Stability of layer-by-layer nanofiltration membranes in highly saline streams

Layer-by-layer (LBL) assembly is an essential method for the preparation of nanofiltration (NF) membranes, offering tunable charge and pore size, high water permeability, and good anti-fouling properties, making them highly suitable for resource recovery, seawater desalination, and other fields. Despite their advantages, LBL NF membranes suffer from salinity instability, limiting their use in highly saline streams. This perspective review provides a summary of the fundamental physical and chemical principles of LBL assembly related to the salinity stability of LBL NF membranes. We critically analyze the driving force of LBL assembly, the binding strength of polyelectrolyte (PE) pairs, and the overcompensation of LBL membranes. We also discuss the factors affecting overcompensation level with respect to two different time scales. Furthermore, we examine the relationship between overcompensation level and salinity stability of LBL membranes, considering physical (osmotic pressure) and chemical (Le Chatelier's principle) aspects. Our analysis demonstrates that the salinity stability of LBL NF membranes in highly saline solutions can be improved by selecting PEs with stronger binding strength, increasing the overcompensation level, and chemical crosslinking. These methods not only enhance the salinity stability of LBL NF membranes but also offer greater potential for their future application in highly saline streams

A Two-Step Hydrothermal Synthesis Approach to Monodispersed Colloidal Carbon Spheres

This work reports a newly developed two-step hydrothermal method for the synthesis of monodispersed colloidal carbon spheres (CCS) under mild conditions. Using this approach, monodispersed CCS with diameters ranging from 160 to 400 nm were synthesized with a standard deviation around 8%. The monomer concentration ranging from 0.1 to 0.4 M is in favor of generation of narrower size distribution of CCS. The particle characteristics (e.g., shape, size, and distribution) and chemical stability were then characterized by using various techniques, including scanning electron microscopy (SEM), FT-IR spectrum analysis, and thermalgravity analysis (TGA). The possible nucleation and growth mechanism of colloidal carbon spheres were also discussed. The findings would be useful for the synthesis of more monodispersed nanoparticles and for the functional assembly

Spectral radiative properties and radiation heat transfer of bauxite and SiO2 particles for solar thermal applications

The use of bauxite- and silica-based ceramic particles as solar thermal energy storage materials in concentrated solar power (CSP) plants enables dispatchable grid-scale electricity generation. The solar-to-thermal conversion efficiency is sensitive to both the radiative properties of the particles and the pertinent radiative heat transfer processes. This thesis addresses relevant knowledge gaps to more accurately characterize and radiative properties of particle beds over a wide range of temperatures. The radiative properties of bauxite particles are studied by measuring and modeling the spectral absorptance. Using the effective medium approach, the optical constants are modeled and used to calculate the theoretical absorptance. A high-temperature emissometer is developed to measure the temperature-dependent emittance of bauxite and silica particle beds. The temperature-dependent infrared phonon modes are characterized by fitting the results with a Lorentz oscillator model. Polydisperse silica particles of different types and sizes are measured for reflectance and transmittance. The effective absorption and scattering coefficients are retrieved from measurements and compared with prediction by independent scattering theory to study the effect of dependent scattering. From a geometric optics standpoint, a discrete scale Monte Carlo ray tracing algorithm is developed to simulate the radiative properties of particle beds numerically. The effects of particle volume fraction, particle mixing, and refractive index on radiative properties are analyzed. The findings from this thesis lead to improved estimations of radiative heat transfer in particulate media and designs of particle-based concentrating solar thermal technologies.Ph.D

Study of basic mechanical properties of recycled concrete with various recycled coarse aggregate mixes

Tri vrste recikliranog betona sa šest različitih udjela recikliranog agregata (RAC) ispitano je u četiri različite starosti kako bi se odredila njihova tlačna čvrstoća na uzorcima oblika kocke, odnosno kako bi se utvrdila njihova mehanička svojstva. Sustavno su analizirani oblici sloma, tlačna čvrstoća, krivulje naprezanja – deformacije, maksimalne deformacije te modul elastičnosti betona s recikliranim agregatom. Na temelju dobivenih rezultata predložena su tri izraza za RAC kako bi se opisao odnos između tlačne čvrstoće i udjela zamjene agregata. Razni izrazi za određivanje modula elastičnosti uspoređuju se s rezultatima ispitivanja, nakon čega se prikazuju tri najpovoljnija izraza za tri vrste RAC-a, uključujući i potrebne izmjene, naročito za RAC s miješanim recikliranim agregatom.Three kinds of recycled aggregate concretes (RACs), with six different replacement rates at four ages, are subjected to the standard cube axial compression test to study mechanical properties. Failure modes, compressive strength, stress-strain curves, peak strain, and elastic modulus of RACs are systematically analysed. In addition, three equations are proposed for RACs to describe the relationship between the compressive strength and replacement rate. Comparison between various equations of elastic modulus and test results is presented, and then three most suitable equations are established for three kinds of RACs, including necessary modifications, especially for RAC with mixed recycled aggregates

Self-assembly of particles : some thoughts and comments

Self-assembly can happen to particles at all length scales, including atomic, nano-, meso- and macro-particles. Although widely used in nanoresearch, many nano-structures reported in the literature are not self-assembled, posing some fundamental questions. This paper will briefly review this topic, answering the following questions: what is the current status in self-assembling nanoparticles? Why is it so difficult to produce self-assembled structures of nanoparticles? How can we effectively overcome the difficulty? The important role of controlling forces of various types in relation to different self-assembly techniques is discussed. Self-assembly is demonstrated as a complex problem that still needs intensive multi-scaled studies

Carbonaceous nanostrucutres and their nanocomposites: Synthesis, properties and applications

As a substance rich in carbon, carbonaceous nanostructures is a new class of carbon nanomaterials with properties that differ significantly fromother forms of carbon , and shown potential application in the field of heavy metal sorption, catalytic, CO2 fixation , energy storage materials, andbiomedicine. From the viewpoint of economic, environmental and societal issues , the hydrothermal carbonization (HTC) process form biomasspresents superior characteristics that make it a promising route for the synthesis of these functional carbonaceous materials .In this thesis, a brief introduction of the relative research and a literature review on the carbonaceous nanostructures and their nanocompositeswere presented in Chapter 2, the latest advances in the synthesis of functional carbonaceous materials from different biomasses or biomassderived sources via the HTC process will be outlined.Chapter 3 systematically described the preparation of monodispersed colloidal carbonaceous spheres (CCS) with different size by a facile twostephydrothermal method. We demonstrated that the obtained monodispersed CCS can be controlled from 160 to 400 nm in diameter with astandard deviation no more than 8%. The success of this synthesis strongly depends on the accuracy control of the amount of seeds andmonomers (glucose).In chapter 4 , high-quality carbonaceous nanotubes were prepared through one-pot hydrothermal process with well-controlled dimensions and highyield . The success of this method should first be attributed to the formation of silver@carbonaceous composites nanocables and then the etchremoval of their silver core nanowires can be easily inspired by manipulating the dynamic equilibrium from growth to oxidative etching viacontrolling reaction temperature .To demonstrate the potential of carbonaceous nanomaterials for the biomedicine application, in chapter 5 and 6, successful synthesis of CarboncoatedAu and Fe3O. nanocomposites were achieved respectively by modifying relative as-prepared nanoparticles with polymerized glucose underhydrothermal condition . In vitro experimental results show that overcoating by glucose- derived material is an effective method to reduce thecytotoxicity of nanoparticles without significant effect on "heat generating" ability.Finally, the conclusions were summarized in Chapter 7

Immunotherapy for Triple-Negative Breast Cancer

Triple-negative breast cancer (TNBC) is characterized by extensive tumor heterogeneity at both the pathologic and molecular levels, particularly accelerated aggressiveness, and terrible metastasis. It is responsible for the increased mortality of breast cancer patients. Due to the negative expression of estrogen receptors, progesterone receptors, and human epidermal growth factor receptor 2, the progress of targeted therapy has been hindered. Higher immune response in TNBCs than for other breast cancer types makes immunotherapy suitable for TNBC therapy. At present, promising treatments in immunotherapy of TNBC include immune checkpoints (ICs) blockade therapy, adoptive T-cell immunotherapy, and tumor vaccine immunotherapy. In addition, nanomedicines exhibit great potential in cancer therapy through the enhanced permeability and retention (EPR) effect. Immunotherapy-involved combination therapy may exert synergistic effects by combining with other treatments, such as traditional chemotherapy and new treatments, including photodynamic therapy (PTT), photodynamic therapy (PDT), and sonodynamic therapy (SDT). This review focuses on introducing the principles and latest development as well as progress in using nanocarriers as drug-delivery systems for the immunotherapy of TNBC