanoparticles, CSNPs)为乳化剂制备负载紫苏精油(perilla essential oil, PEO)的Pickering乳液(SPI-CSNPs-PEO Pickering, SCEO),并测定了其粒径、Zeta电位和乳化指数,以进一步验证乳液的稳定性。结果表明,随着油相体积分数的增加,Pickering乳液的Zeta电位的绝对值和乳化指数增加,粒径减小。当油相体积分数为80%时粒径更小,乳滴分散均匀,体系更稳定。以细菌纤维素(bacterial cellulose, BC)和聚乙烯醇(polyvinyl alcohol, PVA)为基材,加入不同体积分数(1%、1.5%、2%、2.5%)的Pickering乳液制备BP/SCEO复合膜。红外光谱和扫描电镜结果显示,SCEO增加了膜表面的粗糙程度,与基膜之间形成氢键相互作用;差示扫描量热法分析表明,复合膜的热稳定性提高。此外,SCEO的加入降低了复合膜水蒸气透过率和拉伸强度而升高了断裂伸长率。其中,BP/SCEO3的性能最好。该方法在一定程度上降低了冷鲜牛肉的菌落总数,延缓了氧化酸败,并将其保质期延长了6 d。因此,负载PEO Pickering乳液的复合膜是一种很有前景的食品包装材料。

纤维素、木质素降解菌的筛选及对菌渣堆肥的影响

为筛选能促进食用菌菌渣堆肥过程中纤维素、木质素降解的高效复合菌,采用羧甲基纤维素钠平板法、刚果红染色法、木质素平板法从菌渣废弃物中对其进行初筛,结合滤纸条崩解试验、苯胺蓝脱色率测定以及纤维素、木质素酶活力测定试验对其进行复筛,之后将其用于好氧堆肥试验,研究该过程中物料理化参数和微生物群落变化,评估其对菌渣纤维素、木质素的降解能力。结果表明,富集得到的纤维素降解菌,6 d内可将滤纸条完全降解,羧甲基纤维素酶(CMCase)、滤纸酶(FPA)、外切葡聚糖酶(C1)和β-葡萄糖苷酶(β-Gase)活力分别达到2.50、7.30、3.43、2.90 U/mL;富集得到的木质素降解菌5 d内苯胺蓝脱色率最大值达92.10%,木质素过氧化物酶(Lac)、漆酶(Lip)和锰过氧化物酶(Mnp)活力分别达到0.80、2.42、1.35 U/mL。堆肥试验结果表明,与自然堆肥处理(CK处理)相比,添加纤维素、木质素2种降解菌处理(XM处理),堆体最高温度为58.77℃,高温(>55℃)持续5 d,纤维素、木质素相对分解率提高值分别为35.83%、54.33%。添加菌剂提高堆肥中期细菌群落丰富度,假单胞菌属(Pseudomonas)、海源菌属(Idiomarina)、谷氨酸杆菌属(Glutamicibacter)、硫代单胞菌属(Thiopseudomonas)、格鲁比卡氏菌属(Globicatella)、极小单胞菌属(Pusillimonas)、溶杆菌属(Lysobacter)、Brumimicrobium等微生物相对丰度增大。冗余分析(RDA)结果表明,温度、pH值、电导率(EC值)是影响堆肥试验中期细菌群落组成的显著因素。综上,筛选的复合降解菌可有效降解纤维素、木质素,并延长堆肥高温期。

柠檬皮/聚乙烯醇/细菌纤维素复合膜的制备及性能研究

该研究首先利用木糖驹形氏杆菌(Taonella mepensis)发酵制备细菌纤维素(bacterial cellulose,BC),然后将其与柠檬皮(lemon peel,LP)、聚乙烯醇(polyvinyl alcohol,PVA)以不同比例混合后制备了一种新型的LP/PVA/BC生物复合膜。分别考察了该复合膜的结构特点、物化特性(热稳定性、厚度、密度、溶胀性、溶解度和孔隙率)、机械性能(抗拉强度和断裂伸长率)以及抑菌活性。结果表明,不同含量的BC对复合膜的微观结构有显著影响,红外光谱和X-射线衍射结果表明,成功地制备了LP/PVA/BC复合膜。复合膜中添加BC可显著降低膜的溶胀性(70.94%~76.68%),提高热稳定性,并对其孔隙率产生影响。同时,还可提升膜的抗拉强度(93.41%~341.57%)和断裂伸长率(4.11%~44.03%)。采用物化特性和机械性能较优的4.8%BC复合膜进行抑菌实验,结果显示该复合膜对沙门氏菌、枯草芽孢杆菌、大肠杆菌及金黄葡萄球菌的抑制率分别为35.93%、48.98%、62.12%和94.93%。以上结果表明,该复合膜显示了较优的物化特性、机械性能和抑菌特性,具有在食品包装材料领域的应用潜力。

堆肥中纤维素降解菌的筛选及复配菌降解性能研究

纤维素作为植物细胞壁的主要成分广泛存在于自然界中,其降解过程对于堆肥发酵、土壤改良及生物质能的开发利用具有重要意义。在堆肥过程中,纤维素降解菌发挥着至关重要的作用。本文旨在将纤维素分解菌株从玉米秸秆堆肥中分离出来,并通过测定相关酶的活性、滤纸条的崩解能力和兼容性、再构建复合菌系、评价降解性能等方法,筛选优良菌株。

微波辅助法制备细菌纤维素-纳米银(BC-AgNps)复合材料及其表征

以细菌纤维素(BC)为模板,不同质量浓度的AgNO_(3)(10、50和200 mg/L)为原料,采用微波辅助法制备细菌纤维素-纳米银(BC-AgNps)复合材料后,再对BC-AgNps进行表征,最后考察它的抑菌性能。经电感耦合等离子质谱检测,复合材料中银含量分别为1.11、2.15和4.86 mg/g;扫描电子显微镜结果显示,AgNps均匀分散在BC上,没有团聚现象发生;使用X线衍射仪及紫外可见光谱均可检测到明显的AgNps特征峰且没有杂峰生成,热稳定性没有发生明显改变。所制备的复合材料具备优良的抑菌性能,对大肠杆菌的抑制率在99%以上,对金黄色葡萄球菌的抑菌率分别为39.90%、95.74%和99.87%,抑菌率随反应体系AgNO_(3)浓度的增加而提高。

细菌纤维素/聚氨酯复合管的制备及其用于人工输尿管的潜力

当输尿管受到损伤时,目前尚未有理想的人工输尿管进行尿路替代,因此亟需开展新型人工输尿管材料研究。本研究以两种细菌纳米纤维素(bacterial nano-cellulose,BNC)管为基底,浸渍复合不同浓度聚氨酯(PU)制备BNC/PU复合管,对复合管结构、理化性能和细胞相容性表征,探究其作为人工输尿管的潜力。结果表明BNC/PU-25%复合管的轴向和径向拉伸性能、缝合强度、爆破压等指标均优于BNC管,且不受人工尿液环境影响,并对小鼠成纤维细胞L929和人源平滑肌细胞的生长增殖无毒害作用。综合评估后认为两种BNC/PU-25%复合管在人工输尿管领域均具有进一步应用的潜力。

磺化酞菁钴-细菌纤维素对苯酚的催化降解性能

采用负载型复合催化剂磺化酞菁钴-细菌纤维素(CoPcS/BC)催化降解苯酚,可以解决苯酚废水传统处理工艺中存在的氧化剂利用率低、催化剂循环性差等问题.探究氧化体系、CoPcS/BC用量、H_(2)O_(2)浓度、pH值和反应温度对苯酚降解的影响,考察反应动力学、CoPcS/BC的循环使用性能和苯酚催化降解产物,并研究CoPcS/BC+H_(2)O_(2)体系对多种酚类污染物的降解效果.实验结果表明,在CoPcS/BC用量为0.25 g/L、H_(2)O_(2)浓度为70 mmol/L、pH为3、反应温度为45℃时,该材料在60 min内对苯酚的降解率可达97.39%,降解过程符合一级动力学模型,且CoPcS/BC可循环回收使用.HPLC实验表明苯酚降解产物为草酸、丙二酸等小分子有机酸.CoPcS/BC+H_(2)O_(2)体系对多种酚类污染物具有较好的降解效果,具有良好的应用前景.

可用于人造血管内层基底的电纺细菌纤维素/聚氨酯复合膜的制备与表征

将聚氨酯与细菌纤维素结合制备复合材料是原位组织工程中探索可降解自愈型人造血管的一个颇有前景的方向。研究了一种制备细菌纤维素(BC)/聚氨酯(PU)复合膜的方法,并评判其用于人造血管内层基底的应用潜力。将细菌纤维素超细粉末与聚氨酯充分混合,利用静电纺丝的技术成功制备细菌纤维素/聚氨酯复合膜,采用傅里叶红外光谱分析仪、DSC差示扫描量热仪、3D电子显微镜、扫描电子显微镜,接触角测量仪及拉伸断裂强力仪等测试仪器对复合膜的外观形貌及物理化学性能进行测试后发现:制备的复合膜同时具有细菌纤维素和聚氨酯的物理化学特性,且具有良好的亲水性及纤维网格结构,有利于提高人造血管内层的生物相容性及抗血栓性相关的血液相容性。结果表明:静电纺丝液溶质质量分数(ω溶质)为29%,其中细菌纤维素质量分数[ω(BC)]为5%~9%,聚氨酯质量分数[ω(PU)]为20%~24%时,制备的复合膜具有较好的物理化学性能,具有作为人造血管内层基底的应用潜力。

细菌纤维素纸质复合微滤膜的开发

分别利用硫酸盐阔叶木浆、硫酸盐针叶木浆和机械浆抄造纸质基膜并测定其过滤性能;采用溶液过滤复合法,通过过滤使分散均匀的细菌纤维素在纸质基膜上形成一层致密薄膜层,即得到细菌纤维素纸质复合微滤膜。结果表明:采用打浆度为10°SR的机械浆抄造定量为90 g/m^2的纸质基膜的过滤性能最好;采用该纸质基膜制备的细菌纤维素纸质复合微滤膜(细菌纤维素复合量6 g/m^2)平均孔径为0.01~1μm,达到微滤膜水平,且强度性能、耐高温性、耐碱性良好。

细菌纤维素/银纳米粒子复合多孔支架材料的制备与表征

以细菌纤维素水凝胶膜、硝酸银和硼氢化钠为原料,制备了细菌纤维素/银纳米粒子多孔复合支架,并利用扫描电子显微镜、能谱分析、X射线衍射、热失重及力学性能测试对多孔复合支架进行研究。结果表明,在细菌纤维素网络结构内部发现了银纳米粒子,表明银纳米粒子进入到细菌纤维素内部,形成细菌纤维素/银纳米粒子复合物;并且,银纳米粒子的粒径随着硝酸银和硼氢化钠浓度的升高而变大;银粒子的引入使细菌纤维素的链规整度有所下降,结晶度变小、力学性能下降,但材料具有了良好的抗菌性能,使其更适用于医用敷料领域。